HDTenEightyP/NetNews huggingface dataset:
From: palmer@sfu.ca (Leigh Palmer)
Subject: Re: Distance of horizon
Organization: Simon Fraser University
Date: Thu, 19 Nov 1992 18:11:59 GMT

In article <ETHANB.92Nov19004023@ptolemy.astro.washington.edu>
ethanb@ptolemy.astro.washington.edu (Ethan Bradford) writes:
>In article <1992Nov19.021430.13833@sfu.ca> palmer@sfu.ca (Leigh Palmer)
writes:
>
>   In article <lglhj3INNb0c@appserv.Eng.Sun.COM>
fiddler@concertina.Eng.Sun.COM
>   (steve hix) writes:
>   >Anyone have handy a function for figuring the distance of the
>   >horizon from a viewer based on the viewer's height from the
>   >surface?
>                               -1
>   Try d = R arccos ( 1 + h/R )
>
>       d = horizon distance
>       h = height above MSL (assuming horizon is at sea level)
>       R = radius of Earth
>
>This is a complicated approximation to a simple function.  The exact
>answer is
>  d = sqrt(h^2 + 2 R h) \approx sqrt(2 R h)

I acknowledge that the solution I posted,

                                  -1
          d = R arccos ( 1 + h/R )

is a model solution. It is not an approximation nor is it complicated.

My solution holds exactly for a spherical Earth with no atmosphere, the best I
could do under the constraint of a five minute calculation, all I had at the
time to help the questioner out. Im sure he had no expectation that he would
get a topographically correct solution parametrized with barometric inputs; he
just wants a formula his kids can use (and plot, presumably). The one I gave
him is easily evaluated with a hand calculator in the form given, with the
provision that the calculator be in radian mode, of course. (If his kids leave
the calculator in degree mode they will learn a valuable lesson by example.) I
intentionally wrote the expression as I did rather than in the slightly more
elegant form:

          d = R arcsec ( 1 + h/R )

so that it could be put on a calculator simply. I understand from a colleague
that the arcsecant is a function with doctrinal problems, by the way. I have a
vague recollection form my now distant youth that there was a function called
the "versine" which could also have been used here. Anyone here old enough to
remember that?

>Leigh Palmer also writes:
>   I tried to find a series expansion for arccos ( 1 + z ) in my
>   tables, but there ain't one there. I think I see how to figure one
>   out, but I've got to go home now.
>
>You won't be able to figure one out; there isn't one.  The derivative
>of arccos(1+z) is infinite at z=0.  You will note that the exact form
>doesn't have a Taylor expansion either.

Despite to your claim that there is no way to expand this, I have done so, and
the approximate solution I get, to first order in h/R, is

          d = SQRT(2Rh) x ( 1 - h/2R ),    h << R

The solution you propose as exact is correct for the distance from the observer
to the horizon measured along the line of sight. The usual meaning of horizon
distance is the distance, measured along Earth's surface, between the
observer's geographical coordinates and the horizon.

Leigh
From: newberry@aquarius.as.arizona.edu (Mike Newberry)
Newsgroups: sci.astro
Subject: supernova in M31
Date: 23 Nov 92 22:08:37 GMT
Organization: University of Arizona, Tucson, AZ


New supernova in M31.  The following IAU circular came out Friday:



