HDTenEightyP/NetNews huggingface dataset:
From: wing@canada.ceo.dg.com (Brian Wing)
Subject: Re: Typo in Meeus' "Astronomical Algorithms"
Date: Thu, 13 Aug 92 17:39:49 GMT
Organization: Data General (Canada) Inc.

randolph@est.enet.dec.com (Tom Randolph) writes:
: 
: Jean Meeus' new book, "Astronomical Algorithms", has a typo. The error is on
: page 139, in the equation for pi, the longitude of Earth's perihelion. The
: second term, 0.71953T should be 1.71953T. Compare the numbers to those in
: Chap. 30, page 200. They should match exactly. Page 200 has the correct
: numbers.
: 
: Unfortunately, this error is in the C software that you can buy with the
: book. I don't know about the other language versions. It shouldn't make any
: huge difference in results, in fact it might not even be noticable except
: maybe over thousands of years.
: 
: -Tom R.   est.enet.dec.com!randolph

I noticed another tiny typo in the C software.
In MOONPOS.C, in the array MoonTermB, the second to last line reads:
{4,-1, 0, 1, 115}
when it should be:
{4,-1, 0,-1, 115}
	 ^ note the missing minus sign.
In the book, it's OK.

I already EMailed this nit to Jeffrey Sax.

-- 
Brian Wing                         Software Support Critter
Data General (Canada) Inc.
130-13151 Vanier Pl., Richmond     dotdot: brian_wing@canada.ceo.dg.com
B.C., Canada V6V 2J2               "Hello?": +1 604 273 5100
Organization: Penn State University
Date: Thu, 13 Aug 1992 09:52:28 EDT
From: <BWF2@psuvm.psu.edu>
Newsgroups: sci.astro
Subject:    Perseids ?

    I am one who enjoys just looking at events and I don't understand
    what the magnitudes are for viewing. But I do enjoy seeing
    "shooting stars" and other phenomena. So, on 8-11-92 between the
    hours of 10:30pm est and 11:30pm est I went out to look for the
    Perseids. My very first "one" was what I consisder very bright.
    It appeared to be mostly an orange flame color with a very nice
    trail. I saw 4 others that were more of a whiteish color with some
    nice trails. The other 6 I saw were very faint and if I wasn't
    looking at that section of the sky I wouldn't have seen them.
    I've been reading the posts here on the Perseids and noted that
    people will say they saw 5 Perseids and 2 others. How do I know
    if I saw Perseids or not? The 11 that I saw all were moving
    accross the sky in mostly a west/south movement. To see these, I
    was sitting on my porch looking almost straight up. Sorry if this
    post is very novice like, but thats what I am. Thanx for any info!
   Brian
    Oh yeah, I live in Centre Hall, Penna which is basically in the
    center of Pennsylvania.
Newsgroups: sci.astro
From: pbrown@uwovax.uwo.ca
Subject: PERSEID STORM OVER EASTERN EUROPE!
Organization: University of Western Ont, London
Date: Sun, 16 Aug 1992 21:27:31 GMT

PERSEID STORM IN EASTERN EUROPE...

Data from Hungarian meteor observers and several radio amateurs in the USA
and Finland have revealed the strong possiblity that the expected strong 
return of the Perseids in 1992 *did* take place. The observations in question
suggest 19-20 UT on Aug 11/12 as the time the outburst occurred. This is 
several hours earlier than predicted since the predicition was based on
the assumption that the activity which took place over Japan in 1991 would
recur again at the same position in the Earth's orbit, namely at 138.86 
(1950.0). As was pointed out by Marsden if the the shower recurred at 
precisely the node of P/Swift-Tuttle the storm would occur several
hours before the 22-23 UT Aug 11/12 shortly after 19 UT, as seems to have
happened. This is **very** strong evidence to suggest that P/Swift-Tuttle is
very nearby and searches for the comet should certainly go into high gear.
This outburst occurred at 138.74 (1950.0) and if it recurs again within
a few tenths of degrees of this position then we can expect a nice meteor
shower in 1993 on Aug 12 at about 1-2 UT. This means North America might
catch some of the activity early in the evening and the moon will be only
4 days from new!! 
Since many details are still missing it is *imperative* that observers either
radio or visual who have data in the interval 18-20 UT report it as soon as
possible so a complete picture of what happened can be constructed.
Further details can be found on IAUC 5586.

