HDTenEightyP/NetNews huggingface dataset:
From: Jeff.Cook@FtCollinsCO.NCR.COM (Jeff Cook)
Newsgroups: sci.astro
Subject: Re: sci.astro.amateur?
Date: 7 Apr 92 09:35:09 GMT
Article-I.D.: pigpen.JEFF.COOK.92Apr7103509
Organization: none
In-reply-to: jcastner@isis.cs.du.edu's message of 7 Apr 92 00:15:40 GMT

In article <1992Apr7.001540.20151@mnemosyne.cs.du.edu> jcastner@isis.cs.du.edu (John Castner) writes:

>   I was wondering if anyone else out there saw a need for a new
>newsgroup, devoted to amateur astronomy, and containing primarily
>the many discussions on telescopes and telescope making presently
>found in this group.  I feel that as someone interested in astronomy,
>but not interested observing (other than casual, naked-eye, stuff
>such as meteors and aurora), that the large volume of optics discussions
>would be best served by a separate newsgroup, sci.astro.amateur,
>further opening the original sci.astro to discussions and announcements
>of professional observations and theories.
>
>   This new newsgroup would allow the development of a more specific
>FAQ list for telescope making, buying, and operating, while allowing
>a reduction in size of the enormous current sci.astro/sci.space FAQ.
>Also, those who follow the more theoretical and astrophysical sides
>of astronomy would have less material to go through to find what they
>found interesting.  This might attract more professional astronomers
>and physicists to the group, allowing more in-depth discussions.

I would be in favor of this group for exactly the opposite reason.
Although I am interested in discussions about black holes and quasars,
I'm primarily interested in information about what I can see with my
telescope, and how I can see it better.  I would like to have a group
for talking about this kind of stuff, and be able to save the abstract
theoretical discussions for later browsing.

In fact, I'd like to see another group created to encourage posting of
amateur (and professional) observations, perhaps called
"sci.astro.observe".  I like to know what's going up there when I'm not
looking, or when it's cloudy, or just to compare notes with other
observers.  When a comet is in the southern hemisphere, folks
"down under" could tell the rest of us what's happening, and vice-versa.
The same goes for people in other time zones, who could post what
they're seeing while the sun is shining on this part of the world.

I would support both groups.  Anybody else?
--

------------------------------------------------------------------------
Jeffrey L. Cook                            Jeff.Cook@FtCollinsCO.NCR.com
NCR Microelectronics                      uunet!ncrlnk!ncr-mpd!jeff.cook
2001 Danfield Court                             72506.237@compuserve.com
Fort Collins, CO 80525                            Compuserve:  72506,237
------------------------------------------------------------------------
From: hamby@cs.utk.edu (Jeffrey Mark Hamby)
Newsgroups: sci.astro
Subject: reply to sci.astro.amateur
Date: 8 Apr 92 21:55:26 GMT
Distribution: na
Organization: University of Tennessee, Knoxville - CS Department
NNTP-Posting-Host: duncan.cs.utk.edu
Originator: hamby@duncan.cs.utk.edu


My $0.02 on this subject is this:  Please leave sci.astro intact.
I get ~ only 10 messages/day, barely enough to suit me as
it is.  I'd prefer not to have to subscribe to N other news groups
to get what I get now in one group:  A very wide range of interest-
ing, enjoyable comments from a diverse group of folks on a marvelous
range of topics.  What I don't want to read, I can easily skip or
kill; it's occasionally interesting just to see what topics generated
what kind of thread.  Forming more specific groups isn't a bad idea;
I'd just hate to see sci.astro lose some of its charm.

And that's my $0.02.  :^)

Mark
Xref: sparky sci.astro:4831 sci.space:7322 comp.org.eff.talk:3340 talk.politics.space:687
From: jremer@ub.d.umn.edu (Jeremy C. Remer)
Newsgroups: sci.astro,sci.space,comp.org.eff.talk,talk.politics.space
Subject: Stategic Defense System, Accidental Launch System, and related.
Date: 6 Apr 92 23:00:19 GMT
Followup-To: sci.astro
Organization: University of Minnesota, Duluth. Information Services.


