General Announcement:

As of 14:00 UT 11 Jan 08, the words "transient" and "Transient" have been added
to the list of required words to appear in the Subject-line of submitted Circulars.
Given the odd nature of this object, these new words were needed.

As background, the motivation for requiring one of these keywords to appear
in the Subject-line is to prevent spam from being distributed.  This is one
of several spam prevention mechanisms.  This set of mechanisms has been
very successful in that of the approximate 50,000 spams received per year,
none have been distributed.

////////////////////////////////////////////////////////////////////////
ATEL #1353                                                           ATEL #1353

Title:          Extremely Bright X-ray Transient Likely in NGC 2770
Author:         Edo Berger and Alicia Soderberg (Princeton University)
Queries:        eberger@astro.princeton.edu
Posted:         10 Jan 2008;  13:52  UT
Subjects:       X-ray, Transients

Follow-up observations of SN2007uy with the Swift/XRT reveal a new transient
source about 95 arcsec away from the SN position at RA=09:09:30.7, Dec=+33:08:19
(J2000).  This position coincides with the outskirts of the host galaxy
of SN2007uy (NGC 2770).  The object was not detected in the previous observation
of SN2007uy (ATEL #1350) and is detected only in the first 1 ksec of the
new observation.  During that time the light curve is FRED-like with a
rise time of about 50 sec and a decay to the background level by about
600 sec.  The source is not detected in the subsequent 4 ksec of data that
intermittently cover 5-24 ksec after the flare.  The average count rate
is about 1 cps, which at the distance of NGC2770 (d=27 Mpc) corresponds
to a luminosity of about 4x10^42 erg/s.  This is in excess of 10^4 times
the Eddington luminosity of a solar mass object.  No coincident object
is detected in the simultaneous Swift/UVOT data or in archival DSS and
2MASS images.  Alternatively, this may be a foreground bright stellar
flare (with L_X/L_bol=10^-3), but this would require a solar-type star
at a distance of only 25 pc or an M dwarf at 2 pc, both of which would
be detectable in optical and near-IR images.  An extreme stellar flare
with L_X=L_bol would require distances of about 500 and 50 pc, respectively.
Given the high luminosity at the distance of NGC 2770, the light
curve shape, and the integrated energy of about 10^45 erg, we hypothesize
that this object may be a weak X-ray Flash, perhaps analogous to GRB980425/SN1998bw.
Deep optical and near-IR observations to search for a counterpart
are encouraged.  Radio observations are in progress.

////////////////////////////////////////////////////////////////////////
ATEL #1354                                                           ATEL #1354

Title:          Radio observations of the transient in NGC 2770
Author:         Alicia Soderberg (Princeton)
Queries:        alicia@astro.princeton.edu
Posted:         10 Jan 2008;  14:49  UT
Subjects:       Radio, Transients

Beginning at 2008 Jan 10.2 UT, I observed the radio bright Type Ibc SN
2007uy with the VLA as part of a monitoring campaign to study the non-thermal
emission from the SN.  I note that the position of the extremely bright
X-ray transient within NGC 2770 (ATEL 1353) lies within the field-of-view
of the radio observation.   No radio source is detected at the position
of the X-ray transient.  At 8.46 GHz, I place an upper limit of 0.1 mJy
on the flux density of the transient source.  Radio observations are on-going.

////////////////////////////////////////////////////////////////////////
ATEL #1355                                                           ATEL #1355

Title:          A Giant X-ray Flare in NGC 2770
Author:         A.K.H. Kong (National Tsing Hua Univ., Taiwan) and T.J. Maccarone
                (Southampton)
Queries:        akong@phys.nthu.edu.tw
Posted:         10 Jan 2008;  15:30  UT
Subjects:       X-ray, Soft Gamma-ray Repeaters, Transients

We report a giant X-ray flare event detected in a Swift observation of
SN2007uy.  On 2008 Jan 9 UT, Swift performed a 5 ks follow-up observation
of SN2007uy (ATel #1350).  While SN2007uy was not detected with XRT, a
bright X-ray point source was found ~90 arcsec from SN2007uy.  The derived
position of this new X-ray source is R.A.=9h09m30.6s, Decl.=+33:08:18
(J2000) with a 3.6 arcsec error circle (90% confidence) and the source
is located near the edge of the edge-on galaxy NGC 2770.  The source has
over 600 counts in the 0.3-10 keV band and the light curve indicates
that all X-ray events are from the first ~600 sec.  The X-ray light curve
shows a fast-rise-exponential-decay profile with a rise time of ~50 sec
and an e-folding time of ~160 sec.  The X-ray spectrum can be fit with
a power-law model with N_H=6e21 cm^-2 and a photon index of 2.1.  We note
that the Galactic N_H to the direction of NGC 2770 is 2e20 cm^-2.  If the
source is associated with NGC 2770 (d=29 Mpc), the unabsorbed 0.3-10
keV luminosity is 8.3e42 erg/s.   

We can rule out a foreground object due to the relatively hard X-ray
spectrum and the high absorption.  We can also rule out an AGN because
a ~10-20 second doubling timescale for the luminosity early in the flare
requires the black hole mass be less than 10^6 solar masses by light
crossing timescale arguments.  Finally, we propose that the event may
be a giant flare from a soft gamma-ray repeater similar to SGR 1806-20
(Hurley et al. 2005). 

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7159
SUBJECT: Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
DATE:    08/01/10 16:12:03 GMT
FROM:    Edo Berger at Princton U  <eberger@astro.princeton.edu>

E. Berger and A.M. Soderberg (Princeton University) report:

"Follow-up observations of SN2007uy with the Swift/XRT reveal a new transient 
source about 95 arcsec away from the SN position at RA=09:09:30.7, 
Dec=+33:08:19 (J2000).  This position coincides with the outskirts of the host 
galaxy of SN2007uy (NGC 2770). The object was not detected in the previous 
observation of SN2007uy (ATEL #1350) and is detected only in the first 1 ksec 
of the new observation.  During that time the light curve is FRED-like with a 
rise time of about 50 sec and a decay to the background level by about 600 sec. 
The source is not detected in the subsequent 4 ksec of data that intermittently 
cover 5-24 ksec after the flare. The average count rate is about 1 cps, which 
at the distance of NGC2770 (d=27 Mpc) corresponds to a luminosity of about 
4x10^42 erg/s.  This is in excess of 10^4 times the Eddington luminosity of a 
solar mass object.  No coincident object is detected in the simultaneous 
Swift/UVOT data or in archival DSS and 2MASS images.

Alternatively, this may be a foreground bright stellar flare (with 
L_X/L_bol=10^-3), but this would require a solar-type star at a distance of 
only 25 pc or an M dwarf at 2 pc, both of which would be detectable in optical 
and near-IR images.  An extreme stellar flare with L_X=L_bol would require 
distances of about 500 and 50 pc, respectively.

Spectral fitting indicates a best-fit absorbed power law spectrum with 
NH=4x10^21 cm^-2 (in excess of the Galactic value of 2x10^20 cm^-2) and a 
photon index of 2.1.  The unabsorbed luminosity is 5x10^42 erg/s.  The high 
column density likely rules out a Galactic origin.

Given the high luminosity at the distance of NGC 2770, the light curve shape, 
and the integrated energy of about 10^45 erg, we hypothesize that this object 
may be a weak X-ray Flash, perhaps analogous to GRB980425/SN1998bw.

Deep optical and near-IR observations to search for a counterpart are 
encouraged.  Radio observations are in progress."

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7160
SUBJECT: Bright X-ray Transient (a XRF? ) in NGC 2770 - A SN optical counterpart?
DATE:    08/01/10 20:11:22 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

J. Deng and Y. Zhu (NAOC) report:

We took a 60s unfiltered CCD image and a 600s R-band image of NGC 2770 on 2008 Jan 10 18:19 UT and 18:22 UT with the BFOSC 
instrument of the NAOC 2.16m telescope at the Xinglong Observatory, China. An optical source was clearly seen in both images 
which was conincident in position with the X-ray transient reported in GCN 7159. It was roughly 2 mag fainter than SN 2007uy in 
the same galaxy. The source was not seen in the archival SDSS image of NGC 2770 that we retrieved from nedwww.ipac.caltech.edu. 
We suspect that this source is the SN counterpart of the X-ray transient (a XRF). Spectroscopic observations are in progress 
despite the cloudy weather condition. 

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7161
SUBJECT: Possible XRF in NGC 2770 - NOT observations of the optical counterpart
DATE:    08/01/11 05:07:06 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene@astro.ku.dk>

Christina C. Thoene, Daniele Malesani, Jens Hjorth (DARK), Pall Jakobsson
(Univ. of Hertfordshire), Matt Bayliss and Benjamin Koester (Univ. of
Chicago) report:

We observed the optical counterpart of the proposed XRF in NGC 2770
(Berger & Soderberg, GCN 7159; Deng & Zhu, GCN 7160) with NOT/StanCam on
Jan 11, starting at UT 00:05 in UBVRI.
The optical counterpart reported in Deng & Zhu GCN 7160 is clearly
detected in all bands. Based on archival photometric zeropoints from
the NOT webpages, we obtain the following magnitudes:

U   19.9
B   20.2
V   19.3
R   18.7
I   18.1

If the transient is a SN related to the XRF and associated to NGC 2770, it
would be about 3 mag fainter than SN 1998bw at the same epoch.
At the moment, however, we cannot determine any possible variability or
get any conclusive evidence on the nature of the transient. Spectroscopic
observations are on the way.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7162
SUBJECT: Bright X-ray transient / possible XRF in NGC 2770: TNG R imaging
DATE:    08/01/11 06:56:21 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

V. D'Elia, L.A. Antonelli (INAF/OAR), S. Covino (INAF/OABr), E. Maiorano 
(INAF/IASF Bo), A. Magazzu' and N. Pinilla-Alonso (INAF/TNG), report on 
behalf of the CIBO collaboration:

We took a 300s R-band image of NGC 2770 on 2008 Jan 11, starting at 
01:30:14 UT, with the DOLoRes camera on the TNG telescope located in the 
Canary Islands (Spain). An optical source, likely coincident with the 
object reported by Deng & Zhu (GCN 7160) and Thoene et al. (GCN 7161), 
is clearly detected at a position consistent with that reported for the 
X-ray transient (Berger & Soderberg, GCN 7159). The coordinates of the 
object are (J2000):

RA: 09:09:30.65
Dec: +33:08:20.3

with an estimated error of 0.3" (against USNO-B1.0).

We estimate the magnitude to be R~18.0 based on the USNO catalog (e.g. 
assuming R=17.2 for the star at 09:09:37.28, +33:09:35.1). A finding 
chart is posted at the following link:

http://www.brera.inaf.it/utenti/davanzo/public/grb/XRF080109/080109_finder.jpg

Further analysis is underway.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7163
SUBJECT: Early OT detection of XRF in NGC 2770 in Asiago frames
DATE:    08/01/11 11:08:16 GMT
FROM:    Stefano Valenti at U di Ferrara,Italy  <valenti@fe.infn.it>

S. Valenti, M. Turatto, H. Navasardyan, S. Benetti and E. Cappellaro report:

The optical counterpart of the transient source in NGC 2270 (cfr. GCN 7159)
was present on images of SN2007uy taken with the 1.8m telescope of the Asiago
Observatory (+AFOSC) on Jan. 10.01 (10.5h after the Swift detection) and
not visible
(limit magnitude  ~ 21) on Jan.  7.00.
The transient was of mag ~ 19 in V,   fainter than SN 2007uy by 3 and 2.8
magnitude in V and R,
respectively.  Following the report of J. Deng and Y. Zhu (GCN7160) that
the transient was roughly 2 magnitudes  fainter than SN2007uy on Jan. 10.76,
in R band, it seems that the luminosity of the transient is rising
rapidly, supporting the very fortunate possibility  that Swift has
observed, in
real time, the explosion of a massive star. A image of the transient can
be found at:
http://www.eso.org/~svalenti/homepage/transient.jpg

////////////////////////////////////////////////////////////////////////
ATEL #1356                                                           ATEL #1356

Title:          Swift UVOT Observations of the X-ray transient in NGC 2770
Author:         A.K.H. Kong (NTHU), A. Soderberg, E. Berger (Princeton), N.
                Rea (Amsterdam), T. Maccarone (Southampton)
Queries:        akong@phys.nthu.edu.tw
Posted:         11 Jan 2008;  12:59  UT
Subjects:       Optical, X-ray, Transients

Swift performed an observation of the X-ray transient in NGC 2770 on 2008
Jan 11 02:45UT. No X-ray source was detected in the 1.1ks observation.
However, the optical transient (e.g., GCN #7163) was clearly detected
in the U, V, and B bands of the UVOT. The source was marginally seen
in the UVW1 image. The very rough B and V magnitude is 18.8 and 18.4,
respectively. The Swift observations indicate that the optical transient
becomes brighter in the past 24 hours. We note that the optical transient
was not seen in the UVOT observations taken on 2008 Jan 9 (ATel #1353,
#1355). 