*****************************************************************************
Peter Brown   peter@canlon.physics.uwo.ca
North American Section - International Meteor Organization (IMO)
*****************************************************************************
From: Richard.Mathews@West.Sun.COM (Richard M. Mathews)
Newsgroups: sci.astro
Subject: Re: Quasars: near versus far
Date: 12 Aug 92 23:41:05 GMT
Distribution: sci
Organization: Sun Microsystems, Inc.
NNTP-Posting-Host: smaug.West.Sun.COM

njzy@vax5.cit.cornell.edu (T. Joseph Lazio, Cornell University) writes:

> At the risk of displaying considerable ignorance, I have always 
> understood the cosmological constant to be an integration constant.

Not really.  Einstein's wanted a field equation of the form
	G' = 8*pi*T
where G' is a measure of curvature of space-time, T is stress-energy,
and the 8*pi is there by convention.

Make the following assumptions:

	1. like T, G' must be symmetric and rank 2
	2. G' must have zero divergence as does T
	3. G' must be linear in R
	4. G' must be constructed from R and g and nothing else
	5. G' must vanish when spacetime is flat

You will uniquely arrive (apart from a multiplicative constant)
at Einstein's original 1915 field equation in which G' = G where
G[ab] = R[ab] - R*g[ab]/2.  No other way of constructing G' from R and
g will satisfy the above assumptions.  The multiplicative constant is
determined by requiring the theory to agree with Newtonian gravitation
in the Newtonian limit.

In 1917, Einstein decided that he had to remove at least one of the above
assumptions to be able to get a field equation which admits a static
cosmology.  You can't relax #1 on mathematical grounds, and you can't
get rid of #2 on dynamic grounds (properties inherent in G must force
local conservation of energy; otherwise, there aren't enough degrees
of freedom left in G to allow interesting dynamics).  Eliminating #3
would vastly complicate the theory, so by Occam's razor we won't do
that unless we have to.  Since Einstein was looking for a geometric
theory, #4 is required.  All Einstein could do is remove #5.  With this
removed, G' is no longer a unique function of R and g.  Adding anything
proportional to g to a valid G' gives another valid G'.  Thus we get the
cosmological constant, setting
	G' = G + lambda*g.

> I thought it appeared in the derivation of the relationship between H, 
> Hubble's constant, and \Omega, the density parameter.

Though the cosmological constant appears in that relationship, that
isn't where it comes from.  It comes from the above change to the field
equations themselves.  Back in 1917 it was an ad hoc change to think
that the vacuum could be anything but flat.  Now with zero point energy
of the vacuum being part of the standard thinking, it might be natural
to relax assumption #5 today and introduce the cosmological constant,
but it wasn't then.

Richard M. Mathews			Lietuva laisva = Free Lithuania
Internet:   richard@locus.com		Brivu Latviju  = Free Latvia
UUCP:	    ...!uunet!lcc!richard	Eesti vabaks   = Free Estonia
MIL/BITNET: richard%lcc@UUNET.UU.NET	        WE  DID  IT!!!
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 August
Organization: University of Lethbridge
Date: 17 Aug 92 05:36:54 GMT

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 229, 08/16/92
10.7 FLUX=136.6  90-AVG=126        SSN=133      BKI=2242 2102  BAI=008
BGND-XRAY=B3.6     FLU1=5.5E+05  FLU10=1.2E+04  PKI=2243 2222  PAI=010
  BOU-DEV=010,017,051,018,015,008,004,010   DEV-AVG=016 NT     SWF=00:000
 XRAY-MAX= C2.9   @ 1358UT    XRAY-MIN= B3.3   @ 1142UT   XRAY-AVG= B4.9
NEUTN-MAX= +005%  @ 0245UT   NEUTN-MIN= -001%  @ 1200UT  NEUTN-AVG= +0.7%
  PCA-MAX= +0.2DB @ 1405UT     PCA-MIN= -1.4DB @ 2110UT    PCA-AVG= -0.0DB
BOUTF-MAX=55262NT @ 1315UT   BOUTF-MIN=55209NT @ 1713UT  BOUTF-AVG=55247NT
GOES7-MAX=P:+104NT@ 1837UT   GOES7-MIN=N:-018NT@ 0918UT  G7-AVG=+076,+042,+009
GOES6-MAX=P:+115NT@ 2122UT   GOES6-MIN=E:-009NT@ 0858UT  G6-AVG=+085,+005,+031
 FLUXFCST=STD:140,140,137;SESC:145,145,140 BAI/PAI-FCST=015,020,015/015,020,015
    KFCST=3235 5223 4445 5322  27DAY-AP=008,011   27DAY-KP=2201 3332 1222 3432
 WARNINGS=*SWF
   ALERTS=
!!END-DATA!!
Newsgroups: sci.astro,rec.radio.shortwave
From: pbrown@uwovax.uwo.ca
Subject: UNUSUAL PERSEID ACTIVITY?
Organization: University of Western Ont, London
Date: Thu, 13 Aug 1992 20:15:39 GMT