I would like to start a discussion about the Stategic
Defense Inititive (SDI) and the Accidental Launch Protection System (ALPS).

I think this will be exciting, and we might even learn something new!  :-)


Here are some questions to help open up a discussion:

Is the United States government spending their money right investing into  
systems such as SDI and ALPS?

What other countries besides the United States that have such systems in the
plans?

The new or more recent updates to SDI and ALPS are the idea of "Smart Rock."
From what I know, "Smart Rocks" have been named after the idea that the
missile that aims at another missile of warhead uses infared and radar
support of collide into its target.  "Dumb Rocks" were those that contained
explosives and accuracy was not as critally, nor was it there.  Another term
I have heard is "Smart Pebbles."  Is that just another name, or is there
another system this is aluding to?


That should be enough to start a discussion.  


-- 
University of Minnesota, Duluth.
Jeremy Remer
E-mail  jremer@ub.d.umn.edu
Newsgroups: sci.astro
From: SCHLEGEL@Zeus.unomaha.edu (Mark)
Subject: Re: Query about "black hole" observations
Organization: University of Nebraska at Omaha
Date: Tue, 7 Apr 1992 16:56:45 GMT
X-News-Reader: VMS NEWS 1.11

In <SCOTT.92Apr5145110@swindle.Berkeley.EDU> scott@swindle.Berkeley.EDU writes:

> 
> % Observations would need to show that a dense central object resides in the
> % center of the object and that its mass exceeds ~ 3 solar masses.
> 
> Isn't the presence of a strong X-ray source another good clue?  I thought that
> was one of the big pro-black-hole points about Cygnus X-1

It is difficult to distinguish the x-ray emission from the accretion disk of
a neutron star from that of a black hole.  Only the mass of the collapsed
object or the existence of a strong mag. field (x-ray pulsars are n.s. that
accrete material only down on the two mag. poles) can decide one way or the 
other.


> 
> Will black holes that are not part of a binary system have enough of an 
> acretion disk to be much of an X-ray source?  (In other words, is it reasonable
> that many black holes might not emit significant X-rays due to the lack
> of an acretion disk?)  Are there other common theoretical mechanisms for X-ray 
> emission from a black hole (perhaps a rapidly changing/rotating magnetic 
> field)?

A totally isolated black hole in space will be invisible for all practical
detection purposes because the b.h. lacks a surface for the thin, accreting
interstellar gas to interact with.  Neutron stars may be detectable as 
very weak UV or x-ray sources since even the thin trickle of protons onto
them in space will result in emission of gamma,x-rays and uv.

Black holes in mass transfer binaries are visible despite the lack of a 
physical surface because the incoming gas is relatively thick and has
a large amount of angular momentum which results in an accreting disk
with viscous friction.  This disk is hot enough to emit x-rays.

I don't know of other mechanisms for x-ray emission from b.hs other than
accretion disks except that the collision of two black holes or the
quantum mechanical evaporation of small black holes (a Stephen Hawkins
theory that unites QM and general relativity) -stellar mass b.hs emit
no detectable radiation with S. Hawkins process.



> 
> Scott Silvey
> scott@xcf.berkeley.edu
From: krod@cbnewsd.cb.att.com (craig.engelhorn)
Newsgroups: sci.astro
Subject: Looking for Crayford Eyepiece Mount
Keywords: Wanted to buy used
Date: 7 Apr 92 23:14:04 GMT
Organization: AT&T

I'm looking for a used Crayford Eyepiece focuser.
If you have one sitting around neglected, collecting dust
and generally not being used I would like to buy it.