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7164
SUBJECT: Swift UVOT Observations of the X-ray transient in NGC 2770
DATE:    08/01/11 13:09:55 GMT
FROM:    Albert Kong at MIT  <akong@space.mit.edu>

A.K.H. Kong (NTHU), A. Soderberg, E. Berger (Princeton), N. Rea 
(Amsterdam), T. Maccarone (Southampton) report:

Swift performed an observation of the X-ray transient in NGC 2770 on 
2008 Jan
11 02:45UT. No X-ray source was detected in the 1.1ks observation. However,
the optical transient was clearly detected in the U, V, and B bands of the
UVOT. The source was marginally seen in the UVW1 image. The very rough B 
and V
magnitude is 18.8 and 18.4, respectively. The Swift observations 
indicate that
the optical transient becomes brighter in the past 24 hours. We note 
that the
optical transient was not seen in the UVOT observations taken on 2008 Jan 9
(ATel #1353,1355).

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7165
SUBJECT: Optical Spectroscopy of the Transient in NGC 2770
DATE:    08/01/11 15:25:19 GMT
FROM:    Alicia Soderberg at Caltech  <ams@astro.caltech.edu>

A. Soderberg, E. Berger (Princeton), D. Fox, A. Cucchiara (Penn State), A. 
Rau, E. Ofek, M. Kasliwal, and S. B. Cenko (Caltech) report on behalf of a 
large collaboration:

"We observed the optical counterpart to the X-ray transient in NGC 2770 
(GCNs 7159, 7160) with the Gemini-N/GMOS and Palomar 200-inch/COSMIC 
spectrographs beginning at Jan 11.3 UT.  The exposure times were 2x600 sec 
and 2x900 sec for the Gemini and Palomar data, respectively. A preliminary 
analysis of the reduced spectra reveals that the optical counterpart has a 
smooth, featureless continuum.  We note that there is some suggestion 
of a broad bump near 5500 Ang which may indicate the emergence of SN 
features.

Further analysis is in progress."

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7166
SUBJECT: X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus
DATE:    08/01/11 15:44:16 GMT
FROM:    Denis Denissenko at IKI, Moscow  <denis@hea.iki.rssi.ru>

D. Denisenko (IKI, Moscow), S. Korotkiy (Ka-Dar obs.), T. Kryachko
(Astrotel obs., KSU), B. Satovskiy (Astrotel obs., KSU),
K. Sokolovsky (ASC LPI, SAI MSU) report: 

We took three 300-sec unfiltered images of NGC 2770 between 19:00 and 19:18 
UT
on 2008 Jan 10 with 300-mm f/7.7 robotic telescope equipped with STL-11000M 
CCD camera. The telescope is located at Kazan State University Astrotel 
observatory (Karachay-Cherkessia, Russia). The optical source reported by 
Deng & Zhu (GCN 7160) and Thoene et al. (GCN 7161) is clearly detected on 
individual images with SNR=18. Using the same comparison star as in D'Elia 
et al. (GCN 7162), we have measured unfiltered magnitude (with R zero-point) 
of the transient 18.1+/-0.1
(JD 2454476.2979). 

The finding chart is available at
ftp://scan.sai.msu.ru/pub/XRT_NGC2770/OT-NGC2770-Astrotel.jpg 

The individual fits images can be downloaded from
ftp://scan.sai.msu.ru/pub/XRT_NGC2770/ 

This message can be cited.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7167
SUBJECT: Opticall follow-ups for the X-ray transient in NGC 2770
DATE:    08/01/11 15:44:27 GMT
FROM:    Yuji Urata at Saitama U  <urata@asiaa.sinica.edu.tw>

Y. Urata (ASIAA/Saitama-U), M. Im, I. Lee (Seoul Univ), 
K.Y Huang (ASIAA), D. Kinoshita, T.W Chen (NCU) 
on behalf of EAFON report:

"We have observed the position of the X-ray flare in NGC 2770 (Atel
1353, 1355, GCN 7159) using Lulin 1m telescope and Mt Lemmon 1m
telescope operated by KASI Korea. The optical counterpart (e.g. GCN
7160, Atel 1356) is clearly detected by both of observations.  Our
preliminary analysis implies there is no significant variability
between 2008-01-10 18:17 (Lulin) and 2008-01-11 06:16 (Mt. Lemmon).
However, the brightness seems like gradually increasing.

Further observations and analysis are in progress."

This message can be sited.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7168
SUBJECT: Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
DATE:    08/01/11 20:46:38 GMT
FROM:    Stefan Immler at NASA/GSFC  <immler@milkyway.gsfc.nasa.gov>

S. Immler (NASA/UMCP/GSFC), A. Cucchiara (PSU),  D. Fox (PSU),
A.M. Soderberg (Princeton U), E. Berger (Princeton U), K. Page (Leicester
U), P. O'Brian (Leicester U), D. Burrows (PSU), and N. Gehrels (GSFC),
report on behalf of the Swift team:

An optical counterpart to the X-ray transient in NGC 2770, now SN 2008D
(Atel 1353, 1355, GCN 7159-7167, CBET 1202), was marginally detected
with the Swift Ultraviolet/Optical Telescope (UVOT) in observations
starting 2008-01-09 13:32:53 UT. The following UVOT magnitudes were
measured: b = 20.50.3 (412 s exposure time) and u = 20.20.4 (412 s).
Upper limits were established for the other UVOT filters, v > 19.9 (412 s,
3-sigma), uvw1 > 20.4, uvm2 > 20.3, and uvw2 > 20.8.

The following UVOT magnitudes were measured for observations
starting 2008-01-11 02:37:28 UT:  v = 18.50.2 (216 s exposure time),
b = 18.90.1 (353 s), u = 18.60.1 (664 s), uvw1 = 19.80.2 (1707),
uvm2 > 19.8 (3-sigma UL, 571 s), uvm2 = 20.10.3 (864 s), and uvm2 >
20.4 (864 s).

We note that no optical/ultraviolet source was detected at the location of
the transient during routine observations of SN 2007uy on 2008-01-06
00:31:23 UT, down to the following 3-sigma upper limits: v > 20.2 (808 s
exposure time), b > 21.1 (808 s), u > 20.7 (808 s), uvw1 > 20.8 (1619 s),
uvm2 > 20.7 (2187 s), uvw2 > 21.2 (3234 s).

These magnitudes are on the UVOT photometric system (see Poole et al.,
2007, MNRAS, 383, 627) which in the optical is close to the Johnson UBV
system. They have not been corrected for Galactic extinction of E(B-V) =
0.023 mag (Schlegel et al. 1998, ApJ 500, 525). The UVOT photometry
and colors are similar to the early UVOT phase of SN 2006aj/GRB060218
(e.g., Campana et al. 2006, Nature 442, 1008) and consistent with an
emerging supernova, although other possibilities cannot be ruled out.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7169
SUBJECT: Transient in NGC 2770: spectroscopic evidence for a SN
DATE:    08/01/11 21:01:14 GMT
FROM:    Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center  <malesani@astro.ku.dk>

D. Malesani, J. Hjorth (DARK), P. Jakobsson (Univ. Hertfordshire), P.M. 
Vreeswijk, C.C. Thoene, J.P.U. Fynbo, D.J.  Watson, J. Sollerman (DARK), 
N.R. Tanvir (Univ. Leicester), T. Stanke (ESO), report on behalf of a 
larger collaboration:

We observed the optical transient in NGC 2770 (Berger & Soderberg, GCN 
7159; Deng & Zhu, GCN 7160), denoted SN 2008D (Li & Filippenko, IAUC 
1202), with the ESO VLT equipped with FORS2, starting on 2008 Jan 11, 
07:17 UT. Two spectra, at low and moderate resolution, were acquired, 
covering the wavelength ranges ~3700-6350 and ~3800-9000 AA. The 
exposure times were 10 and 15 minutes, respectively. The two spectra, 
after flux calibration, agree very well in the overlap region, and the 
peak S/N is ~60 and ~40, respectively.

We detect a strong, red continuum revealing several broad features and 
bumps. The afterglow spectrum does not display a power-law shape. We 
also detect Na I D in absorption at z = 0.0069. This redshift is very 
similar to that of the host z=0.0071, as measured for the Halpha and 
Hbeta lines in emission superimposed on the transient. The detection of 
Na I D confirms that the object is of extragalactic origin. It also 
implies that it is subject to significant extinction. Although 
uncertain, using the relation by Munari & Zwitter (1997, A&A, 318, 269), 
we estimate E(B-V) to be larger that ~0.5 mag based on the equivalent 
width of the 5890 A line EW = 0.67 AA. Such relatively large extinction 
is consistent with the detection of excess column density in the X-ray 
spectra of the flare (Berger & Soderberg, GCN 7159).

The spectral shape of the transient rules out a significant nonthermal 
afterglow component. The presence of broad features is reminiscent of SN 
spectra, although it is not straightforward to identify the involved 
transitions. The lack of prominent Silicon and Hydrogen lines suggests 
the SN is not of type Ia or II. By exclusion, we suggest the transient 
is a SN of type Ib/c. The features are not as broad as in the earliest 
spectra of GRB-associated SNe such as SN1998bw and SN2006aj.

The luminosity of the event is also comparable to that of other 
core-collapse SNe associated with GRBs. The object had V~19.3 
approximately 1.5 days after the X-ray transient (Thoene et al., GCN 
7161). Taking into account the large extinction (> 1.5 mag in V), the 
luminosity is comparable with that of core-collapse SNe soon after the 
explosion. As noted by several authors, the available light curve is 
also consistent with a SN (Valenti et al., GCN 7163; Kong et al., GCN 
7164, Li & Filippenko, CBET 1202).

In conclusion, the bright absolute magnitude of the object, M_V < -14,  
the broad spectral features, and the lack of H and Si strongly suggest 
that the transient in NGC 2770 is a SN of type Ib/c.

Lastly, we note that the transient does not seem to lie in an intense 
star forming region of its host, as suggested by the modest nebular 
features detected in our spectrum and the absence of prominent emission 
at the position of the optical transient (D'Elia et al., GCN 7162) in 
the archival SDSS images. We caution that strong extinction may affect 
this arguments.

We acknowledge excellent support of the observing staff at Paranal, in 
particular Cedric Ledoux, Linda Schmidtobreick, and Antonio de Ugarte 
Postigo.

[GCN OPS NOTE(13jan08): Per author's request, the "IAUC 1202" citation
was changed to "CBET 1202" (at the end of the 4th paragraph).]