                                                  Circular No. 5658
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
 
 
NOVA IN M31
     James Bryan, Georgetown, TX, reports his discovery of a nova
in the nuclear bulge of M31, found on Technical Pan photographs
taken by W. Wren using the McDonald Observatory 0.76-m telescope.
The nova is located at R.A. = 0h40m16s.5 +/- 0s.5, Decl. =
+40 58'11" +/- 5" (equinox 1950.0).  A field star (star 51 of
Ciardullo et al. 1987, Ap.J. 318, 520; B = 17.1, V = 16.4) is lo-
cated 11" west-northwest of the nova.  The following V magnitudes
are available (those by Bryan were from Tech Pan photographs with a
0.40-m telescope):  Oct. 26.09 UT, [18.5 (Bryan); Nov. 9.08, 17.2
(Wren); 11.17, 17.2 (Wren); 15.11, 17.2 (Bryan).
     A. V. Filippenko, T. Matheson, and L. C. Ho, University of
California at Berkeley, report that CCD spectrograms (range 320-
1000 nm) obtained on Nov. 18 UT with the Shane 3-m reflector at
Lick Observatory reveal that Bryan's new object is indeed a nova.
Intense hydrogen Balmer emission lines are present on a weak con-
tinuum, as are fainter lines of Fe II.  The spectrum of faint star
located nearby (within 1"-2") is superposed on the nova spectrum;
thus, part of the weak continuum in the spectrum is probably due to
the adjacent star.
 
 
GRS 1915+105 AND B1900+14
     J. Lochner and L. Whitlock, Goddard Space Flight Center, NASA,
and Universities Space Research Association, communicate:  "We have
examined the Vela 5B data in the region of the x-ray transient GRS
1915+105 (IAUC 5590, 5619).  The Vela 5B data base covers the ener-
gy range 3-12 kev from 1969 May to 1979 June.  To a sensitivity of
0.1 Crab, we have found no x-ray activity lasting longer than 2.3
days in the region of GRS 1915+105.  A recently reported soft gam-
ma-ray repeater has been discovered in this region (IAUC 5567, and
C. Kouveliotou, Compton Gamma Ray Conf., St. Louis, 1992 Oct.),
which may be associated with either the transient or the soft gam-
ma-ray repeater B1900+14.  To further check the possible associa-
tion between x-ray transients and soft gamma-ray events, we care-
fully examined the Vela 5B data covering the 1979 March timeframe,
in which Mazets et al. (1979, Sov. Astron. Lett. 5, 343) reported
events from B1900+14.  Good sky coverage allows us to rule out the
presence of any x-ray transient event from either GRS 1915+105 or
B1900+14 in early 1979."
 
 
1992 November 20               (5658)            Daniel W. E. Green
From: steinly@topaz.ucsc.edu (Steinn Sigurdsson)
Newsgroups: sci.astro
Subject: Re: NASA Duplicity?
Date: 18 Nov 92 17:23:32
Organization: Lick Observatory/UCO
NNTP-Posting-Host: topaz.ucsc.edu
In-reply-to: qsi@contrast.wlink.nl's message of 19 Nov 92 00:29:30 GMT

In article <722110960.F00001@contrast.wlink.nl> qsi@contrast.wlink.nl (Peter Kocourek) writes:


   Hi,

    in a recent discussion on a bulletin board here, someone alleged that NASA
    cannot be trusted, because, as he said, it had deliberately deceived the
    public on a number of occasions. Personally, I am rather skeptical of his
    claims (no sources given), so I'd like more knowledgeable folks out here
    to comment on (and preferably, shoot down) these allegations.

    Firstly, it was alleged that NASA increased the size of a mountain on
    Venus (no name given) by a factor of 25, to make it more spectacular,
    and make the evening news.

The Magellan "movie" of the venus radar map was indeed stretched,
 - otherwise it would have looked like a scan across a flat plane,
10 km mountains are just not that impressive on a 6000 km sphere.
This was in fact stated in the releases (that I saw) and is not a
NASA "deception" it's a standard practise in topography.

    Secondly, NASA was alleged to have to have manipulated the results of
    surveys of the hole in the ozone layer, saying it was larger than its
    measurements showed.

 ??? don't know this one, maybe they chanced which contours to plot.

    Thirdly, the well-known COBE graphic, that appeared in all newspapers,
    showing anisotropies in the cosmic background radiation, is alleged to
    have been only a graphic of test results, not of the actual measurements
    themselves.