Craig Engelhorn
AT&T Bell Laboratories
Naperville, IL
(708)713-5193
cae@iexist.att.com
From: jackz@hpscit.sc.hp.com (Jack Zeiders)
Date: Thu, 16 Apr 1992 19:56:03 GMT
Subject: Re: Fluorite scope for sale
Organization: Hewlett-Packard, Santa Clara, CA
From: dgrimmer@wtcp.DaytonOH.NCR.COM (Dave Grimmer)
Newsgroups: sci.astro
Subject: Re: sci.astro.amateur?
Date: 7 Apr 92 18:03:59 GMT
Reply-To: dgrimmer@wtcp.DaytonOH.NCR.COM (Dave Grimmer)
Organization: Info Res Planning - Dayton, OH

In article <JEFF.COOK.92Apr7103509@pigpen.FtCollinsCO.NCR.COM> Jeff.Cook@FtCollinsCO.NCR.COM (Jeff Cook) writes:
:In article <1992Apr7.001540.20151@mnemosyne.cs.du.edu> jcastner@isis.cs.du.edu (John Castner) writes:
::   I was wondering if anyone else out there saw a need for a new
::newsgroup, devoted to amateur astronomy, and containing primarily
::the many discussions on telescopes and telescope making presently
::found in this group.  I feel that as someone interested in astronomy,
::but not interested observing (other than casual, naked-eye, stuff
::such as meteors and aurora), that the large volume of optics discussions
::would be best served by a separate newsgroup, sci.astro.amateur,
::further opening the original sci.astro to discussions and announcements
::of professional observations and theories.
::
:I would be in favor of this group for exactly the opposite reason.
:Although I am interested in discussions about black holes and quasars,
:I'm primarily interested in information about what I can see with my
:telescope, and how I can see it better.  I would like to have a group
:for talking about this kind of stuff, and be able to save the abstract
:theoretical discussions for later browsing.

I would be very much in favor of a new group geared towards amateur
astronomy.  I get very little from the theoretical discussions and space
craft reports (your milage may vary).  Maybe a sci.astro.amateur could
fill the need that used to be served by "Telescope Making" and "Deep Sky".
The new group would also be a more appropriate place for club newsletters
and announcements of club events.

Does anbody have any idea of how many people subscribe to sci.astro?

-- 
Dave Grimmer
email: Dave.Grimmer@DaytonOH.NCR.COM    CompuServe: 70412,2455
From: terry@venus.sunquest.com (Terry R. Friedrichsen)
Newsgroups: sci.astro
Subject: X-based satellite tracking programs
Summary: OK, I'll do it myself
Keywords: satellites   tracking   X Window System
Date: 9 Apr 92 21:54:41 GMT
Followup-To: sci.astro
Organization: Sunquest Information Systems, Tucson

A while back I posted a query requesting information on satellite tracking
programs for the X Window System.  Got absolutely ZILCH in response; do
ALL of you folks use (ugh!) PCs or Macs?  Oughta change the name of this
group to sci.underprivileged ;-).

So here's the next big question:  anybody got SOURCE CODE for a satellite
tracker that runs on a PC in some reasonable language?  One that reads in
the usual Keplerian elements and spits out a nice (where nice is relative)
picture of the Earth with the satellite track superimposed?

If you do, and can legally give me a copy, please let me know.  I'll take
the best-sounding offer and see if I can convert it to run under X (provided
I can figger out the weirdness in the way graphics is done on the PC ...).
If successful, the result will be made available to the net (in source form,
of course!).

AdTHANKSvance.

Terry R. Friedrichsen

terry@venus.sunquest.com  (Internet)
uunet!sunquest!terry      (Abusenet)
terry@sds.sdsc.edu        (alternate address; I live in Tucson)
Xref: sparky sci.astro:4947 rec.photo:7001
From: dbell@cup.portal.com (David J Bell)
Newsgroups: sci.astro,rec.photo
Subject: Re: TI Light-Frequency Chip
Date: Thu,  9 Apr 92 21:24:07 PDT
Organization: The Portal System (TM)
Distribution: world


>I've gotten a sample of the TI TSL220 Light to frequency converter chip,
>if anybody is interested.  I've got it hooked up to a microcontroller
>chip and can measure the output.  So far I've just tried it in my office
>and don't quite know its sensitivity range.