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7170
SUBJECT: Refined Swift-XRT analysis of the transient in NGC 2770 
DATE:    08/01/11 21:01:20 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U Leicester), D. Burrows (PSU), P.T. O'Brien (U Leicester), 
A.M. Soderberg (Princeton U), E. Berger (Princeton U), S. Immler 
(NASA/UMCP/GSFC), A. Cucchiara (PSU), D. Fox (PSU) and N. Gehrels 
(NASA/GSFC) report on behalf of the Swift team:

Following the initial detection of an X-ray transient in NGC 2770 on 
2008-01-09 (GCN Circ. 7159, ATel 1353 - Berger & Soderberg; ATel 1355 - 
Kong & Maccarone), a Swift Target of Opportunity observation was performed 
between 2008-01-10 and 2008-01-11. 

As previously mentioned in GCN Circ. 7159, the X-ray data are seen to rise 
at the beginning of the XRT observation. The light-curve then decays 
steeply for the following 700-800 seconds, with a power-law index of 3.3 
+/- 0.4. Between the end of this first orbit of data and the start of the 
next (a gap of approximately 5 ks), the decay flattens off, and the 
count-rate remains close to constant [around (2.5-3)e-3 count s^-1] for at 
least 180 ks.

There is spectral evolution during the first orbit, with the data 
softening for the first ~400 seconds, before slightly hardening again. The 
time-averaged spectrum can be well modelled by an absorbed power-law, with 
Gamma = 2.1 +/- 0.2, and NH = (6.1 +1.3/-1.1)e21 cm^-2.

This field was also observed on 2008-01-06, before the transient was 
detected. Although there may be another faint, nearby source, the upper 
limit on the count-rate for this transient is ~7e-4 count s^-1 (0.3-10 
keV) at this early time.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7171
SUBJECT: Spectroscopic classification of SN 2008D (Transient in NGC 2770)
DATE:    08/01/11 22:07:31 GMT
FROM:    Stefano Valenti at U di Ferrara,Italy  <valenti@fe.infn.it>

S.  Valenti  (Universita'  di  Ferrara);  D.   Fugazza,  E.   Maiorano
(Istituto Nazionale di Astrofisica - INAF - Osservatorio Astronomico di
Bologna); V.  D'Elia, L.A.  Antonelli (INAF-Ossevatorio Astronomico di
Roma);   S.    Covino   (INAF-Osservatorio  Astronomico   di   Brera);
A. Magazzu' and  N.  Pinilla-Alonso (INAF-Telescopio Nazionele Galileo
(TNG)); M.  Della Valle (INAF-Osservatorio Astrofisico di Arcetri); G.
Chincarini  (Universita' degli  Studi  di Milano  Bicocca); E.   Pian,
P.A.    Mazzali    (INAF-Osservatorio    Astronomico   di    Trieste);
A.  Harutyunyan, S. Benetti  (INAF-Osservatorio Astronomico di Padova)
and behalf of the CIBO collaboration report:

The preliminary reduction of a spectrum
of SN 2008D (Transient in NGC 2770) taken with TNG+LRS
(range 350 - 780 nm) on Jan 11.1 resembles
that of the energetic type Ic SN 2006aj 3 days after explosion (Pian et
al, 2006, Nature 442 1011). The SiII-635.5nm  feature shows  an  higher
expansion velocity  than in  SN  2006aj.  The  bluer  bumbs seen  in SN
2006aj spectrum, centered at  about 440  and 500  nm, are not  yet well
developed, also
suggesting an higher expansion velocity.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7172
SUBJECT: XRF in NGC 2770: Search for X-ray periodicity
DATE:    08/01/11 22:21:43 GMT
FROM:    Eran Ofek at Tel Aviv U.  <eran@wise1.tau.ac.il>

E. O. Ofek, S. R. Kulkarni, M. M. Kasliwal, A. Rau, S. B. Cenko (Caltech),
D. B. Fox (Penn State) on behalf of a larger collaboration.

We inspected the Swift X-ray observations of the X-ray transient
associated with NGC 2770 (Berger & Soderberg 2008; ATel 1353; GCN 7159).
We looked for periodicity in the X-ray data that may hint
on association with a fast rotating object.
We do not identify any (non-instrumental) periodicity in the
data, below the sampling frequency of 0.4 Hz.
We estimate that the fraction of photons that are modulated
periodically (if at all) is smaller than 10%.

The X-ray event started approximately at the beginning
of the XRT observation at UTC 2008 Jan 09.5652. Peak flux (in 10 s
intervals) was achieved about 65 s later.

We note that the analysis is based on 697 photons, within 20 pixels from the
transient location and detected within 1000 s of the
beginning of the XRT observation.

////////////////////////////////////////////////////////////////////////
                                                  Electronic Telegram No. 1204
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVA 2008D IN NGC 2770
      S. Blondin, Harvard-Smithsonian Center for Astrophysics (CfA), on
behalf of the CfA Supernova Group; T. Matheson, National Optical Astronomy
Observatory; and M. Modjaz, University of California at Berkeley, report
that a spectrum (range 320-840 nm) of 2008D (cf. CBET 1202), obtained on
Jan. 11.41 UT by P. Berlind with the MMT 6.5-m telescope (+ Blue Channel
spectrograph), shows it most likely to be a peculiar type-Ic supernova in
its early phases.  The spectrum consists of a relatively blue continuum,
with P-Cyg profiles (FWHM of approximately 10000 km/s) that are
characteristic of a supernova spectrum blueward of 550 nm, and an extremely
broad emission feature peaking at approximately 630 nm that is similar to
the [O I] doublet (rest 630.0, 636.4 nm) seen in the spectra of broad-line
type-Ic supernovae around maximum light.  More specifically, the double-
absorption feature centered on 420 nm resembles that seen in the earliest
spectrum of the normal type-Ic supernova 1990aa (cf. IAUC 5087, 5111;
Matheson et al. 2001, A.J. 121, 1648), while the broad feature centered on
630 nm resembles the [O I] bump seen in spectra of the broad-line type-Ic
supernova 1998bw (associated with GRB 980425; cf. IAUC 6895, 6901; Patat
et al. 2001, Ap.J. 555, 900) around maximum light (roughly three weeks
after the gamma-ray-burst detection).
     Blondin et al. add that their spectrum is not consistent with the
description given by Soderberg et al. in GCN 1765, who report on a "smooth,
featureless continuum" with "some suggestion of a broad bump near 5500
Angstroms".  However, based on other spectra of familiar objects fully
reduced from the same night, Blondin et al. are confident that their flux
and wavelength calibrations are accurate.  The separation in time between
the MMT spectrum and the one described in GCN 1765 is only 0.1 day.
Blondin et al. clearly detect narrow emission lines at the supernova
position, consistent with the NED redshift of 1934 km/s for NGC 2770 (from
The Updated Zwicky Catalog, http://tdc-www.harvard.edu/uzc/).  Also,
interstellar Na I D absorption at that redshift is visible in the spectrum
with an equivalent width of 0.2 nm.  A comparison plot can be seen at URL
http://www.cfa.harvard.edu/supernova/spectra/sn2008D_comp.gif; note that,
in this plot, the spectrum of SN 1990aa had to be blueshifted by 5500 km/s
in order for prominent spectroscopic features to match up with those
present in SN 2008D, while that of SN 1998bw has been redshifted by 13000
km/s for the same reason.

     S. Valenti, Universita di Ferrara; D. Fugazza and E. Maiorano, Istituto
Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Bologna; V.
D'Elia and L. A. Antonelli, INAF, Ossevatorio Astronomico di Roma; S. Covino,
INAF, Osservatorio Astronomico di Brera; A. Magazzu and N. Pinilla-Alonso,
INAF, Telescopio Nazionele Galileo (TNG); M. Della Valle, INAF, Osservatorio
Astrofisico di Arcetri; G. Chincarini, Universita' degli Studi di Milano
Bicocca; E. Pian and P. A. Mazzali, INAF, Osservatorio Astronomico di Trieste;
and A. Harutyunyan and S. Benetti, INAF, Osservatorio Astronomico di Padova,
report that preliminary reduction of a spectrogram of 2008D, taken with the
TNG (+ LRS; range 350-780 nm) on Jan. 11.1 UT, shows that the spectrum
resembles that of the energetic type-Ic supernova 2006aj (cf. IAUC 8674) at
three days after explosion (Pian et al. 2006, Nature 442, 1011).  The Si II
635.5-nm feature shows a higher expansion velocity than in the spectrum of
2006aj.  The bluer bumps seen in the 2006aj spectrum, centered at about 440
and 500 nm, are not yet well developed, also suggesting a higher expansion
velocity.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 January 11                  (CBET 1204)              Daniel W. E. Green

////////////////////////////////////////////////////////////////////////
                                                  Electronic Telegram No. 1205
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVA 2008D IN NGC 2770
     NOTE:  this text replaces that on CBET 1204.

     S. Blondin, Harvard-Smithsonian Center for Astrophysics (CfA), on
behalf of the CfA Supernova Group; T. Matheson, National Optical Astronomy
Observatory; and M. Modjaz, University of California at Berkeley, report
that a spectrum (range 320-840 nm) of 2008D (cf. CBET 1202), obtained on
Jan. 11.41 UT by P. Berlind with the MMT 6.5-m telescope (+ Blue Channel
spectrograph), shows it most likely to be a peculiar type-Ic supernova in
its early phases.  The spectrum consists of a relatively blue continuum,
with P-Cyg profiles (FWHM of approximately 10000 km/s) that are
characteristic of a supernova spectrum blueward of 550 nm, and an extremely
broad bump peaking at approximately 630 nm (with an associated absorption
at 590 nm) that is similar to the Si II line (rest 635.5 nm) seen in the
spectra of broad-line type-Ic supernovae around maximum light.  More
specifically, the double-absorption feature centered on 420 nm resembles
that seen in the earliest spectrum of the normal type-Ic supernova 1990aa
(cf. IAUC 5087, 5111; Matheson et al. 2001, A.J. 121, 1648), while the
broad feature centered on 630 nm resembles the Si II bump seen in spectra
of the broad-line type-Ic supernova 1998bw (associated with GRB 980425;
cf. IAUC 6895, 6901; Patat et al. 2001, Ap.J. 555, 900) around maximum
light (roughly three weeks after the gamma-ray-burst detection).
     Blondin et al. add that their spectrum is not consistent with the
description given by Soderberg et al. in GCN 1765, who report on a "smooth,
featureless continuum" with "some suggestion of a broad bump near 5500
Angstroms".  However, based on other spectra of familiar objects fully
reduced from the same night, Blondin et al. are confident that their flux
and wavelength calibrations are accurate.  The separation in time between
the MMT spectrum and the one described in GCN 1765 is only 0.1 day.
Blondin et al. clearly detect narrow emission lines at the supernova
position, consistent with the NED redshift of 1934 km/s for NGC 2770 (from
The Updated Zwicky Catalog, http://tdc-www.harvard.edu/uzc/).  Adopting
this recession velocity, the maximum absorption in the Si II line (rest
635.5 nm) is blueshifted by roughly 23000 km/s.  Also, interstellar Na I D
absorption at that redshift is visible in the spectrum with an equivalent
width of 0.2 nm.  A comparison plot can be seen at the following URL:
http://www.cfa.harvard.edu/supernova/spectra/sn2008D_comp.gif; note that,
in this plot, the spectrum of SN 1990aa had to be blueshifted by 5500 km/s
in order for prominent spectroscopic features to match up with those
present in SN 2008D, while that of SN 1998bw has been redshifted by 13000
km/s for the same reason.

     S. Valenti, Universita di Ferrara; D. Fugazza and E. Maiorano, Istituto
Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Bologna; V.
D'Elia and L. A. Antonelli, INAF, Ossevatorio Astronomico di Roma; S. Covino,
INAF, Osservatorio Astronomico di Brera; A. Magazzu and N. Pinilla-Alonso,
INAF, Telescopio Nazionele Galileo (TNG); M. Della Valle, INAF, Osservatorio
Astrofisico di Arcetri; G. Chincarini, Universita' degli Studi di Milano
Bicocca; E. Pian and P. A. Mazzali, INAF, Osservatorio Astronomico di Trieste;
and A. Harutyunyan and S. Benetti, INAF, Osservatorio Astronomico di Padova,
report that preliminary reduction of a spectrogram of 2008D, taken with the
TNG (+ LRS; range 350-780 nm) on Jan. 11.1 UT, shows that the spectrum
resembles that of the energetic type-Ic supernova 2006aj (cf. IAUC 8674) at
three days after explosion (Pian et al. 2006, Nature 442, 1011).  The Si II
635.5-nm feature shows a higher expansion velocity than in the spectrum of
2006aj.  The bluer bumps seen in the 2006aj spectrum, centered at about 440
and 500 nm, are not yet well developed, also suggesting a higher expansion
velocity.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 January 11                  (CBET 1205)              Daniel W. E. Green

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7173
SUBJECT: Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
DATE:    08/01/12 00:12:13 GMT
FROM:    Maryam Modjaz at UC Berkeley  <mmodjaz@astro.berkeley.edu>

 S. Blondin (Harvard-Smithsonian Center for Astrophysics, CfA), on behalf            
of the CfA Supernova Group; T. Matheson (National Optical Astronomy                  
Observatory); and M. Modjaz (University of California at Berkeley),                  
report:

A spectrum (range 320-840 nm) of 2008D (cf. CBET 1202), obtained on Jan.  
11.41 UT by P. Berlind with the MMT 6.5-m telescope (+ Blue Channel 
spectrograph), shows it most likely to be a peculiar type-Ic supernova in 
its early phases, confirming and refining earlier results (Malesani et al, 
GCN 7169; Valenti et al, GCN 7171).  The spectrum consists of a relatively 
blue continuum, with P-Cyg profiles (FWHM of approximately 10000 km/s) 
that are characteristic of a supernova spectrum blueward of 550 nm, and an 
extremely broad bump peaking at approximately 630 nm (with an associated 
absorption at 590 nm) that is similar to the Si II line (rest 635.5 nm)  
seen in the spectra of broad-line type-Ic supernovae around maximum light.  
More specifically, the double-absorption feature centered on 420 nm 
resembles that seen in the earliest spectrum of the normal type-Ic 
supernova 1990aa (cf. IAUC 5087, 5111; Matheson et al. 2001, A.J. 121, 
1648), while the broad feature centered on 630 nm resembles the Si II bump 
seen in spectra of the broad-line type-Ic supernova 1998bw (associated 
with GRB 980425; cf. IAUC 6895, 6901; Patat et al. 2001, Ap.J. 555, 900)  
around maximum light (roughly three weeks after the gamma-ray-burst 
detection).

     Blondin et al. add that their spectrum is not consistent with the               
description given by Soderberg et al. in GCN 1765, who report on a                   
"smooth, featureless continuum" with "some suggestion of a broad bump near           
5500 Angstroms".  However, based on other spectra of familiar objects                
fully reduced from the same night, Blondin et al. are confident that their           
flux and wavelength calibrations are accurate.  The separation in time               
between the MMT spectrum and the one described in GCN 1765 is only 0.1               
day. Blondin et al. clearly detect narrow emission lines at the supernova            
position, consistent with the NED redshift of 1934 km/s for NGC 2770 (from           
The Updated Zwicky Catalog, http://tdc-www.harvard.edu/uzc/).  Adopting              
this recession velocity, the maximum absorption in the Si II line (rest              
635.5 nm) is blueshifted by roughly 23000 km/s.  Also, interstellar Na I D           
absorption at that redshift is visible in the spectrum with an equivalent            
width of 0.2 nm.  

A comparison plot can be seen at the following URL:  
http://www.cfa.harvard.edu/supernova/spectra/sn2008D_comp.gif; note that, 
in this plot, the spectrum of SN 1990aa had to be blueshifted by 5500 km/s 
in order for prominent spectroscopic features to match up with those 
present in SN 2008D, while that of SN 1998bw has been redshifted by 13000 
km/s for the same reason.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7174
SUBJECT: XRF 080109 in NGC2770: Detectable Superluminal Motion
DATE:    08/01/12 17:14:24 GMT
FROM:    Arnon Dar at Technion-Israel Inst. of Tech  <arnon@physics.technion.ac.il>

Shlomo Dado (Technion), Arnon Dar (Technion and CERN) and A. De Rujula (CERN) 
Report:

The source of XRF 080109 in NGC2770 (GCN 7159) may, for months or even 
years, be moving at a constant superluminal angular velocity of the order 
of ~ 10 mas / month , should XRF 080109 be an ordinary long GRB viewed 
off-axis (DDD2004). The Doppler factor, delta, the Lorentz factor, gamma, 
and the viewing angle, theta, for XRFs and GRBs are related by,
delta ~ 2 gamma / [ 1 + (gamma theta)^2 ].

For the average GRB gamma*theta ~ 1 and the isotropic energy is,
E_{iso} ~ 8 E52 erg. For GRBs and XRFs, E_{iso} scales with delta^3 (DD2004).
For XRF 080109, E_{iso} ~ E45 erg (GCN 7159) , resulting in delta ~ 2, and 
gamma*theta ~ 30, for a typical gamma ~ 500 to 1000. The angular velocity 
cited above is v/d, with v ~ gamma*delta*theta*c, and d = 27 Mpc.

Interpreted in the same way, GRB 980425 had delta ~ 20 and gamma*theta ~ 10.
Its X-ray plateau (which we attributed to the GRB's jetted source and 
NOT to SN1998bw, DDD2002,3,7) was flat for a few months, implying a 
constant gamma, delta and v for that period. For XRF 080109 this 
approximate result may be valid for ten times a longer period, the ratio 
of Doppler factors. For single-pulse events, this ratio is also an 
estimate of the ratio of pulse durations, ~ 50 s in the 1.5-10 keV X-ray 
band for GRB 980425, and ~ 500 s for XRF 080109. If XRF 080109 and
GRB  980425 are identical, but for distance and viewing angle, the prompt 
peak X-ray luminosity of GRB 980425 (Pian et al. 2000) can also be scaled
as in the above to predict 5 E42 erg/s in the Swift XRT band, in agreement
with the observed ~ 4 E52 erg/s (GCN 7159).

The energy flux of the X-ray plateau of XRF 080901 is expected to be 
suppressed relative to that of GRB 980425 by the ratio (10) of Doppler 
factors to the power 4.1 (DDD2007) and may be hard to detect, unless it is 
compensated by a large ISM density around SN2007D in NGC2770.

If the radio emission of the GRB980425/SN1998bw pair was dominated by the jet 
which produced its off-axis GRB (DDD2003), scaling the observed peak flux 
density at t ~ 10 days of GRB 980425 (F_p = 50 mJy at 3.5 cm, Kulkarni et al. 
1998) yields, for XRF 080109a in a similar environment, a rough estimate of a 
peak date at ~100 days and a 35-cm peak flux of ~1.4 mJy, which may be 
observable at this wavelenght and nearby ones. Radio observations could even 
resolve two separated radio sources, SN2008D and the moving source of XRF 
090109. It is also not excluded that there is more than one moving source.

DDD2002: A&A, 388, 1079 (2002)
DDD2003: A&A, 401, 243 (2003)
DDD2004: A&A, 422, 381 (2004)
DDD2007: arXiv0712.1527 (2007)
Kulkarni, S. R., et al. 1998, astro-ph/9807001
Pian, E., et al. 2000, ApJ, 536, 778

////////////////////////////////////////////////////////////////////////
ATEL #1358                                                           ATEL #1358

Title:          Optical Spectrum of the NGC 2770 Transient
Author:         J. R. Thorstensen (Dartmouth)
Queries:        John.Thorstensen@dartmouth.edu
Posted:         13 Jan 2008;  3:31  UT
Subjects:       Optical, X-ray, Novae, Supernovae, Transients

I have obtained a spectrum of the apparent optical counterpart of the
X-ray transient in NGC 2770 (ATel 1353, 1354, 1355, and 1356), using the
2.4-m Hiltner telescope at MDM Observatory on Kitt Peak. There were 5 exposures
of 10 minutes each, centered around 2008 January 12.32 UT.  The modular
spectrograph gave 3.5 Angstrom resolution from 4300 to 7500 A, with vignetting
toward the ends.  The spectrum shows a strong, smooth continuum.  The only
spectral features clearly detected are (a) sharp, Na D absorption, at cz
= 2100 km/s, with a combined equivalent width of about 1 Angstrom; and
(b) sharp H-alpha emission, also at 2100 km/s, with an emission EW of about
5 Angstrom.  The background shows strong emission at H-alpha from the galaxy,
and the H-alpha in the transient object's spectrum could be poorly subtracted
background.  The redshifts of the features are consistent with that of
NGC 2770 (listed as 1947 km/s in the NED), given that the source is located
toward the outskirts of the galaxy where the rotation should be large.
The spectrum does not offer a definitive answer as to what kind
of object this is, but the redshifted NaD absorption puts it at least as
distant as NGC 2770.  

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7175
SUBJECT: XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
DATE:    08/01/13 03:42:47 GMT
FROM:    Maryam Modjaz at UC Berkeley  <mmodjaz@astro.berkeley.edu>

M. Modjaz, J. S. Bloom, N. R. Butler, D. Starr (UC Berkeley), R. P. 
Kirshner, A. Friedman (Harvard/CfA) report on behalf of a larger 
collaboration:

"From our analysis of the Swift XRT data we find an explosion time for the 
start of XRB 080109 (Berger & Soderberg, GCN 7159; Kong & Marcone, ATEL 
1355) as viewed by Swift of:

      t_0 = 2008-01-09 13:32:49 UT (+/- 5 sec).

We observed the field of SN 2007uy (Nakano et al. IAUC 8908; Blondin et 
al. CBET 1191) with the 1.3m PAIRITEL on Mt. Hopkins on 2008-01-09 08:45 
UT, i.e. 4.5 hours before t_0. We started observing again on 2008-01-10 
06:23:06 UT, i.e. 17 hours after the burst and for the following nights.

The SN 2008D (Li & Filippenko, IAUC 1202; Soderberg et al., GCN 7165; 
Malesani et al., GCN 7169; Valenti et al., GCN 7171; Blondin et al., CBET 
1205, see also GCN 7160-7168) associated with XRB 080109 is clearly 
detected in mosaic-stacks of each ~1100-sec integration time. From 
preliminary reductions of multi-epoch observations on Jan 11 and Jan 12, 
using ~15-20 2MASS stars in the field for the zeropoint, we derive the 
following error-weighted aperture magnitudes:

Filter  midtime (UTC)           Magnitude       MagError
 J     2008-01-11 8.4           16.63           0.13
 H     2008-01-11 8.4           16.33           0.17
 K_s   2008-01-11 8.3           16.11           0.18

 J     2008-01-12 8.0           16.51           0.06
 H     2008-01-12 7.9           16.15           0.14
 K_s   2008-01-12 7.9           16.22           0.29

No strong variability is detected over those 2 nights but the source was 
clearly not visible at these magnitudes on Jan 9 UT. Further data 
reduction and observations are in progress.  SN 2007uy was measured to be
~1 mag brighter in the J, H, K_s filters on Jan 11 and 12 UT."

A comparison of the 9 Jan, 12 Jan and historical 2MASS imaging can be 
found at:"

       http://pairitel.org/2sne-fig4.tiff

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7176
SUBJECT: XRB 080109/SN 2008D: Early decline in brightness and change in colors
DATE:    08/01/13 10:41:38 GMT
FROM:    Weidong Li at UC Berkeley KAIT/LOSS  <weidong@astron.berkeley.edu>

Weidong Li, Ryan Chornock, Ryan J. Foley, Alexei V. Filippenko, 
Maryam Modjaz, Dovi Poznanski, and Joshua S. Bloom (UC Berkeley) 
report: 

We analyzed the Swift/UVOT images of XRB 080109/SN 2008D in the 
U, B, and V filters taken on Jan 11 and 12 UT. We constructed 
template images for the field from follow-up data taken for 
SN 2007uy, and attempted image subtraction to remove the heavy
galaxy contamination at the site of SN 2008D. We were able to
obtain clean subtracted images as demonstrated at
http://astro.berkeley.edu/~bait/sn2008d.uvot-sub.gif

Using the calibration and photometry recipe of the UVOT 
U, B, V filters as described by Li et al. (2006, PASP 118, 37), 
we obtained the following photometry for SN 2008D. We used
t_0 as determined by Modjaz et al. (GCN 7175). 

UT date       t(days)   Total exp. time       Mag and err 

Jan 11.569     2.0047      2771.32s           U = 18.65 +/- 0.04   
Jan 11.591     2.0265      2579.13s           B = 19.05 +/- 0.04   
Jan 11.585     2.0203      2349.89s           V = 18.38 +/- 0.05   

Jan 12.408     2.9434       730.82s           U = 19.02 +/- 0.07  
Jan 12.409     2.8443       668.02s           B = 19.34 +/- 0.07  
Jan 12.445     2.8802       605.26s           V = 18.56 +/- 0.08  

The SN is seen to decline in the U (by 0.37 mag), B (by 0.29 mag),
and V (by 0.18 mag) filters between t = 2.0-2.9 d after the XRB. 
As the SN declined faster in U than in V, it became progressively
redder during this period. 

Possible explanations for the decline in the brightness at such early 
times for SN 2008D in the context of a SN Ib/c include the following.
(a) The SN had a bright initial optical flash from shock breakout,
and is now declining due to adiabatic expansion, similar to what
was observed for SN 1999ex (Stritzinger et al. 2002, AJ 124, 2100).
If this is the case, the SN will brighten again when the energy
input from radioactive decay starts becoming visible.
(b) The object is still dominated by the afterglow emission
from the XRB, similar to SN 2003dh/GRB 030329. However, spectroscopy
by Malesani et al. (GCN 7169), Blondin et al. and Valenti et al. (CBET 
1205) indicate rather strong SN features with no prominent power-law 
continuum.
(c) The SN has a similar behavior to the peculiar SN 2005bf
(Folatelli et al. 2006, ApJ 641, 1039), with two broad peaks in 
the light curves. However, the first peak of SN 2005bf was reached
more than 20 d after its discovery, and SN 2008D may have a 
very early and sharp first peak at t < 2 d. 

[GCN OPS NOTE(14jan08): Per author's request, the Malesani reference
was added to the "(b)" paragraph.]

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7177
SUBJECT: XRF 080109 in NGC2770: NIR observations at TNG
DATE:    08/01/13 13:36:46 GMT
FROM:    Angelo Antonelli at Obs. Astro. di Roma  <a.antonelli@oa-roma.inaf.it>

L.A. Antonelli (INAF/OAR), S. Valenti (Universita'  di  Ferrara),  D. 
Fugazza (INAF/OABr), V. D'Elia (INAF/OAR), E. Maiorano (INAF/IASF Bo), 
A. Magazzu' and N. Pinilla-Alonso (INAF/TNG), report on behalf of the 
CIBO collaboration:

We imaged the field of the galaxy NGC 2770 with the Telescopio 
Nazionale Galileo (TNG) [La Palma (Canary Islands)] equipped with NICS 
in the J,H,K  bands. Observations were performed on 2008 Jan 11, 
starting at 05:04:25 UT  for a total exposure  time of about 360 s in 
each filter.

The source reported by Deng & Zhu (GCN 7160), Thoene et al. (GCN 7161) 
and D'Elia et al. (GCN7162), is clearly detected in all bands with the 
following magnitudes: J=16.60+-0.13, H=16.33+-0.12, K=16.09+-0.12 
extimated using the 2MASS catalogue.  TNG NIR measures are consistent
with those reported by Modjaz et al. (GCN 7175 ).

Further analysis is underway.

GCN OPS NOTE(15jan08):  Per author's request, the last sentence in the
second paragraph was added.]

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7178
SUBJECT: Discovery of Radio Emission from Transient in NGC 2770
DATE:    08/01/13 16:05:36 GMT
FROM:    Alicia Soderberg at Caltech  <ams@astro.caltech.edu>

A. Soderberg (Princeton) reports on behalf of a large collaboration:

"We observed the field of the NGC 2770 X-ray transient (Berger & 
Soderberg, GCN 7159) on Jan 13.3 UT with the Very Large Array.  Based on a 
comparison with our pre-explosion radio data (Soderberg, ATEL 1350) 
we report the discovery of a new radio source at position (J2000):

RA = 09:09:30.6506 +- 0.0008
Dec = +33:08:20.14 +- 0.01

which is consistent with the positions of the optical (Deng & Shu, GCN 
7160), UVOT (Kong et al. ATEL 1356; Immler et al. GCN 7168), and X-ray 
(Page et al. GCN 7170) counterparts.  We note that these radio data
provide the most accurate position for the transient and its associated 
Type Ibc supernova, SN 2008D (Malesani et al. GCN 7169).

The flux density of the unresolved source is 0.12 +- 0.02 mJy at 8.46 GHz.
At a distance of 27 Mpc, this measurement corresponds to a radio spectral 
luminosity of 10^26 erg/s/Hz, comparable to that of Type Ibc SNe 
2002ap (Berger, Kulkarni & Chevlier, ApJL, 2002) and 2007gr (Soderberg,
ATEL 1187) and a factor of 100 lower than that of sub-energetic GRBs 
980425 (Kulkarni et al. Nature, 1998) and 060218 (Soderberg et al.
Nature, 2006) at comparable epochs.

Radio observations are ongoing.

We thank the VLA scheduling officers for their continued support in this
monitoring campaign."

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7179
SUBJECT: Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
DATE:    08/01/13 20:56:48 GMT
FROM:    David Burrows at PSU/Swift  <dnburrows@gmail.com>

D. N. Burrows (PSU), J. Cummings (GSFC), H. Krimm (GSFC), N. Gehrels 
(GSFC), K. L. Page (U. Leicester), S. Barthelmy (GSFC), E. Berger 
(Princeton), A. Cucchiara (PSU), D. Fox (PSU), S. Immler (GSFC), P. 
T. O'Brien (U. Leicester), and A. M. Soderberg (Princeton) report on 
behalf of the Swift team:

We report on additional analysis of the initial Swift BAT data and 
continuing XRT observations of the X-ray transient in NGC 2770 
(Berger & Soderberg, GCN Circ. 7159), for which the optical 
counterpart (Deng & Zhu, GCN 7160)  has been spectroscopically 
identified as a Type Ibc supernova (SN2008D;  Malesani et al., GGN 
Circ. 7169).

Quite fortunately, this object was in the BAT field of view in the 
two previous Swift observations (of BZQ J0618+4620 beginning at 
13:04:12.33 and of SN2007ax beginning at 13:12:24.5 UT on 9 Jan 
2008).  The Swift timeline was:

Obs 1:
13:02:02.3: begin slewing to BZQ J0618+4620 (RA, Dec = 94.530, +46.359)
13:04:12.3: end slew, settled on target.  NGC 2770 in BAT field of 
view with 54% coding.
Obs 2:
13:12:02.3: begin slewing to SN2007ax (RA, Dec = 125.679, +22.556)
13:13:24.5: end slew, settled on target.  NGC 2770 in BAT field of 
view with ~90% coding
Obs 3:
13:32:02.3: begin slewing to SN2007uy in NGC 2770 (RA, Dec = 137.407, +33.126)
13:32:48.9: end slew, settled on target.  NGC 2770 in BAT field of 
view with 100% coding.

13:50:02.1: begin slewing to RX J0923.5+5745 (RA, Dec = 140.887, +57.794)

BAT did not trigger on a GRB during the observations of either BZQ 
J0618 or SN2007ax.  An examination of the data from the direction of 
NGC 2770 during those observations shows no sign of any emission from 
this source in the BAT energy range, with upper limits of 1.0e-7 
erg/cm2 during the BZQ observation (Obs 1) and 1.1e-7 erg/cm2 during 
the SN2007ax observation (Obs 2).  During the observation of SN2007uy 
in NGC 2770 (Obs 3), when the X-ray transient occurred in the XRT 
data, the BAT upper limit is 8.9e-8 erg/cm2.  These upper limits are 
for the band 15-150 keV, assuming a power law photon index of 
1.  Extrapolating the X-ray transient spectrum from Obs 3 (Page et 
al., GCN Circ. 7170) into the 15-150 keV band, the extrapolated 
fluence is 5.2e-8, below the BAT fluence limit for this time interval.

During the slews, XRT collected no data and BAT collected only count 
rates.   There is no sign of a GRB in the BAT field of view during 
the slews, based on count rates during those time intervals.

To summarize, there is no indication of a GRB in the BAT energy range 
(15-350 keV) during the 30 minutes before the X-ray transient is seen 
in the XRT data, or during the observation of SN2007uy, which lasted 
over 1000 s (i.e., coincident with the X-ray transient).  The BAT 
upper limits are consistent with the extrapolation of the spectrum of 
the X-ray transient into the 15-150 keV band.

The nature and onset time of the X-ray transient are not entirely 
clear.  The source was already quite bright (~2 count/s) in the XRT 
band (0.3-10 keV) when the first exposure was taken beginning at 
13:32:48.9 UT, after which it rose rapidly to a peak count rate of 
about 5 count/s for ~90 s before decaying rapidly (Page et al., GCN 
Circ. 7170).  We note that the estimate for T0 given by Modjaz et al. 
(GCN Circ. 7175) is therefore only a limit; an earlier T0 cannot be 
excluded due to the lack of prior X-ray data.  The X-ray transient 
lightcurve and hard-to-soft spectral evolution are consistent with 
either a prompt, broad XRF or an X-ray flare (this event is similar 
to the giant X-ray flare in GRB 050502B); if interpreted as a flare, 
T0 could be hundreds of seconds earlier.

XRT observations are continuing.  Analysis of the late XRT data 
(after the first orbit) is complicated by the presence of a nearby 
weak source that contaminates the late-time data from the 
transient.  Our analysis, using a very small source extraction region 
to reduce the contamination from this nearby source, suggests that 
the late-time light curve has a shallow decay reminiscent of the 
plateau phase often seen in GRB X-ray afterglows, but lasting much 
longer than is typical for GRB afterglows (up to at least 200 ks 
after the first XRT detection).  The late-time decay index is -0.67 
+0.29/-0.33.

The X-ray transient peak could be the onset of an XRF, or it could be 
an X-ray flare in an XRF that began somewhat earlier.  The lack of an 
associated GRB in the BAT data suggests that there may be no GRB 
associated with this event (either due to a lack of ultrarelativistic 
ejecta or because it is not beamed towards us), in which case the 
X-ray transient could be related to shock breakout.  Alternatively 
this could indeed be a weak XRF with an unusually soft spectrum 
(Berger & Soderberg, GCN Circ. 7159).

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7180
SUBJECT: Gemini-South observations of XRF 080109 / SN 2008D
DATE:    08/01/14 05:14:31 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley and J. S. Bloom report on behalf of the GRAASP collaboration:

Using Gemini-South (+GMOS), we obtained 2x60 seconds of imaging in g and 
and 1x60 seconds in r of NGC 2770 as acquisition images in preparation 
for later spectroscopic observations.  The sequence started at UT 05:33 
2008-01-11, 40.00 hours after the trigger time derived by Modjaz et al. 
(GCN 7175). Calibrating relative to the Sloan Digital Sky Survey, we 
measure the following magnitudes for XRF 080109 / SN 2008D (Berger & 
Soderberg, GCN 7159; Kong & Marcone, ATEL 1355) at this time:

g = 18.72 +/- 0.15
r = 18.10 +/- 0.07

For SN 2007uy, we derive g = 16.31 +/- 0.15, r = 15.86 +/- 0.07.

An image of the field has been posted to:

http://lyra.berkeley.edu/~dperley/sn2008d/ngc2770_2sne.png

We thank E. R. Carrasco at Gemini Observatory for his assistance.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7181
SUBJECT: XRF 080109/SN 2008D: PROMPT Optical Imaging
DATE:    08/01/14 21:52:37 GMT
FROM:    Melissa Nysewander at STScI  <mnysewan@stsci.edu>

M. Nysewander (STScI), D. Reichart, K. Ivarsen, J.A. Crain, A. LaCluyze (UNC) report:


We observed the optical transient of XRF 080109/SN 2008D in NGC
2770 (Berger & Soderberg, GCN 7159; Deng & Zhu, 7160) on
January 12 & 13 with two PROMPT telescopes.  Observations were
taken under good conditions, but at high airmass.


On both nights, the P5 telescope took continuous 60s R-band
exposures for ~3 hrs, while P4 cycled through repeated sequences of
15x60s in BVI for a total of ~1 hr in each filter.   
Assuming the star at RA: 09:09:37.28 Dec: +33:09:35.1 (to be
consistent with D'Elia et al. GCN 7162) to have B=17.25, V=16.71,
R=17.20, and I=16.67 (NOMAD and USNOB), we find the following
preliminary magnitudes for the OT at Jan 12.3 and 13.3:


Filter:   Exposure:  Mag1:   Mag2:


B         12 x 60s   18.6    18.3

V         5 x 60s    17.9    17.7

R         5 x 60s    18.0    18.0

I         5 x 60s    17.2    17.1



These values may suggest a slight brightening over the two nights, but are consistent with no variation. 


Observations are ongoing.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7182
SUBJECT: optical observations, XRT in NGC 2770
DATE:    08/01/15 13:54:47 GMT
FROM:    Bill Peterson at U of Iowa/Dept Phys Astro  <albedozero@gmail.com>

B. Peterson, T. Jaeger, R. Mutel

Optical observations were made of the transient X-ray source in NGC 2270 (cfr. GCN 
7159) on 11, 12 and 14 Jan. using the 37cm "Rigel" telescope based in southern 
Arizona.  We used GSC 2495:1420 as a reference for differential photometry, 
assigning it a nominal magnitude of 14.3.
We plan further monitoring observations including short photometric scans of 
Tycho-2 stars in the field, allowing true magnitudes of the transient to be 
determined.

unfiltered      SN2007uy        XRT
2008/1/11       15.897 +/-0.005 17.919 +/-0.015
2008/1/12       15.825 +/-0.005 17.934 +/-0.017
2008/1/14       15.779 +/-0.005 18.041 +/-0.019

B filter
2008/1/11       15.989 +/-0.021 <19
2008/1/12       15.984 +/-0.012 18.030 +/-0.045
2008/1/14       15.912 +/-0.014 18.134 +/-0.059

V filter
2008/1/11       15.725 +/-0.010 18.320 +/-0.049
2008/1/12       15.684 +/-0.010 18.407 +/-0.054
2008/1/14       15.577 +/-0.010 18.344 +/-0.062

R filter
2008/1/11       15.830 +/-0.010 17.882 +/-0.034
2008/1/12       15.770 +/-0.010 18.245 +/-0.046

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7183
SUBJECT: XRF 080109 / SN 2008D: UKIRT JHK imaging
DATE:    08/01/15 15:31:45 GMT
FROM:    Nial Tanvir at IofA U.Cambridge  <nrt@ast.cam.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick),
A. Adamson and C. Davis (JACH) report on behalf of a larger collaboration:

We observed the field of XRF080109/SN2008D (GCN7159, GCN7160, GCN7169)
with UKIRT/UFTI on 2008-01-12 (13 UT) and on 2008-01-15 (14 UT) in
good conditions, using the JHK filters on each occasion.  Between the
two epochs we estimate that the optical transient brightened by
approximately 0.35+/-0.05 mag in each band, confirming the onset of a
slowly rising supernova component.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7184
SUBJECT: XRF 080109 / SN 2008D: spectroscopic evolution
DATE:    08/01/15 17:45:10 GMT
FROM:    Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center  <malesani@astro.ku.dk>

D. Malesani (DARK), J. Sollerman (DARK and Univ. Stockolm), J.P.U. 
Fynbo, C.C. Thoene, D. Xu, J. Hjorth, G. Leloudas, P.M. Vreeswijk, D.J. 
Watson (DARK), P. Jakobsson (Univ. Herfordshire), T. Augusteijn, C. 
Villforth, S.-M. Niemi (NOT), report on behalf of a larger collaboration:

We observed SN 2008D with the Nordic Optical Telescope on Jan 13.05 and 
Jan 15.16 UT. Spectra were acquired covering the range 3700-7500 AA.

The spectra have evolved when compared to earlier epochs (Malesani et 
al., GCN 7169; Blondin et al., CBET 1205; Valenti et al., CBET 1205). 
The spectrum of Jan 15 now appears similar to that of the normal type-Ic 
SN 1994I a few days before maximum (Clocchiatti et al. 1996, ApJ, 462, 
462). In particular, the spectral features are clearly narrower than 
those of SN 1998bw and SN 2006aj at comparable epochs.

A plot of the NOT spectrum of Jan 15, compared with that of SN 1994I 
dereddened by A_V = 0.7 mag, is shown at the following URL:

http://www.astro.ku.dk/~malesani/GRB/080109/spec_Jan15.png

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7185
SUBJECT: Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
DATE:    08/01/15 18:08:04 GMT
FROM:    Stefan Immler at NASA/GSFC  <immler@milkyway.gsfc.nasa.gov>

S. Immler (NASA/UMCP/GSFC) reports on behalf of the Swift team:

Regular Swift UVOT monitoring of the optical counterpart to the X-ray
transient in NGC 2770, SN 2008D (Atel 1353), shows a brightening in
the v and b filters by 0.4 mag and 0.2 mag, respectively, over a 3-day
period (2008-01-13 01:24:08 UT to 2008-01-15 01:25:19 UT).
This rise confirms the onset of a supernova component (GCN 7183).
The following magnitudes are measured for observations starting on
2008-01-15 01:26:24 UT:

v = 18.3+/-0.1 (496 s exposure time),
b = 19.1+/-0.1 (496 s)
u = 19.6+/-0.2 (496 s),
uvw1 > 20.5 (3-sigma upper limit, 989 s),
uvm2 > 20.3 (3-sigma upper limit, 1247 s), and
uvw2 > 20.9 (3-sigma upper limit, 1983 s).

We further observe a decline of the optical counterpart in the v, b, and
u filters by 0.1 mag, 0.4 mag, and 0.6 mag, respectively, prior to the
rise (2008-01-11 02:40:44 UT to 2008-01-13 01:12:58 UT).

These magnitudes are on the UVOT photometric system (see Poole et al.,
2007, MNRAS, 383, 627) which in the optical is close to the Johnson
UBV system. They have not been corrected for Galactic extinction of
E(B-V) = 0.023 mag (Schlegel et al. 1998, ApJ 500, 525).

A full report on the complete Swift BAT, XRT, and UVOT data will be
released shortly.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7186
SUBJECT: NGC 2770B has the same redshift as NGC 2770
DATE:    08/01/15 22:42:35 GMT
FROM:    Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center  <malesani@astro.ku.dk>

Johan P.U. Fynbo, Daniele Malesani (DARK), Thomas Augusteijn, and 
Sami-Matias Niemi (NOT), report:

We acquired a spectrum of the galaxy (or galaxy pair) NGC 2770B, located 
~3 arcmin West of NGC 2770, the host galaxy of XRF 080109 / SN 2008D 
(Berger & Soderberg, ATel 1353; Deng & Zhu, GCN 7160). Observations were 
carried out with the Nordic Optical Telescope, starting on 2007 Jan 
15.213 UT, for a total exposure time of 10 min.

 From the detection of prominent nebular lines, including Balmer 
features, [OII], [OIII], [SII], [NII] and others, we determine the 
redshift to be z = 0.0064 +- 0.0003. This is very similar to the 
redshift of NGC 2770 (z=0.0065 according to NED). At the corresponding 
distance (25.7 Mpc), the angular separation of ~3 arcmin corresponds to 
only 22 kpc in projection.

Similarly to NGC 2770, NGC 2770B is undergoing intense star formation, 
as implied by its blue colors and the large Halpha equivalent width. 
Although there is not much evidence for morphological distorsions, a 
past interaction might have triggered the strong starburst activity in 
both objects.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7183
SUBJECT: XRF 080109 / SN 2008D: UKIRT JHK imaging
DATE:    08/01/15 15:31:45 GMT
FROM:    Nial Tanvir at IofA U.Cambridge  <nrt@ast.cam.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick),
A. Adamson and C. Davis (JACH) report on behalf of a larger collaboration:

We observed the field of XRF080109/SN2008D (GCN7159, GCN7160, GCN7169)
with UKIRT/UFTI on 2008-01-12 (13 UT) and on 2008-01-15 (14 UT) in
good conditions, using the JHK filters on each occasion.  Between the
two epochs we estimate that the optical transient brightened by
approximately 0.35+/-0.05 mag in each band, confirming the onset of a
slowly rising supernova component.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7184
SUBJECT: XRF 080109 / SN 2008D: spectroscopic evolution
DATE:    08/01/15 17:45:10 GMT
FROM:    Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center  <malesani@astro.ku.dk>

D. Malesani (DARK), J. Sollerman (DARK and Univ. Stockolm), J.P.U. 
Fynbo, C.C. Thoene, D. Xu, J. Hjorth, G. Leloudas, P.M. Vreeswijk, D.J. 
Watson (DARK), P. Jakobsson (Univ. Herfordshire), T. Augusteijn, C. 
Villforth, S.-M. Niemi (NOT), report on behalf of a larger collaboration:

We observed SN 2008D with the Nordic Optical Telescope on Jan 13.05 and 
Jan 15.16 UT. Spectra were acquired covering the range 3700-7500 AA.

The spectra have evolved when compared to earlier epochs (Malesani et 
al., GCN 7169; Blondin et al., CBET 1205; Valenti et al., CBET 1205). 
The spectrum of Jan 15 now appears similar to that of the normal type-Ic 
SN 1994I a few days before maximum (Clocchiatti et al. 1996, ApJ, 462, 
462). In particular, the spectral features are clearly narrower than 
those of SN 1998bw and SN 2006aj at comparable epochs.

A plot of the NOT spectrum of Jan 15, compared with that of SN 1994I 
dereddened by A_V = 0.7 mag, is shown at the following URL:

http://www.astro.ku.dk/~malesani/GRB/080109/spec_Jan15.png

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7187
SUBJECT: XRF 080109 / SN 2008D: optical observations
DATE:    08/01/16 01:23:04 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Pavlenko, A. Litvinchova, Yu. Efimov (CrAO),   A. Pozanenko (IKI) report
on behalf of a larger collaboration:

We observed the optical transient of XRF 080109/SN 2008D in NGC 2770
(Berger,  Soderberg, GCN 7159; Deng, Zhu, GCN 7160) on January 11,12,13 with
CrAO 2.6 telescope  (ZTSh).  On Jan. 11 observations were completed in BVRI
and on Jan. 12-13 in BR filters under good weather conditions.

Preliminary photometry of the transient XRF 080109/SN 2008D obtained after
galaxy subtracion and assuming  reference stars from USNO-A2.0
1200-06240802,  R=17.3, B=17.7 (the same star used in GCN 7162 (D'Elia et
al)):

Mid time (UT), Filter, magnutude

Jan. 12.04 B 18.63
Jan. 12.04 R 17.98
Jan. 13.01 B 18.74
Jan. 12.99 R 18.04
Jan. 13.93 B 18.84
Jan. 14.01 R 17.98

Typical statistical uncertainties of magnitude in the table above is better
than 0.01.  Magnitudes are not corrected for Galaxy reddening.

Within our observations  B magnitude is fading  on Jan. 11-13, while the R
brightness has a minimum on the night on Jan. 12/13.  Color (B-R) gradually
increasing from 0.65 (Jan. 12) to 0.86 (Jan. 14) which aslo may support of
SN dominance in light  curve of the transient (Malesani et al. GCN 7184).

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7188
SUBJECT: Transient 080109/ SN 2008D, IR Spectrum
DATE:    08/01/16 20:14:54 GMT
FROM:    Peter Garnavich at U of Notre Dame  <pgarnavi@nd.edu>

H. Marion (U. Texas/Texas State), P. Garnavich (Notre Dame)
and C. Gerardy (FSU) report:

We obtained near-infrared spectra of supernova 2008D (ATEL 1353; GCN
7160) with the NASA Infrared Telescope Facility (IRTF) and
SPEX instrument. The data were taken January 14.4 UT and cover
the wavelength range 0.7 to 2.5 microns. A preliminary reduction
of the spectrum shows a strong absorption feature at 1.01 micron.
This feature is seen in several other type Ic events (e.g. SN 1994I,
Millard et al. 1999, ApJ, 527, 746; SN2002ap, Motohara et al.
2002, IAUC 7834) and is probably a combination of HeI, CI and SiI.
A weaker feature at 0.80 micron is likely to be CaII (0.858 micron)
with an absorption minimum at 21000 km/s.

We thank Alan Tokunaga for coordinating these observations at the IRTF.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7189
SUBJECT: Transient 080109/ SN 2008D, metallicity of the host galaxy
DATE:    08/01/16 20:39:34 GMT
FROM:    Krzysztof Z. Stanek at CfA  <kstanek@cfa.harvard.edu>

J. L. Prieto (Ohio State) reports:

The host galaxy of SN 2008D, NGC 2770, is included in the latest version
of our catalog of supernova hosts:

http://www.astronomy.ohio-state.edu/~prieto/snhosts/sort_name.html#2008D

The central oxygen abundance of NGC 2770, as measured by Tremonti et al.
(2004, ApJ, 613, 898) using nebular emission lines, is 12 + log(O/H) = 9.0
and its absolute magnitude is MB = -20.7 (HyperLeda catalog), putting this
Sc galaxy on the luminosity-metallicity relationship of star forming
galaxies (e.g., Tremonti et al. 2004). These characteristics are typical
of the hosts of other type Ib/c supernovae (Prieto, Stanek & Beacom 2008,
ApJ, in press, arXiv: 0707.0690), and in contrast with the low-metallicity
of the hosts of long-GRBs with supernovae (e.g., Stanek et al. 2006, AcA,
56, 333). We note, however, that SN 2008D exploded fairly far from the
center of NGC2770 (galactocentric distance of ~10kpc), which may have a
strong metallicity gradient, as suggested by its late-type Sc
classification. From the measured radial metallicity gradients of galaxies
with similar morphological class (Zaritsky, Kennicutt, & Huchra 1994, ApJ,
420, 87), we estimate an oxygen abundance of 8.4 < 12 + log(O/H) < 8.8 (in
the scale of Tremonti et al.) at the site of the supernova explosion. Even
though this is only an approximation, this value is consistent with the
metallicities measured at the sites of broad-lined SN Ic without GRBs
(Modjaz et al. 2008, AJ, in press, astro-ph/0701246).

Indepently of the true nature of the X-ray transient associated with the
peculiar type Ic supernova 2008D (e.g., Blondin et al., CBET 1205), an XRF
or shock breakout (Burrows et al., GCN Circ. 7179), its remarkable
star-forming host, NGC 2770, deserves to be studied in detail: it has
produced three supernovae of type Ib/c in less than 10 years (SN 1999eh,
2007uy, and 2008D), which most likely result from death of very massive
stars (mass > 30 Msun, e.g., Heger et al. 2003, ApJ, 591, 288).

This message may be cited.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7190
SUBJECT: XRF 080109 / SN 2008D: WSRT Radio Detection
DATE:    08/01/17 01:18:54 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst, C. Kouveliotou (NASA/MSFC), R.A.M.J. Wijers and
A. Kamble (Univ. of Amsterdam) report on behalf of a larger collaboration:

"We observed the position of the NGC 2770 transient (GCN 7159) at 4.9 GHz
with the Westerbork Synthesis Radio Telescope at January 15 19.38 UT to
January 16 7.06 UT.
We detect a source with a flux density of 369 +/- 33 microJy at the
position of the radio counterpart reported at 8.46 GHz (GCN 7178).

We would like to thank the WSRT staff for scheduling and obtaining these
observations."

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7191
SUBJECT: Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
DATE:    08/01/17 14:03:53 GMT
FROM:    Lokesh Kumar Dewangan at Phys Res Lab, Ahmedabad,India  <lokeshd@prl.res.in>

      Lokesh, V. Venkat, R. Purohit, J. Jain, S. Vadawale and B.G. Anandarao
      Physical Research Laboratory, Ahmedabad, India.

   We made infrared photometry at Mt. Abu 1.2 m Cassegrain telescope using
NICMOS camera on the Transient XRF 080109/SN 2008D in NGC 2770 (Berger &
Soderberg, GCN 7159; Modjaz et al., GCN 7175 and Antonelli et al., GCN
7177) during 2008 Jan 11, Jan 13 and Jan 15. Sky conditions were good
during the first two nights but not so much on the third. The calibration
was made on the two bright stars in the field of view against 2MASS values
for 08-01-11 and using the photometric standard AS 20-0 for the other
nights.  The filters used (and overall integration times), magnitudes with
errors are given below for each date (UT).

  Date (UT)         Filter         Magnitude
2008-01-11.892    J (360 sec)     16.71+/-0.12
2008-01-13.894    J (360 sec)     16.57+/-0.10
2008-01-13.979    H (360 sec)     15.87+/-0.10
2008-01-15.864    J (480 sec)     16.12+/-0.20
2008-01-15.092    H (480 sec)     16.02+/-0.22

These magnitudes are consistent with GCN 7175 and GCN 7177. We continue to
monitor this source in the JH bands.

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7192
SUBJECT: Transient in NGC2770 / SN2008D: Metallicity of nearby HII regions 
DATE:    08/01/17 15:27:09 GMT
FROM:    Edo Berger at Princton U  <eberger@astro.princeton.edu>

E. Berger and A. M. Soderberg (Princeton) report on behalf of a larger 
collaboration:

"We used the ARC 3.5-m telescope at Apache Point Observatory to obtain 
spectroscopic observations of the X-ray transient in NGC2770 (GCN 7159). 
We obtained 4x1200 sec exposures with the DIS red+blue cameras providing a 
wavelength range of 3600-9000A.  The spectra therefore cover a wide range 
of nebular emission lines relevant for metallicity measurements (i.e. 
[OII], H-beta, [OIII], H-alpha, [NII], and [SII]).  Following the 
prescriptions of Kewley & Dopita (2002) we use several indicators (e.g. 
[NII]/[OII], R23) to measure the metallicity and ionization parameter of 
bright HII regions within +/-8 arcsec (about 1 kpc) of the X-ray transient 
position.  We find metallicities of 12+log(O/H)=8.9+/-0.2, or about 
0.6-1.6 times the solar metallicity.  The error bar includes both the 
spread in metallicity and the systematic uncertainty between the various 
indicators.  This value is higher, and more robust, than the estimate in 
GCN 7189 which relied on an assumed metallicity gradient."

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7193
SUBJECT: XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
DATE:    08/01/20 01:47:20 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst, C. Kouveliotou (NASA/MSFC) and A. Kamble (University
of Amsterdam) report on behalf of a larger collaboration:

"We observed the position of the NGC 2770 transient (GCN 7159) at 1.4 GHz
with the Westerbork Synthesis Radio Telescope at January 18 19.30 UT to
January 19 6.86 UT.
The galaxy NGC 2770 is resolved and the flux density of the galaxy core is
~4.4 mJy. The flux at the position of XRF 080109 / SN 2008D (GCN 7178) is
~1.1 mJy. There is no significant detection of a point source at this
position.
The one-sigma rms noise in the map is 48 microJy per beam.

We would like to thank the WSRT staff for scheduling and obtaining these
observations."

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7206
SUBJECT: X-ray transient in NGC 2770: RTT150 optical observations
DATE:    08/01/23 14:55:26 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

I. Bikmaev, A. Galeev, N. Sakhibullin (KSU/AST)
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Khamitov, Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)

report:

The optical counterpart to X-ray transient in NGC 2770, SN2008D (GCN
Rep. 110.1, GCN Circ. 7160, 7161) was observed also with Russian-Turkish
1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey)
during the first two nights after the XRF.

Series of BVRI direct images and low resolution spectra (during the second
night) were taken.

The object shows no variability during the few hours of observations in
every nignt at the level >~ 0.05m, but we detect the decline of the OT in
all filters betwen two nights. Assuming R=17.3 and B=17.7 magnitudes for
USNO-A2.0 1200-06240802 star (as it was done in GCN's 7162 and 7187), we
estimate the following magnitudes for the transient:

Time, UT    t-t0,days   mag

Jan 11.03   0.46        R = 18.06
Jan 11.14   0.57        B = 18.72     
Jan 12.11   1.55        R = 18.15   
Jan 12.12   1.55        B = 18.98

However, these measurements are preliminary, more accurate subtraction of
the galaxy is to be done.

A low resolution spectrum was obtained, using TFOSC spectrometer. We take
3x1200s exposures, centered at Jan 12.00 UT. The spectrum has resolution
about 15~A, covering 3900 to 9000~A. Strong H_alpha and other narrow
emission lines are detected in the galaxy near the object, so that it was
difficult to correctly subtract background near these lines. Hovewer, we
believe, that the overall shape of our spectrum is correct. We definitely
see much less amount of supernova signatures as compared to Blondin et
al. (GCN 7173), in agreement with Soderberg et al. (GCN 7165) and
Thorstensen (ATEL #1358).

The finding chart and the plot of our spectrum can be found at:

http://hea.iki.rssi.ru/grb/080110-SN2008D/indexeng.html

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7212
SUBJECT: Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
DATE:    08/01/24 01:08:45 GMT
FROM:    Maryam Modjaz at UC Berkeley  <mmodjaz@astro.berkeley.edu>

M. Modjaz, R. Chornock, R. J. Foley, A. V. Filippenko, and W. Li (UC
Berkeley); and G. Stringfellow (U of Colorado) report on behalf of a
larger collaboration:

"We obtained optical spectra of SN 2008D (Li & Filippenko, CBET 1202;
Soderberg et al., GCN 7165; Malesani et al., GCN 7169; Valenti et al.,
GCN 7171; Blondin et al., CBET 1205, see also GCN 7160-7168). 
A spectrum (range 350-970 nm) taken on Jan 21.22 UT with the ARC
3.5-m telescope (+ DIS) at APO shows it to be a type-Ib supernova.
The fully reduced spectrum shows the development of conspicuous lines
of He I (rest 447.1, 587.6, 667.8, 706.5 nm) with the maximum absorptions
blueshifted by roughly 10,000-11,000 km/s (assuming a recession velocity
for the host galaxy of 1947 km/s). 