Well, there exist COBE "synthetic" plots, but the ugly green ones
are real data, massaged a little bit. They're somewhat deceptive
as they're noise dominated, that's why you have to analyse the data,
the published COBE stuff is at the edge of the detectable signal,
quite franky I'd say the raw data is meaningless to the public and
that to say the filtered or synthetic data is "deceptive" is insulting
to whoever bust their ass to get a nice presentable graphic for
public release.

|  Steinn Sigurdsson	|I saw two shooting stars last night		|
|  Lick Observatory	|I wished on them but they were only satellites	|
| steinly@lick.ucsc.edu |Is it wrong to wish on space hardware?		|
| "standard disclaimer"	|I wish, I wish, I wish you'd care - B.B. 1983	|
From: youngs@ccu.umanitoba.ca (Scott D. Young)
Subject: Re: st6 images wanted
Organization: University of Manitoba, Winnipeg, Canada
Date: Fri, 20 Nov 1992 21:21:58 GMT

In <1992Nov19.193343.22313@novell.com> jscherer@db (John Scherer) writes:


> recently downloaded st6 images from sunlight.physics.uiowa.edu, but found that
> the images are 8-bit.  From what I know about the st-6, it is capable of 16-bit images.  I would like to see some 16-bit images if there available..

> John Scherer
> jscherer@sjf.novell.com

   The original images are 16-bit, but when you save them in some formats
   like .TIF, they are reduced to 8-bit. FITS format conversion from the 
   SBIG software DOES NOT WORK PROPERLY, AND WILL NOT GIVE YOU THE 
   ORIGINAL DATA!!  The .GIF may reduce it to 8-bit; I'm not sure.

   Scott Young
   youngs@ccu.umanitoba.ca
Newsgroups: sci.astro
From: andromed@cs.dal.ca (Mike Boschat)
Subject: Swift-Tuttle Observation..Nov.15/16, 1992
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Date: Mon, 16 Nov 1992 22:57:19 GMT

             Swift-Tuttle Observation..Nov.15/16 --2215-2230 UT
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



        MAGNITUDE AND DIAMETER ESTIMATES USING 7x35 BINOCULARS
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 Using the 7x 35 binoculars at the University I determined Swift-Tuttle to
be the following magnitude using the following stars out-of-focus;

BD +20d 03649 at 5.2 Mv
BD +22d 03273 at 5.0 Mv
BD +20d 03675 at 5.1 Mv

 When the field was out-of-focus the comet was brighter than BD +20d 03649 at 5.2 Mv, but very close in brightness to both BD +22d 03273 at 5.0 Mv and
BD +20d 03675 at 5.1 Mv. It was so close that I put the magnitude at 5.1 Mv
based upon this observation.
 Also the comet still appears to be 8 arc minutes in diameter. The faintest star
seen with the naked eye at time of observation was 5.0 Mv.


     LAT= N 44d 39'  LONG= W 63d 36'  Height above sea level= 58 meters

     address; Mike Boschat                           Mike Boschat
           6363 Liverpool St.,                c/o Dr. Owen Hertzman
           Halifax, Nova Scotia,    OR         Dept. Of Oceanography
           CANADA   B3L 1Y1                    Dalhousie University,
                                               Halifax, Nova Scotia
                                                  CANADA   B3J 2H2

          

                  		               Clear skies

						Mike Boschat

                                          andromed@sleet.atm.dal.ca
 ---------------------------------------------------------------------------
|                                   |  "Our problems are man-made,          |
|          JOHN F. KENNEDY          | therefore they can be solved by man " |
|                                   |                                       |
|      ASTRONOMICAL OBSERVATORY     |                 J.F.K.                |
|                                   |                                       |
 ---------------------------------------------------------------------------                                                        	
                     

Newsgroups: sci.astro
From: andromed@cs.dal.ca (Mike Boschat)
Subject: Swift-Tuttle Observation Nov.20/21, 1992
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Date: Fri, 20 Nov 1992 22:27:11 GMT



              Swift-Tuttle Observation; Nov. 20/21--2200-2218 UT
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

               Magnitude Estimate Using 7x35 Binoculars
              -------------------------------------------

 Upon locating the star field with the 7x35s I out-of-focused the field
and the comet was brighter than BD +169191 at 5.2 Mv, it was similar
to BD +22d 03273 at 5.0 Mv, so based on that I give Swift-Tuttle a
magnitude of 5.0.
 Sky was very clear and the limit mag. was 5.0...and COLD !!!

						Clear skies

						Mike Boschat

                                          andromed@sleet.atm.dal.ca
 ---------------------------------------------------------------------------
|                                   |  "Our problems are man-made,          |
|        JOHN F. KENNEDY            | therefore they can be solved by man " |
|                                   |                                       |
|   ASTRONOMICAL  OBSERVATORY       |                 J.F.K.                |
|                                   |                                       |
 ---------------------------------------------------------------------------
From: ronnie@cisco.com (Ronnie B. Kon)
Newsgroups: sci.astro
Subject: Re: Know an adjective for black holes?
Date: 16 Nov 1992 21:55:40 GMT
Organization: cisco Systems, Incorporated
Distribution: world
NNTP-Posting-Host: lager.cisco.com

Holistic?

-------------------------------------------------------------------------------
Ronnie B. Kon          | "You couldn't deny that, even if you used both hands"
ronnie@cisco.com       |
(415) 688-4592         |                   -- The Red Queen                
-------------------------------------------------------------------------------
From: qsi@contrast.wlink.nl (Peter Kocourek)
Newsgroups: sci.astro
Subject: Re: NASA Duplicity?
Date: Sat, 21 Nov 1992 01:39:00

In a message of <18 Nov 92  17:23:32>, Steinn Sigurdsson (2:281/527.0) writes:

 >>  Thirdly, the well-known COBE graphic, that appeared in all newspapers,
 >>  showing anisotropies in the cosmic background radiation, is alleged
 >>  to have been only a graphic of test results, not of the actual
 >>  measurements themselves.
 > 
 > Well, there exist COBE "synthetic" plots, but the ugly green ones
 > are real data, massaged a little bit. They're somewhat deceptive

What exactly are these synthetic plots? And from what you're saying, am I right
in concluding that the "ugly green ones" are not the same as the false color
ones printed in journals such as Nature? If they were different from those,
what are the differences?


YHS:QSI!

Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave
From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Solar Geophysical Data Broadcast for 16 November
Organization: University of Lethbridge
Date: 17 Nov 92 21:49:11 GMT

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 321, 11/16/92
10.7 FLUX=136.7  90-AVG=124        SSN=142      BKI=3232 1222  BAI=008
BGND-XRAY=B7.5     FLU1=4.9E+05  FLU10=9.2E+03  PKI=3122 2222  PAI=007
  BOU-DEV=028,010,021,017,008,013,013,018   DEV-AVG=016 NT     SWF=00:000
 XRAY-MAX= C4.1   @ 1744UT    XRAY-MIN= B5.3   @ 0006UT   XRAY-AVG= C1.2
NEUTN-MAX= +002%  @ 2030UT   NEUTN-MIN= -002%  @ 1845UT  NEUTN-AVG= +0.1%
  PCA-MAX= +0.1DB @ 2355UT     PCA-MIN= -0.5DB @ 1640UT    PCA-AVG= -0.0DB
BOUTF-MAX=55424NT @ 0304UT   BOUTF-MIN=55394NT @ 1920UT  BOUTF-AVG=55415NT
GOES7-MAX=P:+107NT@ 1953UT   GOES7-MIN=N:+002NT@ 0003UT  G7-AVG=+076,+031,+009
GOES6-MAX=P:+124NT@ 2046UT   GOES6-MIN=E:-017NT@ 0250UT  G6-AVG=+093,-008,+031
 FLUXFCST=STD:150,155,155;SESC:145,150,155 BAI/PAI-FCST=007,007,007/010,010,010
    KFCST=2222 3222 2222 3222  27DAY-AP=009,006   27DAY-KP=4311 2212 1221 1223
 WARNINGS=*SWF
   ALERTS=**245STRM:0709-0803UTC
!!END-DATA!!
Newsgroups: sci.astro
From: chapman@ims.com (Dave Chapman)
Subject: Re: Galilean Electrodynamics?
Organization: Integrated Measurement Systems, Inc.
Date: Wed, 18 Nov 1992 16:34:21 GMT