Boy! If that isn't a let-down after a subject line
like "TI Light-Frequency Chip". And I had visions
of a whole new meaning to "DC-to-Daylight"!!

(Actually, it sounds like an interesting device. Let us
know when you have tested it further.)

Dave
Newsgroups: sci.astro
From: fischer@physun.physics.mcmaster.ca (Phil Fischer)
Subject: Re: Query about "black hole" observations
Organization: Dept. of Physics, McMaster Univ., Hamilton, Ontario, CANADA
Date: Mon, 6 Apr 1992 03:47:50 GMT

In article <BM6x7K.7GK@world.std.com> rsilver@world.std.com (Richard Silver) writes:
>
>We read many articles with statements such as "Professor Blank believes 
>a black hole may reside in the center of this object". 
>
>I have two queries: 
>(1) What will be required to convince the majority of the scientific
>community that a black hole has actually been observed? 
>(2) When might this occur?
>
> 

I think the majorit of the astronomical community (I have no actual 
statistics) already believes in the presence of black holes in a few systems
specifically in X-ray binaries.

Phil

Newsgroups: sci.astro
From: schinder@leprss.gsfc.nasa.gov (Paul J. Schinder)
Subject: Re: sci.astro.amateur?
Reply-To: schinder@leprss.gsfc.nasa.gov
Organization: Goddard Space Flight Center
Date: Wed, 8 Apr 1992 15:48:06 GMT

In <1250@wtcp.DaytonOH.NCR.COM> dgrimmer@wtcp.DaytonOH.NCR.COM (Dave Grimmer) writes:

>I would be very much in favor of a new group geared towards amateur
>astronomy.  I get very little from the theoretical discussions and space
>craft reports (your milage may vary).  Maybe a sci.astro.amateur could
>fill the need that used to be served by "Telescope Making" and "Deep Sky".
>The new group would also be a more appropriate place for club newsletters
>and announcements of club events.

I don't see the need.  sci.astro isn't a particularly large newsgroup
by USENET standards.  Most people who've complained about the size of
the group would be better served if they switched newsreaders or
convinced their site admin to get a better one.  I use nn, and it
works just fine for selectively reading much larger groups than this.
Even rn allows selective reading, although not as easily.

One of the common fallacies on USENET is "topic X isn't discussed,
therefore we need a group for topic X". In reality, if topic X isn't
discussed somewhere, there's no need for a group, as people who manage
to create such groups soon find out.  If people want to post club
newsletters and club events, post them here, but use appropriate
geographic distributions.  If such traffic is large enough and
persists, *that* is reason to create a new group.  The mere existance
of a group almost never generates the traffic to fill it; significant
traffic must already exist (usually, there have been a few exceptions
in my time on the net) for successful newsgroups to be spun off.

>Does anbody have any idea of how many people subscribe to sci.astro?

According to the latest "arbitron" figures (released monthly in news.lists):

        +-- Estimated total number of people who read the group, worldwide.
        |     +-- Actual number of readers in sampled population
        |     |     +-- Propagation: how many sites receive this group at all
        |     |     |      +-- Recent traffic (messages per month)
        |     |     |      |      +-- Recent traffic (kilobytes per month)
        |     |     |      |      |      +-- Crossposting percentage
        |     |     |      |      |      |    +-- Cost ratio: $US/month/rdr
        |     |     |      |      |      |    |      +-- Share: % of newsrders
        |     |     |      |      |      |    |      |   who read this group.
        V     V     V      V      V      V    V      V
  75  68000  1387   82%   502  1391.8    22%  0.03   3.2%  sci.astro

Note that this works out to under 20 messages per day on average.