Having received a few initital reports on the
1992 Perseids from Aug 11/12 I have one further request for observers. 
There is a possiblity that something unusual took place in the hours 
before the predicted new maxima at 22-23 UT, Aug 11. If anyone made some radio 
observations or visual observations in the interval 15-21 UT, Aug 11 I would 
be extremely appreciative of receiving a report to clarify the situation 
during those hours.

************************************************************************
Peter Brown     peter@canlon.physics.uwo.ca
North American Section - International Meteor Organization
From: aabdalla@pollux.usc.edu (AAA)
Newsgroups: sci.astro
Subject: Closed, open, flat???
Date: 19 Aug 1992 13:26:39 -0700
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: pollux.usc.edu

I just started reading Riordan and Schramm's book on dark matter,
the universe, and stuff (_Shadows of Creation_), and I already have
a couple of questions - I am not a physicist or a cosmologist (I
could tell you a few things on computers though :-)).

Within the first 30 pages, R & S describe this theory of a "flat"
universe which matches very well with the "inflationary" universe
hypothesis of Guth.  As I understand it, R & S also feel that most
physicists believe that the universe is flat, which in symbols would
mean that Omega (critical density over actual density) is 1.  
Of course there is still a huge search on to prove this, since our
measurements yield Omega=0.1 or so, right?

If in a closed universe, we could travel in a "straight" line and 
end up back where we started, and in an open universe we couldn't...
then what happens in a flat universe?  I'm not sure if I understood
R & S correctly, but is it accurate to say that the inflationary
universe scenario starts out with Omega less than 1 (so the universe
is closed), then as it "inflates", Omega rapidly approaches 1 so
that expansion forever continues BUT the universe remains closed??

Wow!  That's what I like about layman physics: I can ask all these
ill-posed questions with no clue whatsoever and sound semicoherent...

No, but really, any help on this would be appreciated - especially
if you reply by email:  aabdalla@pollux.usc.edu

AAA
Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave
From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Solar Geophysical Data Broadcast for 13 August
Organization: University of Lethbridge
Date: 14 Aug 92 04:18:14 GMT

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 226, 08/13/92
10.7 FLUX=128.9  90-AVG=125        SSN=079      BKI=0111 1422  BAI=006
BGND-XRAY=B3.5     FLU1=7.4E+05  FLU10=1.1E+04  PKI=2122 3333  PAI=010
  BOU-DEV=002,005,008,009,008,044,010,017   DEV-AVG=012 NT     SWF=00:000
 XRAY-MAX= C1.6   @ 0417UT    XRAY-MIN= B3.2   @ 1559UT   XRAY-AVG= B5.1
NEUTN-MAX= +004%  @ 1725UT   NEUTN-MIN= -002%  @ 0135UT  NEUTN-AVG= +0.6%
  PCA-MAX= +0.3DB @ 1515UT     PCA-MIN= -0.1DB @ 2340UT    PCA-AVG= +0.0DB
BOUTF-MAX=55269NT @ 2356UT   BOUTF-MIN=55214NT @ 1734UT  BOUTF-AVG=55247NT
GOES7-MAX=P:+124NT@ 1925UT   GOES7-MIN=N:+002NT@ 1330UT  G7-AVG=+080,+037,+008
GOES6-MAX=P:+134NT@ 1925UT   GOES6-MIN=E:-008NT@ 0732UT  G6-AVG=+091,+004,+029
 FLUXFCST=STD:120,115,110;SESC:115,105,100 BAI/PAI-FCST=005,005,010/010,010,010
    KFCST=3332 2222 3332 2222  27DAY-AP=008,005   27DAY-KP=3301 2222 1211 1221
 WARNINGS=*SWF
   ALERTS=**245STRM:0103-0718UTC
!!END-DATA!!
Newsgroups: sci.astro
From: ce062@cleveland.Freenet.Edu (Joel B Stuckey)
Subject: Re: conjunction predictions
Reply-To: ce062@cleveland.Freenet.Edu (Joel B Stuckey)
Organization: Case Western Reserve University, Cleveland, OH (USA)
Date: Sun, 16 Aug 92 00:21:48 GMT