In article <schlegel.722034259@cwis>, schlegel@cwis.unomaha.edu (Mark Schlegel) writes:
|> The past few months in Sky and Telescope magazine I have been seeing this
|> ad for a bimonthly publication called "Galilean Electrodynamics" written
|> by a group of professors. What is the story on this group?  The editorial
|> board is made of up of scientists and engineers (five are listed in the ad)
|> Edit. Board:       
|>         Thomas Barnes, U of Texas, Prof. Emeritus
|>         Howard Hayden, Univ. of Connecticut, Prof. of Physics
|>         P. Parshin, Academy of Civil Aviation, St. Peterburg, Russia
|>         Cynthia Whitney, Tufts Univ.
|> Editor:
|>         Petr Beckmann, Prof. Emeritus of Electrical Eng., Univ. of Colorado/
|>                                                                 Boulder
|>                                                                 
|> Does anyone know about whether the papers published by this group have any
|> validity in the general physics world?  They seem to believe there are 
|> obvious contradictions between general rel. and observation.
|> 
|> Mark Schlegel, Schlegel@unomaha.edu
|> 

They don't like special relativity either.

Thomas Barnes is a creationist and the author of a book that tries to
prove that the earth is only 6 thousand years old by reverse
extrapolation of the earth's magnetic field.

-- 
Dave Chapman   	       	       	    | chapman@ims.com
Integrated Measurement Systems	    |
9525 SW Gemini Dr.		    | work 503 626 5373
Beaverton, Oregon 97005 	    |
Newsgroups: sci.astro
From: jsmill01@ulkyvx.louisville.edu
Subject: Jan H. Oort - obituary (long)
Date: Tue, 17 Nov 1992 23:25:03 GMT
Organization: University of Louisville

A couple of weeks ago, someone asked for information/obituary on Jan 
Oort.  I do not recall a followup, so I am posting the following.  It 
appeared in the Thursday edition of the Courier Journal (our local 
paper) on 11/12.  Sorry for the delay, but business precluded me from 
posting sooner.

Scott Miller, Program Coordinator
Rauch Memorial Planetarium
University of Louisville
jsmill01@ulkyvx.louisville.edu
==============================================================================
JAN H. OORT DIES AT 92; CHARTED SOLAR SYSTEM'S PLACE IN THE MILKY WAY

By John Noble Wilford - New York Times News Service

Jan H. Oort, the Dutch astronomer who made major discoveries about the 
dynamics of the Milky Way galaxy, the mass of the cosmos, and the 
origin of comets, died last Thursday in Leiden, the Netherlands.  He 
was 92 and lived in Leiden.

He died of complications from a broken hip, Dr. Tyeerd Van Albada, an 
astronomer at the University of Groningen in the Netherlands, said 
yesterday.  "He was the father of Dutch astronomy," Van Albada said of 
Oort.

As an astronomy professor at the University of Leiden and for years 
director of its observatory, Oort established a reputation as one of 
the century's foremost explorers of the universe.  One of his earliest 
and most important achievements was to establish the rotation of the 
Milky Way and to chart the solar system's place in that galaxy.

Soon after he joined the Leiden faculty in 1926, Oort obtained the 
first direct evidence of the Milky Way's rotation.  Through complex 
calculations, he measured the relative velocities of star moving with 
the rotating galaxy and deduced their distances from the galactic 
center.  In this way, he determined that the sun and its planets were 
not even close to the galaxy's center but 30,000 light-years away, in 
the galactic hinterland.

"Like a modern Copernicus, Oort showed that our position in nature's 
grand scheme was not so special," said Dr. Seth Shostak, an astronomer 
at the SETI institute in Mountain View, Calif., who worked for many 
years at the University of Groningen.

Oort was elected to lead several international astronomical groups, 
was awarded the Vetlesen Prize by Columbia University and received 
many honorary degrees, including ones from Oxford, Cambridge, and 
Harvard universities.

Oort is survived by his wife, two sons and several grandchildren and 
great-grandchildren.
Newsgroups: sci.astro
From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
Subject: Re: I can't see stars anymore at night with naked eye
Organization: AT&T
Date: Sat, 21 Nov 1992 21:24:51 GMT

But seriously, folks, the haze/light pollution in my area has made all the
stars not visible.  Has anyone who lives in/near large cities verify my
observation?  Another possibly related observation is that a clear daytime
sky is not as a deep blue at zenith as it used to be.  Did that volcano
put -that- much dust into the upper atmosphere?

Have observatories and amateurs with telescopes in dark areas noticed a
drop in star brightness?  Or is the dust (assuming that that's what it is)
reflecting back down more city light?  

I live about 20 miles from New York City, a big light pollution source.
Newsgroups: sci.astro
From: dsc@gemini.tmc.edu (Doug S. Caprette Bldg. 28 W191 x3892)
Subject: Observed comet positions requested.
Organization: NASA GSFC CDP VLBI
Date: Mon, 16 Nov 1992 15:41:08 GMT


We looked for comet Helin-Larenc (1991l) last night, November 16, from about 
1 to 5 hours UT apparently without success.  Can any observers give us an indi-
cation of how close it is to the position in the ephemeris posted to Sci.astro,
or, how large the coma is?

As they say on the net, thanks in advance.
--
dsc@gemini.gsfc.nasa.gov  
 |  Regards,         |   Hughes STX                |    Code 926.9 GSFC        |
 |  Doug Caprette    |   Lanham, Maryland          |    Greenbelt, MD  20771   |
 -------------------------------------------------------------------------------
"Questions are a burden to others, answers a prison for oneself."
                                  -- Village proverb
Newsgroups: sci.astro,sci.geo.geology,sci.physics,alt.sci.planetary
From: cain@geomag.gly.fsu.edu (Joe Cain)
Subject: internal heat, Jupiter and Saturn
Followup-To: sci.astro
Summary: questions on mechanisms for internal heat sources
Organization: Florida State University Geology Dept.
Date: Sat, 21 Nov 92 18:41:52 GMT

On p. 260 of "Introduction to the Solar System," Wagner writes "Even
though Jupiter failed to become a star, some thermal energy is
produced in its core by gravitational pressure." 

My understanding of planetary processes is that the gravitational
potential energy is traded off as heat as denser material settles
towards the center. I would assume that this is the process to which
he refers, but am puzzled by the phrase "gravitational pressure." Does
anyone have any ideas on this, like IS there some other mechanism I do
not know, or did he just write in an imprecise way?

	One other possibility that comes to mind might be if energy is
given off as molecular hydrogen goes to the higher pressure metallic
form. Is this the theorized mechanism for generation instead of, or in
addition to, the settling to lower gravitational potential energy? 

	Hubbard, writing in New Solar System (pp. 133-134) describes
an additional complication in Saturn based on its lower ratio of
Helium observed in its atmosphere. He discusses the "helium rain" that
may be occuring in the metallic hydrogen phase of Saturn which is
possible because it is cooler than that of Jupiter. Ingersoll writes
on p. 142 of NSS that Saturn's heat output exceeds that of Jupiter per unit
mass (total emitted is 1.8 times that received from the Sun vs 1.7 for
Jupiter). 
Is the helium rain supposed to be the reason for this?


Joseph Cain		cain@geomag.gly.fsu.edu
cain@fsu.bitnet		scri::cain
From: jscherer@db (John Scherer)
Newsgroups: sci.astro
Subject: st6 images wanted
Date: 19 Nov 92 19:33:43 GMT
Organization: Novell, Inc.
X-Newsreader: Tin 1.1 PL4


 recently downloaded st6 images from sunlight.physics.uiowa.edu, but found that
 the images are 8-bit.  From what I know about the st-6, it is capable of 16-bit images.  I would like to see some 16-bit images if there available..

 John Scherer
 jscherer@sjf.novell.com
Newsgroups: sci.astro