>-- 
>Dave Grimmer
>email: Dave.Grimmer@DaytonOH.NCR.COM    CompuServe: 70412,2455
--
--------
Paul J. Schinder
NASA Goddard Space Flight Center
schinder@leprss.gsfc.nasa.gov
Newsgroups: sci.astro
From: jdishaw@acme.claremont.edu
Subject: Re: sci.astro.amateur?
Organization: Pomona College
Date: 8 Apr 92 22:19:29 PDT

In article <1992Apr8.094534.25396@news.Hawaii.Edu>, joe@montebello.NoSubdomain.NoDomain (Joe Dellinger) writes:
> 
> 	I would dearly like to see a "sci.astro.urgent". When I'm busy I
> don't have the time to follow sci.astro, because the volume is too large.
> I always wonder what once-in-a-lifetime astronomical opportunity I might
> be missing. Certainly the local newspapers here wouldn't carry any such
> thing!
> 
> 	Sci.astro.urgent should have VERY low volume; it would only carry
> urgent reports for stuff like supernovas, novas, new bright comets, really
> _exceptional_ auroras, unexpectedly good meteor showers, etc, that would be
> of wide interest AND of a short-lived nature. I would expect very few postings
> in it, but I would also expect to poll it often "just in case".
> 
> 	Comments?
> 
>      /\    /\    /\/\/\/\/\/\/\.-.-.-.-.......___________
>     /  \  /  \  /Hawaii Institute of Geophysics, Honolulu\/\/\.-.-....__
> ___/    \/    \/Joe Dellinger, Internet: joe@montebello.soest.hawaii.edu\/\.-.__

I think this an *excellent* idea.  It could be a moderated list like
news.announce.important.  In fact it can also be used to distribute telegrams
with all those handy announcements.  Heck I'd even volunteer to be one of the
moderators.

-james dishaw
JDISHAW@POMONA.CLAREMONT.EDU
Newsgroups: sci.astro
From: jcm3r@faraday.clas.Virginia.EDU (John Carl Martin)
Subject: Help finding NASA GIF files
Organization: University of Virginia
Date: Mon, 13 Apr 1992 01:58:31 GMT

On Sunday night, I was FTPing to the ames.arc.nasa.gov to download
some GIF files that I had picked out.  I expected to find these
files in the directory /pub/SPACE/GIF but the directory was empty,
except for the INDEX file which read:
       total: 0

Only two days before, the files that I had wanted where in this directory    
along with many others.  The files in the /pub/GIF directory are not the
ones that I am looking for.  Does anyone out there know what happened to
all those GIF files?  Thanks.

John C. Martin
  jcm3r@virginia.edu


Newsgroups: sci.astro
From: lattis@sal.wisc.edu (Jim Lattis)
Subject: Re: when is the dark side of the moon visible to the naked eye?
Summary: ancients knew moon was spherical
Organization: Space Astronomy Lab, Madison WI
Distribution: sci
Date: Tue, 7 Apr 1992 14:10:51 GMT

you are right in attributing the glow of the dark
side of the moon to earthlight.  the phenomenon is
most evident near new moon, which naturally corrsponds
to "full earth" as seen from the moon. in english, one
traditional formulation of the effect is "the old moon
in the new moon's arms".  it had been noticed since
antiquity, but the correct explanation was (first? i'll
check) given by Galileo in his Siderius Nuncius of 1610.

in answer to your other question, that the moon is spherical
in shape was known to ancient Greek astronomers.  it is a
simple deduction from the shape of the terminator, but was
also believed to be true a priori because, according to
Plato & Aristotle, all celestial bodies are spherical since
the sphere is the most perfect geometric solid etc.

