HDTenEightyP/NetNews huggingface dataset:
From: hbh@athena.mit.edu (Heidi Hammel)
Subject: Re: Lunar Phenomena question
Organization: Massachusetts Institute of Technology
Date: Wed, 6 Jan 1993 21:17:15 GMT

andromed@Hail.ATM.Dal.Ca (Mike Boschat) writes:
>Have any observers or observatories seen any  TLP's (Transient
>Lunar Phenomena) lately ? [...] Is the search still going on
> for them by amateurs and some professionals.?

I just read an article in a recent Icarus describing observations
of these phenomena and discussing some of the current hypotheses
for their causes.  I don't remember which month, but it was very
recent, certainly within the last 7 issues.

heidi
--
    Heidi B. Hammel   (hbh@astron.mit.edu)   MIT 54-416   EAPS Dept.
Newsgroups: sci.astro
From: chaloux@mandolin.mitre.org (Dave Chaloux)
Subject: SCTs and their moveable mirrors.
Reply-To: chaloux@mandolin.mitre.org (Dave Chaloux)
Organization: The MITRE Corporation, McLean, Va
Date: Mon, 11 Jan 1993 21:54:09 GMT

It is a well established result that SCTs which have moveable mirrors for
focusing are at their best at only one point among their many possible
positions. Since many things require the mirrors to move in order to
focus, it is unlikely that Joe Amateur is using the mirror to its best
capabilities. Different eyepieces, different diagonals, differences in
distance to the object focused upon, etc. will all change the position
of the mirror required to focus.

It occurred to me that it might??? be possible to use this fact to advantage.
Jim's Mobile now sells a focuser for SCTs that works without moving the
mirror (What an idea!). If positions of the mirror on one side of perfect
lead to undercorrected images and positions on the other lead to over
corrected images you could use this to tune you telescope for no
sperical abberation.

1) Do star test using JMI focuser (or other brand that doesn't shift mirror.)
2) Note whether under or over corrected. The star test is very sensitive at
revealing this if you know what to look for.
3) Using the focuser that moves the mirror (the standard unit) compensate for
under or over correction.
4) Star test again. Iterate above steps till everything is "just right".

Any chance this will actually work in practice? 

BTW, yes I am aware that what you gain by moving the mirror is tremendous
depth of focus and lots of ability to move the distance of the eyepiece,
camera, etc. with regards to the mirror.
From: ao@elixir.e.kth.se (Anders Ohlsson)
Newsgroups: sci.astro
Subject: Astronomical events
Keywords: Apogee, Perigee, Eclipses
Date: 11 Jan 93 14:28:40 GMT
Reply-To: ao@elixir.e.kth.se (Anders Ohlsson)
Organization: Royal Institute of Technology, Stockholm, Sweden


	Hi all!

	Does anybody have some accurate (+/- 1 minute) data for the following:

		* Solar eclipses
		* Lunar eclipses
		* Apogees and perigees of the moon

	I have implemented some of the formulae in Jean Meeus book,
	"Astronomical Algorithms". His formulae for perigee gives a maximum
	error of 31 minutes (mean error 3 minutes) for the perigees of
	1987-2022 and I would like to see how much better I can make it.
	Pointers to tables of accurate data would be much appreciated.

	Also, if you have any information on algorithms to calculate more
	data on lunar and solar eclipses. The data I would like to be able
	to calculate is for example as given in this excerpt from a Swedish
	almanac:

	"Partial solar eclipse of Nov 13, 1993: Starts at 19.46 GMT,
	 138 degrees 2 minutes East, 31 degrees 17 minutes South and ends
	 at 23.43 GMT, 67 degrees 45 minutes West, 48 degrees 44 minutes
	 South. Maximum accurs at 21.45 GMT when it is 93% of the Sun's
	 diameter."

	Please reply by e-mail.