This spectrum, when de-reddened by A_V ~ 2 mag, is very similar to
spectra of SN Ib 2005hg (CBET 271; Modjaz et al., in prep), about 1
week before maximum. Cross-correlation with a library of supernova
spectra using the "Supernova Identification" code (SNID; Blondin and
Tonry 2007, Ap.J. 666, 1024) indicates that the spectrum of SN 2008D
is also similar to that of SN Ib 1998dt (Matheson et al. 2001,
A.J. 121, 1648) at maximum light. We furthermore detect strong
absorption at 615 nm which could be due to Si II (rest 635.5 nm) at
10,000 km/s or alternatively, very high-velocity H-alpha at 19,000
km/s. SN 2008D is the SN associated with the X-Ray Transient 080109
(Berger & Soderberg, GCN 7159; Kong & Marcone, ATEL 1355) and was
previously classified as peculiar type-Ic supernova (Blondin et al.,
Valenti et al. CBET 1205) based on very early spectra, and later as a
normal type-Ic SN (Malesani et al. GCN 7184) with possibly some He as
seen in NIR spectra (Marion et al. GCN 7188)."

////////////////////////////////////////////////////////////////////////
                                                  Electronic Telegram No. 1221
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVA 2008D IN NGC 2770
     M. Modjaz, R. Chornock, R. J. Foley, A. V. Filippenko, and W. Li,
University of California at Berkeley; and G. Stringfellow, University of
Colorado, report that a spectrum (range 350-970 nm) taken of SN 2008D (cf.
CBETs 1202, 1205), obtained by Stringfellow on Jan. 21.22 UT with the
Astrophysical Research Consortium 3.5-m telescope (+ DIS) at Apache Point
Observatory, shows it to be a type-Ib supernova.  The fully reduced
spectrum shows the development of conspicuous lines of He I (rest 447.1,
587.6, 667.8, and 706.5 nm), with the maximum absorptions blueshifted by
roughly 10000-11000 km/s (assuming a recession velocity for the host galaxy
of 1947 km/s).  This spectrum, when de-reddened by an A_V value of about 2
mag, is very similar to spectra of the type-Ib supernova 2005hg (cf. CBET
271; Modjaz et al., in preparation), about 1 week before maximum.  Cross-
correlation with a library of supernova spectra using the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024)
indicates that the spectrum of SN 2008D is also similar to that of the
type-Ib supernova 1998dt (IAUCs 7006, 7011) at maximum light (Matheson et
al. 2001, A.J. 121, 1648).  Modjaz et al. furthermore detect strong absorption
at 615 nm that could be due to Si II (rest 635.5 nm) at 10000 km/s or,
alternatively, very-high-velocity H-alpha at 19000 km/s.  SN 2008D was
previously classified as a peculiar type-Ic supernova (GCN 7169; CBET 1205).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 January 24                  (CBET 1221)              Daniel W. E. Green

////////////////////////////////////////////////////////////////////////
nic Telegram No. 1222
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVA 2008D IN NGC 2770
     NOTE:  this replaces the text on CBET 1221:

     M. Modjaz, R. Chornock, R. J. Foley, A. V. Filippenko, and W. Li,
University of California at Berkeley; and G. Stringfellow, University of
Colorado, report that a spectrum (range 350-970 nm) taken of SN 2008D (cf.
CBETs 1202, 1205), obtained by Stringfellow on Jan. 21.22 UT with the
Astrophysical Research Consortium 3.5-m telescope (+ DIS) at Apache Point
Observatory, shows it to be a type-Ib supernova.  The fully reduced
spectrum shows the development of conspicuous lines of He I (rest 447.1,
587.6, 667.8, and 706.5 nm), with the maximum absorptions blueshifted by
roughly 10000-11000 km/s (assuming a recession velocity for the host galaxy
of 1947 km/s).  This spectrum, when de-reddened by an A_V value of about 2
mag, is very similar to spectra of the type-Ib supernova 2005hg (cf. CBET
271; Modjaz et al., in preparation), about 1 week before maximum.  Cross-
correlation with a library of supernova spectra using the "Supernova
Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024)
indicates that the spectrum of SN 2008D is also similar to that of the
type-Ib supernova 1998dt (IAUCs 7006, 7011) at maximum light (Matheson et
al. 2001, A.J. 121, 1648).  Modjaz et al. furthermore detect strong absorption
at 615 nm that could be due to Si II (rest 635.5 nm) at 10000 km/s or,
alternatively, very-high-velocity H-alpha at 19000 km/s.  SN 2008D was
previously classified as a type-Ib/c supernova (GCN 7169), a peculiar type-Ic
supernova (CBET 1205), and a normal type-Ic supernova (GCN 7184) with possibly
some He as seen in near-infrared spectra (GCN 7188).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 January 24                  (CBET 1222)              Daniel W. E. Green

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7216
SUBJECT: SNe 2008D and 2007uy: Chandra Detections
DATE:    08/01/25 13:58:13 GMT
FROM:    Dave Pooley at UW,Madison  <dave@astro.wisc.edu>

David Pooley and Alicia Soderberg report on behalf of a large collaboration:
the Chandra X-ray Observatory performed a 17.9 ks ACIS-S3 observation
of the field of SNe 2008D (associated with XRB 080109; Berger & Soderberg,
GCN 7159, ATEL #1353; Kong & Maccarone, ATEL #1355) and 2007uy
(Nakano et al., IAUC 8908) starting at 2008 Jan 19 20:41 UT.

In a 1'x1' box around SN 2008D, four X-ray sources are detected,
including SN 2008D at R.A. = 09:09:30.625, Decl. = +33:08:20.16 (J2000)
with an error circle of 0.19" radius, in agreement with the radio
(Soderberg, GCN 7178), optical (Deng & Shu, GCN 7160), and UVOT
(Kong et al., GCN 7170; Immler et al., GCN 7168) positions.
Ten counts are detected from 2008D in the 0.5--8 keV band,
the lowest at ~0.9 keV and the highest at ~3.2 keV.  Spectral analysis
was performed in Sherpa using Cash statistics with two models,
an absorbed power law (PL) and an absorbed thermal bremsstrahlung (TB).
The best-fit parameters are:

PL:  nH = 1.3(+1.0/-1.3)e22 cm^-2 ,   Photon Index = 3.6(+1.7/-1.4)
TB:  nH = 1.0(+0.7/-0.5)e22 cm^-2 ,   kT = 1.2(+1.9/-0.5) keV

The PL model gave an unabsorbed 0.5--8 keV flux of 2.8e-14 erg/cm^2/s,
and the TB gave 1.2e-14 erg/cm^2/s.

Fixing the column at 6e21 cm^-2 (Kong & Maccarone, ATEL 1355),
the best-fit PL photon index is 2.4(+0.7/-0.6) with an unabsorbed flux
of 0.9e-14 erg/cm^2/s, and the best-fit TB temperature is kT = 1.8(+2.3/-0.7) keV
with an unabsorbed flux of 0.8e-14 erg/cm^2/s.

At a distance of 27 Mpc, the X-ray luminosity of SN 2008D is 2e39 erg/s
at ~10 days after the X-ray burst.  This is at least a factor of 100 less luminous
than GRB afterglows on the same timescale, including sub-energetic bursts
similar to GRB-SNe 1998bw and 2006aj, but it is comparable to optically selected SNe Ibc.

A Kolmogorov-Smirnov analysis of the photon arrival times gives only a 3.1% chance
of being consistent with a constant count rate.  (Note: all of the above fluxes
are time-averaged over the 17.9 ks observation.)

The positions and spectral parameters of the three other sources (X1, X2, X3) are listed below.

Src RA (J2000)    Dec (J2000)  err   Cts  nH              Phot.Ind.       Fx
X1  09:09:31.800  +33:08:05.03 0.05  166  1.6(+0.9/-0.8)  1.4(+0.2/-0.2)  10.8
X2  09:09:31.215  +33:08:21.83 0.09   41  6.5(+3.3/-2.6)  2.5(+0.7/-0.6)   3.9
X3  09:09:30.686  +33:08:05.79 0.19   11  0.3(+3.2/-0.3)  1.1(+0.9/-0.5)   0.7

Notes: err is the radius of the position error circle in arcsec.  Cts is the number
of detected counts in the 0.5--8 keV band.  nH is in units of 10^21 cm^-2.
Phot.Ind. is the best-fit PL photon index.  Fx is the unabsorbed luminosity
in units of 10^-14 erg/cm^2/s.

These sources are within the PSF of the Swift XRT (and therefore contaminate
the Swift X-ray light-curve).

In addition, SN 2007uy and three other sources are detected in NGC 2770.
Their parameters are given below.

Src  RA (J2000)    Dec (J2000)  err   Cts  nH              Phot.Ind.       Fx
07uy 09:09:35.273  +33:07:09.09 0.36    5  0.2(+2.8/-0.2)  1.8(+1.2/-0.8)  0.2
X4   09:09:36.962  +33:06:33.97 0.27   12  4.6(+5.2/-1.8)  1.6(+1.0/-0.9)  1.0
X5   09:09:33.092  +33:07:18.83 0.28    7  4.1(+5.6/-4.1)  2.4(+1.5/-1.2)  0.5
X6   09:09:36.170  +33:07:08.12 0.33    6  0.2(+4.7/-0.2)  0.5(+1.0/-0.7)  0.6

The columns are the same as above.

The Chandra position of SN 2007uy is in agreement with the radio (Soderberg, ATEL #1350)
and optical (Nakano et al., IAUC 8908) positions.

None of the sources besides SN 2008D show evidence for short-term variability.

"True-color" images of the fields can be found at:
http://www.astro.wisc.edu/~pooley/sn2008d.png (60"x60")
http://www.astro.wisc.edu/~pooley/sn2007uy.png (80"x80")
(0.5--1.2 keV in red, 1.2--2.5 keV in green, 2.5--6 keV in blue)

A plot of the photon distribution of SN 2008D produced by ACIS Extract can be found at:
http://www.astro.wisc.edu/~pooley/sn2008d-photon_dist.png

[GCN OPS NOTE(25jan08): Per author's request, the "010809" string in the
first sentence was changed to "080109".  Line breaks were also added.]

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  7239
SUBJECT: X-ray transient in NGC 2770: RTT150 optical observations
DATE:    08/01/30 16:25:52 GMT
FROM:    Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>

I. Khamitov (TUG), I. Bikmaev, R. Gumerov,
A. Nemtinov, N. Sakhibullin (KSU/AST),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)

report:

We continued observations of the optical counterpart to X-ray transient in
NGC 2770, SN2008D (GCN Rep. 110.1, GCN Circ. 7160, 7161) with
Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National
Observatory, Turkey) in 26 (02:50-04:50UT), 27 (01:00-04:00UT), 28 
(04:05UT) Jan 2008 using ANDOR TE CCD (DW-436).

Series of BVRI direct images were taken on Jan 26 and 27, and also we made
300s R-exposure on Jan 28 under windy weather conditions (the seeing was
more then 2 arcsec for all observations).

The object shows no variability between the nignts at the level >~ 0.05mag.
In comparision with the our previous observations (11, 12 Jan, Bikmaev et
al., GCN7206) the OT is brighter approximatelly by 1.0 mag and 0.6 mag
in R and B bands respectively.

Assuming R=17.3 and B=17.7 magnitudes for USNO-A2.0 1200-06240802 star, we
estimate the following magnitudes for the transient:

Time, UT    t-t0,days   mag

Jan 26.14   16.58      R = 17.03
Jan 26.15   16.59      B = 18.06
Jan 27.09   17.53      B = 18.13
Jan 27.12   17.56      R = 17.01
Jan 28.17   18.61      R = 16.98

Also we found that in our previous circular there was a misprint in t-t0
column. The correct t-t0 values can be obtained by adding one day to the
values in that circular.