Newsgroups: sci.astro
From: goldader@uhunix.uhcc.Hawaii.Edu (Jeffrey D. Goldader)
Subject: Re: sci.astro.amateur?
Summary: Don't distribute IAU Circulars
Organization: University of Hawaii
Date: Thu, 9 Apr 1992 21:22:00 GMT

In article <1992Apr8.221929.1@acme.claremont.edu> jdishaw@acme.claremont.edu writes:
>In article <1992Apr8.094534.25396@news.Hawaii.Edu>, joe@montebello.NoSubdomain.NoDomain (Joe Dellinger) writes:
>> 
>> 	I would dearly like to see a "sci.astro.urgent". [...]
>> I always wonder what once-in-a-lifetime astronomical opportunity I might
>> be missing. Certainly the local newspapers here wouldn't carry any such
>> thing!
>> 	Sci.astro.urgent should have VERY low volume; it would only carry
>> urgent reports for stuff like supernovas, novas, new bright comets, really
>> _exceptional_ auroras, unexpectedly good meteor showers, etc, [...]
>
>I think this an *excellent* idea.  It could be a moderated list like
>news.announce.important.  In fact it can also be used to distribute telegrams
>with all those handy announcements.  Heck I'd even volunteer to be one of the
>moderators.

Uh, I assume you're talking about the IAU Circulars?  *They aren't 
supposed to be given away on networks.*  The people who make 
the circulars need the money from subscriptions to cover their 
costs.  It is not a big operation.  Give them away, and people 
don't subscribe, and out of business the Circulars go.

Jeff Goldader			  Disclaimer:  They don't know what I say,
goldader@uhunix.uhcc.hawaii.edu	               I don't care what they think,
				               and we're all happy that way.
Newsgroups: sci.astro
From: monta@image.mit.edu (Peter Monta)
Subject: Extended and point objects in astrophotography
Organization: MIT Advanced Television Research Program
Date: Fri, 17 Apr 1992 08:49:31 GMT

I've been puzzling for awhile over the difference between
extended and point objects, especially the point at which one
turns into the other.  It seems clear that the exposure
resulting from an object spanning a large part of the field
depends only on focal ratio, and that resulting from a star
only on entrance pupil diameter; this is pointed out in several
nice books I've been reading:  Liller and Mayer's "The Cambridge
Astronomy Guide", Covington's "Astrophotography for the Amateur",
and Wallis and Provin's "A manual of advanced celestial
photography".

Fine.  At what point does a small object exposure stop depending
on focal ratio?  The only remaining quantity is the spot size
of the optics/film system, so the answer must be "on the order
of spot size", but why is this?  What is really happening?

Finally, the question I'd like to be able to answer is "do I
improve my SNR for stars by stopping down (ignoring decrease
in aberration, and assuming equal exposure)?"  I shoot in a very
light-polluted location, and any extra margin is welcome
(I'm also using a red filter, which helps considerably).

Thanks,
Peter Monta   monta@image.mit.edu
MIT Advanced Television Research Program
Newsgroups: sci.astro
From: jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins)
Subject: Re: comet approaching?
Organization: University of Illinois at Urbana
Date: Fri, 17 Apr 1992 18:00:53 GMT

edwards@bgsu.edu (Bruce Edwards) writes:

>From what I've read it would be *extremely* difficult to actually track
>and subsequently intercept an incoming astronomical object.  Why?

>1. Very high velocities are involved (an understatement).
>2. One which was headed "right at us" would not show apparent
>   motion against the background of stars but would appear
>   star-like until it was too late.

>Yes? No....

>edwards@andy.bgsu.edu
	
	Actually, most asteroids are discovered a long way from Earth.  Then
you calculate the orbit, run it through a long term simulation and decide 
whether it's going to hit Earth or not.  The idea of detecting asteroids while
they are on their way in and quickly destroying them is more the idea of the
weaponeers/mass media than a scientific concept.  It's much more practical
to project the danger a few years ahead of time and 'tweak' the orbit while
the asteroid is very far out.
	Remeber too that Orbital Mechanics doesn't use many straight lines.
An asteroid on an intercept trajectory isn't moving 'straight at us' until
shortly before it hits.  

			Josh Hopkins

		Josh Hopkins 
Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave