Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_5/V16NO501.TXT

Internet Message Format | 1993-07-13 | 8KB

Date: Fri, 30 Apr 93 05:10:49
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #501
To: Space Digest Readers
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Space Digest                Fri, 30 Apr 93       Volume 16 : Issue 501

Today's Topics:
                 Gamma Ray Bursters. WHere are they.
             Two-Line Orbital Element Set:  Space Shuttle
                         Vandalizing the sky.

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----------------------------------------------------------------------

Date: 28 Apr 93 21:51:46 GMT
From: Ethan Bradford <[e-mail]>
Subject: Gamma Ray Bursters. WHere are they.
Newsgroups: sci.astro,sci.space

In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:

   _The_ problem with Oort cloud sources is that absolutely
   no plausible mechanism has been proposed. It would have
   to involve new physics as far as I can tell. Closest to
   "conventional" Oort sources is a model of B-field pinching
   by comets, it's got too many holes in it to count, but at
   least it was a good try...

So you have a plausible model for GRB's at astronomical distances?
Recent observations have just about ruled out the merging neutron star
hypothesis, which had a lot of problems, anyhow.  We have to look for
implausible models and what is fundamentally allowed independent of
models.

A paper on the possibility of GRB's in the Oort cloud just came
through the astrophysics abstract service.  To get a copy of this
paper, send a message to [e-mail] with the subject
line
  get 9304001


Here is the abstract of that paper.

   The currently favored explanation for the origin of \GRBs puts them
   at cosmological distances;
   but as long as there is no distance
   indicator to these events all possible sources which are
   isotropically distributed should remain under consideration. This is
   why the Oort cloud of comets is kept on the list,
   although there is no known mechanism for generating \GRBs
   from cometary nuclei. Unlikely as it may seem, the possibility that \GRBs
   originate in the solar cometary cloud
   cannot be excluded until it is disproved.

   We use the available data on the distribution of \GRBs (the BATSE
   catalogue up to March, 1992), and
   the Catalogue of Cometary Orbits  by Marsden and Williams (1992) to
   investigate whether there is any observational indication for correlations
   between the angular distributions of \GRBs and comets' aphelia,
   assuming that the distribution of aphelia direction reflect,
   at least to some extent, true variations
   in the column density of the Oort cloud. We also apply the $\vov$
   test to both distributions.

   We have  performed a variety of statistical tests (a Kolmogorov-Smirnov
   test for the distributions in galactic latitude, a
   $\chi^2$ test for the spherical multiple moments, and a 2-D
   cross-correlation analysis), including testing sub-samples for
   isolating the effect of possible observational biases.
   These tests imply that it is unlikely that the two distributions agree, but
   the statistical significance  is not sufficient for ruling out any
   connection with complete confidence. We performed Monte-Carlo simulations
   which show that only when the number of bursts exceeds $\sim 800$
   it is possible to rule out a correlation between the angular distributions.
   Currently,
    it is only the combination of these tests  with the large disagreement
   found for the $\vov$ parameter which makes the Oort
   cloud of comets unlikely to be related to \GRBs.

------------------------------

Date: Wed, 28 Apr 1993 21:06:41 GMT
From: TS Kelso <[e-mail]>
Subject: Two-Line Orbital Element Set:  Space Shuttle
Newsgroups: sci.space

The most current orbital elements from the NORAD two-line element sets are
carried on the Celestial BBS, [phone], and are updated daily (when
possible).  Documentation and tracking software are also available on this
system.  As a service to the satellite user community, the most current
elements for the current shuttle mission are provided below.  The Celestial
BBS may be accessed 24 hours/day at 300, 1200, 2400, 4800, or 9600 bps using
8 data bits, 1 stop bit, no parity.

Element sets (also updated daily), shuttle elements, and some documentation
and software are also available via anonymous ftp from archive.afit.af.mil
(129.92.1.66) in the directory pub/space.

STS 55
1 22640U 93 27  A 93117.91666666  .00044808  00000-0  13489-3 0    63
2 22640  28.4614 259.3429 0005169 259.6342  61.8074 15.90673799   201
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]                    Air Force Institute of Technology

------------------------------

Date: 28 Apr 93 08:02:51 GMT
From: Jeff Cook <[e-mail]>
Subject: Vandalizing the sky.
Newsgroups: sci.astro,sci.space

In article <[e-mail]> [e-mail] (SCOTT I CHASE) writes:

>In article <[e-mail]>, [e-mail] (Phil G. Fraering) writes...
>>[e-mail] (Jeff Cook) writes:
>>....
>>>people in primitive tribes out in the middle of nowhere as they look up
>>>and see a can of Budweiser flying across the sky... :-D
>>
>>Seen that movie already...
>
>Actually, the idea, like most good ideas, comes from Jules Verne, not
>_The Gods Must Be Crazy._...

My comment was off the top of my head; I wasn't aware that it had
already been thought of.  Guess it's true that there's nothing new under
the sun (or in this case, the flying billboards.)


--

Jeff Cook                                  [e-mail]

------------------------------

Newsgroups: sci.astro,sci.space

From: Dave Stephenson <[e-mail]>
Subject: Re: Vandalizing the sky.
Message-Id: <stephens.736028275@ngis>
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[e-mail] (Keith Mancus) writes:
>>>[e-mail] (Jeff Cook) writes:
>>>>people in primitive tribes out in the middle of nowhere as they look up

That has sort of happened for real. Back in the 1920's travellers
in the Sudan would find strange cigar shaped designs on native huts.
When asked the locals would say it was a picture of the great omen
that appeared in the sky. This was LZ 53 a zepplin flying from Bulgaria
to German East Africa with supplies in 1917 (and back since it was fooled
by the British secret service.)
--
Dave Stephenson
Geological Survey of Canada
Ottawa, Ontario, Canada
Internet: [e-mail]

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End of Space Digest Volume 16 : Issue 501
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