				Many thanks in advance,

						Anders Ohlsson
						ao@elixir.e.kth.se
Newsgroups: sci.astro
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Subject: Re: Purchasing a Newtonian Reflector
Organization: AI Programs, University of Georgia, Athens
Date: Wed, 6 Jan 1993 05:56:10 GMT

Buy the one with the steadiest mount!

-- 
:-  Michael A. Covington     internet mcovingt@uga.cc.uga.edu :    *****
:-  Artificial Intelligence Programs       phone 706 542-0358 :  *********
:-  The University of Georgia                fax 706 542-0349 :   *  *  *
:-  Athens, Georgia 30602-7415 U.S.A.     amateur radio N4TMI :  ** *** **
From: higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey)
Newsgroups: sci.astro
Subject: Cockeyed Binocs(was Re: Cheap or Expensive Binoculars?)
Date: 11 Jan 93 17:21:51 -0600
Organization: Fermi National Accelerator Laboratory
NNTP-Posting-Host: fnalf.fnal.gov

In article <mc0ZVB1w165w@bluemoon.use.com>, gerry@bluemoon.use.com (Gerard M. Foley) writes:
> 
>     In 1986, in preparation for a cruise off the Brazilian coast, 
> nominally to see comet Halley, I bought 7 X 50 K-Mart Focal brand 
> binoculars for about $50.  These rubber encased binoculars gave very 
> satisfactory performance until recently.  Now they are decollimated, so 
> that star images are double.  My visual accomodation can fuse bright 
> images, in the daytime.

I had a similar experience with my cheap 10x50s.  Now I just leave one
lens cap on and observe with a "monocular," but this is hardly
satisfactory.

Is there any hope that I could recollimate this cockeyed instrument
somehow?

     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     HIGGINS@FNAL.BITNET
   -   -       Internet:  HIGGINS@FNAL.FNAL.GOV
     ~         SPAN/Hepnet:      43011::HIGGINS 
Xref: sparky sci.astro:13677 sci.space:18798 news.answers:4957
From: gawne@stsci.edu
Subject: Re: 49 ERIDANI
Organization: Space Telescope Science Institute
Distribution: na
Date: Tue, 12 Jan 1993 16:25:09 GMT

In article <1993Jan12.133703.21959@cerberus.ulaval.ca>, 
beaucham@astro.phy.ulaval.ca (Dominique Beauchamp) writes:
> It seems that HST has reported the "constant" star 49 Eri to
> be a possible variable.
> 
> I did two measurement on Jan 12 1993 from Quebec City (~46.8N~71.2W).
> I used bino 8x56 and the comparision stars given in Sky&Telescope
> for February.  
> 
> 0105 UT	mv 5.3 +/- 0.1
> 0222 UT       mv 5.3 +/- 0.1
> 
> 
> I hope it can be useful!
> 
> Dominique Beauchamp

Thank you.  It is likely to be more useful if you get it into print in
something like the Astronomical Journal, or one of the AAVSO publications.

-Bill Gawne,  Space Telescope Science Institute
Newsgroups: sci.astro
From: ledlow@triton.unm.edu (Michael Ledlow PHYS)
Subject: Re: Advice wanted:  CDROM star charts
Date: Sat, 09 Jan 93 18:38:41 GMT
Organization: University of New Mexico, Albuquerque

In article <1993Jan9.001847.24388@hparc0.aus.hp.com> linas@hparc0.aus.hp.com (Linas Petras) writes:
>One of the best sources for catalogs on CDROM, (if not the best) is NASA 
>Selected Astronomical Catalogs Volume 1, from the Astronomical Data Center.
>It contains from memory 150 different catalogs, including the SAO catalog
>which gives you about 250,000 star positions.
>
>I'm not sure of the address I ordered my from (cost ~US$30.00), but perhaps
>someone else can give you an order address.
>

In the book from the CD, it has a contact address for the ADC group at 
NASA.  

  Dr. Jaylee M. Mead
  Coordinated Request and User Support Office
  National Space Science Data Center
  Mail Code 933.4
  Goddard Space Flight Center
  Greenbelt, MD  20771

Phone (301) 286-6695
FAX   (301) 286-4952
e-mail : request@nssdc.gsfc.nasa.gov

--Michael


Newsgroups: sci.astro
From: dj@ekcolor.ssd.kodak.com (Dave Jones)
Subject: Re: Quantisation of REDSHIFT
Organization: Morituri Te Salutent, Inc.
X-Newsreader: TIN [version 1.1 PL7]
Date: Fri, 8 Jan 93 19:23:28 GMT

Stupendous Man (richmond@spiff.Princeton.EDU) wrote:
>  baresson@cbnewsi.cb.att.com (pete.oram) writes:
>  
> po> 4. What other explanations are there for the redshift quantisation if it
> po> doesn't just correspond to the velocity of the source?
> 
>   Tom Van Flandern replies: 
> 
> TVF> If redshifts are quantized for us and are caused by velocity alone, 
> TVF> they cannot be quantized for most other observers.  
> TVF> So either we are in a special place in the universe, 
> TVF> or cosmological redshift is not due mainly to expansion velocity.  
> 
>   I just hate getting pulled into these cosmological discussions, but
> I can't resist.  If it is true that galaxy redshifts are "quantized",
> and I don't believe it yet, here's a simple explanation for the fact
> that retains the "redshift due to velocity alone" idea:  galaxies 
> occur in clumps, with gaps in between the clumps containing few galaxies.
> If the clumps occur at regular intervals, then any observer, anywhere,
> will see "quantized redshifts" due to the expansion of the universe.
> N'est-ce pas?
>
If the clumps are regularly spaced everywhere that's just as amazing as
quantizing redshifts in the first place....

There have been reports of absorption lines in quasar spectra showing 
a few distinct redshift values rather than a continuum, indicating that 
matter between here and the quasar follows the void-matter-void pattern.
However, a sample of redshifts over enough of the sky will average out this
effect unless the spacing of matter and voids is the same in all directions.
As I noted before, this would be as amazing as redshift quantization.
 

--
||------------------------------------------------------------------------
||Dave Jones (dj@ekcolor.ssd.kodak.com)|Eastman Kodak Co. Rochester, NY  |
Newsgroups: sci.astro,alt.sci.planetary
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: History of Earth/Moon system
Date: Wed, 6 Jan 1993 18:26:49 GMT
Organization: U of Toronto Zoology

In article <1993Jan6.155311.21200@mailer.cc.fsu.edu> cain@geomag.gly.fsu.edu (Joe Cain) writes:
>... Also, is there any
>significance to the 10ish hour rate being close to that of Jupiter and
>Saturn? (i.e. is there some theory that would guide the initial
>rotation rate of material accreted in the original nebula, perhaps as
>a function of distance from the Sun?).

Actually, last I heard, current speculation is that something on the
order of 8-10 hours is the rotation period you naturally get from the
accretion process.  Everything in the solar system that's much slower
than that has either obvious tidal effects at work or a probable
history of violent upsets.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
From: bluelobster+@CMU.EDU (David O Hunt)
Newsgroups: sci.astro
Subject: Re: Galileo coverup
Date: 4 Jan 93 06:53:10 GMT
Article-I.D.: andrew.IfG6hqu00XsFRFwEc9
Organization: Carnegie Mellon, Pittsburgh, PA

Is there anyway of telling that the hammering is making progress (aside
from rib release)?

David Hunt
bluelobster+@cmu.edu
Newsgroups: sci.astro
From: buehler@space.mit.edu (Royce Buehler)
Subject: Re: "Space Potato" in Journal of Irreproducible Results
Organization: MIT Center for Space Research
Date: Mon, 4 Jan 1993 20:14:25 GMT

 kayser@nssdca.gsfc.nasa.gov writes:

> >There's a note in the December Journal of Irreproducible Results that

> It's been a while since I've seen the JIR. How can one get a copy, these days?

Having no connection with this excellent source of the Straight Poop, I can
declare without fear of ethics violations that subscriptions can be had from:

	Journal of Irreproducible Results
	Blackwell Scientific Publications, Inc.
	238 Main Street
	Cambridge, MA 02142 USA
	(800) 759-6102

It seems to be undergoing a resurgence or regurgitation in recent years, due
perhaps to the publicity engendered by its annual First Annual Ig Nobel Prize
award ceremony .

-- 
Royce Buehler	buehler@space.mit.edu	(617)-253-9766
	Many things do not happen as they ought.
	Most things do not happen at all.
	It is for the conscientious historian to correct these defects.
   ----Herodotus (?)
Newsgroups: sci.astro
From: chris@chrism.demon.co.uk (Chris Marriott)
Subject: Re: Galileo's antenna 
Distribution: world
Organization: None
Reply-To: chris@chrism.demon.co.uk
X-Mailer: Simple NEWS 1.90 (ka9q DIS 1.19)
Date: Mon, 4 Jan 1993 19:24:12 +0000

In article <4JAN199317595383@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov writes:

>In article <IfG6hqu00XsFRFwEc9@andrew.cmu.edu>, bluelobster+@CMU.EDU (David O
> Hunt) writes...
>>Is there anyway of telling that the hammering is making progress (aside
>>from rib release)?
>
>The sun sensor and wobble measurements are the two main indicators.  The
>shadow of the antenna falling across the sun sensor is used measure the extent
>the antenna is open.  Since the stuck ribs cause the antenna to be
>more open on one side than the other (asymmetrically deployed) and the
>spacecraft is spinning, a slight wobble exists which can be measured.
>Also, when the antenna is fully open, a couple of switches will be activated.
>After the first antenna hammering last week, the sun sensor and wobble
>measurments indicated a change in the antenna, the first change measured
>since the initial antenna deployment attempt in April 1991.  The recent 
>sun sensor data indicates that the antenna is "more open", and this is either 
>due to one of the three stuck ribs popping loose, 
>or increased tension on the antenna is causing it to bend out more.  Several 
>more hammering sessions are scheduled this month to keep applying more force 
>on the ballscrew to free the stuck ribs.
>     ___    _____     ___
>    /_ /|  /____/ \  /_ /|     Ron Baalke         | baalke@kelvin.jpl.nasa.gov
>    | | | |  __ \ /| | | |     Jet Propulsion Lab |
> ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Choose a job you love, and
>/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | you'll never have to work
>|_____|/  |_|/       |_____|/                     | a day in your life. 
>
>

Is the HGA of no use at all unless completely open?  Couldn't a partially
open antenna be used at all - or does the fact that it's not a parabola
(or whatever) make it totally useless?

Chris
-- 
--------------------------------------------------------------------------
| Chris Marriott                           | chris@chrism.demon.co.uk    |
| Warrington, UK                           | BIX: cmarriott              |
| (Still awaiting inspiration              | CIX: cmarriott              |
|  for a witty .sig .... )                 | CompuServe: 100113,1140     |
--------------------------------------------------------------------------
 
Newsgroups: sci.astro
From: pahakala@cc.helsinki.fi
Subject: HST proposals
Organization: University of Helsinki
Date: Tue, 5 Jan 1993 13:11:27 GMT

Does anyone know how I could get the list of approved HST proposals?

                             Pasi Hakala
                             Observatory & Astrophysics Lab.
                             Univ. of Helsinki
                             Finland
Newsgroups: sci.astro
From: mt90dac@brunel.ac.uk (Del Cotter)
Newsgroups: sci.astro
Subject: Re: History of Earth/Moon system
Date: 7 Jan 93 13:23:59 GMT
Organization: Brunel University, West London, UK

In article <1993Jan6.124737.14935@mailer.cc.fsu.edu> Joe Cain writes:
>
>	Does anyone have a reference for the present best estimates on
>the distance of the Moon from the Earth in geologic time 
>[text deleted]
>	I have also read that the Earth day was like 11 hours 2 Ga
>ago, and 22 h at about 400 Ga.
>[text deleted]
>	I assume that the tidal recession rate must be strongly
>dependent on a number of factors, including distance. Is there a
>theory that illustrates such changes?
>
This may be off-subject for you, but we have a couple of books on the
earth's rotation in our library:

AUTHOR:  Interdisciplinary Winter Conference on Biological Clocks and Changes
         in the Earth's Rotation , Geophysical and Astronomical Consequences,
         1974, University of Newcastle upon Tyne
TITLE:   Growth rhythms and the history of the earth's rotation, edited by G.D.
         Rosenberg and S.K. Runcorn
            London (etc.), Wiley-Interscience, 1975
            xvi,559p, ill, maps
NOTES:   '... (papers) presented at the Interdisciplinary Winter Conference on
         Biological Clocks and Changes in the Earth's Rotation , Geophysical
         and Astronomical Consequences. The conference was held at the School
         of Physics, University of Newcastle upon Tyne, 8-10 January 1974' -
         Preface

                       CLASSMARK:  QB633.I57                              

AUTHOR:  Lambeck, Kurt
TITLE:   The earth's variable rotation, geophysical causes and consequences,
         (by) Kurt Lambeck
            Cambridge (etc.), Cambridge University Press, 1980
            Cambridge monographs on mechanics and applied mathematics
            xi,449p, ill

                       CLASSMARK:  QB633.L35                             

The first deals mostly with palaeological evidence, while the second deals,
if I remember right, with theory.
-- 
 ',' ' ',','  |                                                  |  ',' ' ',','
   ', ,','    |       Del Cotter       mt90dac@brunel.ac.uk      |    ', ,','  
     ','      |                                                  |      ','    
Newsgroups: sci.astro
From: an4773@anon.penet.fi
Subject: - . ... -
Organization: Anonymous contact service
X-Anonymously-To: sci.astro
Date: Tue, 5 Jan 1993 22:59:31 GMT

- . ... -
-------------------------------------------------------------------------
To find out more about the anon service, send mail to help@anon.penet.fi.
Due to the double-blind system, any replies to this message will be anonymized,
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From: apryan@vax1.tcd.ie
Newsgroups: sci.astro
Subject: Re: Bright planet in the evening sky
Date: 13 Jan 93 00:51:49 GMT
Organization: Trinity College Dublin

The planet is Venus.

 On 1993 Jan. 13 00:32:10UT Venus was 110,183,035km (68,464,564 miles)
 from Earth. It can come within 40 million km (25 million miles) of
 Earth. Venus' orbit is the most circular of all the planets (e=0.00678).
 Its perihelion distance is about 107,470,000km (66,780,000 miles) and its
 aphelion distance is about 108,946,000 km (67,696,000 miles).

 As you are in the U.K. what you need to do is call the new telephone
 ASTRONOMY AND SPACE HOTLINE on 0891-88-1950 which will tell you what to
 see in the sky over the British Isles every week (full update every
 Sunday night but listen out for news of the discovery of new comets or
 novae mid-week). Calls cost 48p/min peak, 36p/min all other times. You
 should then be able to locate Mars and Jupiter as well as the Russian
 space station Mir with two men on board. All are visible to the naked eye.
Newsgroups: sci.astro
From: davem@ee.ubc.ca (Dave Michelson)
Subject: Re: Galileo's antenna
Organization: University of BC, Electrical Engineering
Date: Tue, 5 Jan 1993 01:17:05 GMT

In article <726175452snz@chrism.demon.co.uk> chris@chrism.demon.co.uk writes:

>Is the HGA of no use at all unless completely open?  Couldn't a partially
>open antenna be used at all - or does the fact that it's not a parabola
>(or whatever) make it totally useless?
>

The gain of a parabolic reflector decreases rather rapidly as its shape 
deviates from an ideal paraboloid :-( 
 
Of course, if only a portion of the paraboloid is damaged, say the outer
rim or an angular sector, and the rest is in prsitine condition, then
the net gain is simply proportional to the portion which is intact.
 
If the surface is quite irregular, the Ruze relation provides a method
for estimating the reduction in gain due to random deviations from
perfection:
 
                k = cos^2 4*pi*delta/lambda
 
where k is the gain-loss factor (0 < k < 1), delta is the rms deviation from
perfection, and lambda is the operating wavelength.  

The Ruze relation is used to estimate the manufacturing tolerances for a
particular reflector.  A reflector suitable for use at 6 GHz may be rather  
disappointing when used at 12 GHZ, for example.
 
As a footnote, the proposal to upgrade Canada's Algonquin Radiotelescope
for use at millimetre wavelengths for studies of molecular clouds involved
reducing the rms deviation of the inner tw0-thirds of the dish and
replacing the feed.  The outer third of the dish would be so "rough" at
100 GHz that it would simply not contribute.
 
This doesn't directly answer your question but I hope it gives you a bit
more insight...
 
--
Dave Michelson
davem@ee.ubc.ca
Newsgroups: sci.astro,sci.space,sci.physics,sci.environment
From: stgprao@st.unocal.COM (Richard Ottolini)
Subject: Re: averting doom
Organization: Unocal Corporation
Date: Wed, 30 Dec 1992 16:14:45 GMT

In article <JMC.92Dec29211051@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:
>from a U.P. story
>
>	     WASHINGTON (UPI) -- Life on Earth as we know it will
>     come to an end in 1,500 million years and the planet will
>     look more like its dusty, volcanic sister Venus in 2,500
>     million years, scientists said Wednesday.

If we can't model the weather more than 5 days in advance nor agree on
climate prediction in 50 years, who would have any confidence in this
speculation?
Newsgroups: sci.astro
From: chaloux@mandolin.mitre.org (Dave Chaloux)
Subject: Re: 127ED Meade Refrators: Info Please
Reply-To: chaloux@mandolin.mitre.org (Dave Chaloux)
Organization: The MITRE Corporation, McLean, Va
Distribution: na
Date: Mon, 11 Jan 1993 21:19:25 GMT

>Dierick Dominique writes:

>Me too ...
>I am looking to buy a 7 inch ED, but I'd really like first to see some
>results with it ( photographs of deep-sky and planets ) to compare the
>refractor with the higher priced EDT from AstroPhysics. 
>Any comments and experiences welcome. I know the 3 lens design probably
>is better, but is it worth the nearly double price you have to pay for it ?

I haven't looked through the new Meade Refractors so I can't address that
specifically. However, I would caution anybody about using photographs as
a way of judging between telescopes for the following reasons:

1) Photographic use of the telescope is somewhat less demanding (unless we
are talking eyepiece projection as in planets) than high power visual use of
the optics. You did mention Planetary photography so you may be aware of this.

2) The way the photographs are processed to bring out detail, etc. is likely
to have a big effect. (Did they sandwich negatives, etc.)

3) Conditions under which the photographs were taken are likely to be different.
Also includes variables like the format of the film used.

I for one would love it if the Meade Refractors are great and the mounts
are equally good but I for one remain very sceptical. I want to eventually get
a 7" Apo Refractor and the thought of paying less has its appeal.
Newsgroups: sci.astro
From: rchilder@magnus.acs.ohio-state.edu (Russell K Childers)
Subject: Re: Galileo coverup
Organization: The Ohio State University
Distribution: usa
Date: Tue, 5 Jan 1993 04:16:57 GMT

In article 26502 of sci.astro,
    baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:

>Seventy percent of the science objectives can be obtained using the Low Gain
>Antenna.  Compressions techniques (10x improvment) with upgrades to the 
>Deep Space Network (another 10x improvement) will give an effective 100x
>improvement of the LGA's 10 bps transmission rate that it will be using

If the HGA indeed does successfully deploy, could these techniques be
used to perform even more experiments?  Since the modifications for data
compression are being considered, perhaps they could be modified to be
used with the HGA.

Russ Childers
rchilder@magnus.acs.ohio-state.edu

Newsgroups: sci.astro,rec.radio.shortwave