In a previous article, gill@physics.ubc.ca (Arnold Gill) says:

>     Just how easy is it to predict conjunctions?  I had been asked recently
>     how often the triple conjunction of Mars, Venus, and Jupiter (last year)
>     occurred, and had little fits trying to figure this out based on angular
>     differences measured from the Sun, even assuming circular, coplanar 
>     orbits.
>
>     What is the proper method of doing this?  Matching synodic periods?
>     Orbital integration?
>
>Arnold Gill

     Not trying to be a smartass or anything but the easiest way to check
for conjunctions is to use Voyager on your nearest Mac. It will search for
future as well as past conjunctions, and you can set the field to a 
specific size. Hope this helps.


>
-- 
Joel B Stuckey     STUCKE98@SNYBUFVA.CS.SNYBUF.EDU
                   CIS 73177,3460
                   Buffalo State College, Buffalo NY
Newsgroups: sci.astro
From: gliba@scivax.stsci.edu
Subject: Train vs. Trail
Organization: Space Telescope Science Institute
Distribution: na
Date: Thu, 13 Aug 1992 22:08:58 GMT




Train vs. Trail


   After reading the postings of Perseid observations. It was interesting
to note that even some of the experianced observers didn't use the correct
terminology for the use of the word trail. The word trail was often used
instead of the correct word train, to discribe the ionized wake left by a
meteor. All meteors leave a trail. The trail is the path the meteor takes.
Not all meteors leave a train. The trail is gone after the meteor burns out,
but the train can last for seconds, and even several minutes for a bright
Fireball. I once saw a -12 magnitude Fireball in November of 1985, while I  
was observing Halley's Comet, that left a train that lasted fifteen minutes!
   I know this might seem nit picky to some, but I think it is important to 
use the correct words when describing a meteor train or trail.



G.W. Gliba - 'I would rather see starlight than streetlights'
From: hmai@namu01.gwdg.de (Holger Mai 29122129)
Newsgroups: sci.astro
Subject: Re: Nova Cygni 1992 Update
Date: 20 Aug 92 16:11:26 GMT
Distribution: na
Organization: Georg-August-Universitaet Goettingen, Germany

In article <1992Aug19.164416.1@scivax.stsci.edu> gliba@scivax.stsci.edu writes:

>    The nova continues to slowly fade. Last night at 4:30 UT using
>  the AAVSO (b) chart 2027+52 I estimated it to be 8.7 magnitude.

In IAUC 5552 D.Hanzel & F.Hroch of N.Copernicus Obs. at Brno report
the following CCD magnitudes for Nova Cygni:

Jul.Dat.     Date (UT)   Mag.   max.err.

2448794.447  06-20.947   9.16  .03

2448801.388  06-25.888   9.21  .03

2448802.416  06-28.916   9.31  .03


You should better add the date and time of Your observation to Your
estimated magnitudes. Without any error it is impossible to 
compare Your results with other observations.

Please add these three things (date, time, error) to Your
magnitudes next time. Thank You !!!

                                    *** Holger ***
--
 
 -----------------------------------------------------------------------------
 | Holger Mai | Waldweg 4,             | E-Mail: hmai@namu01.gwdg.de         |
 |            | D-3400 Goettingen      |         hmai@go.ovum.ka.sub.org     |
 |            | Tel. 49-(0)551-42199   | Fido:   Holger Mai @ 2:245/45       |
 -----------------------------------------------------------------------------
Newsgroups: sci.astro
From: benge@sol.acs.unt.edu (Benge Raymond Doyle)
Subject: Re: the moon
Organization: University of North Texas
Date: Mon, 17 Aug 1992 15:53:55 GMT

rsb@mcc.com (Richard S. Brice) writes:

>In article <Bt3EsB.6q2@usenet.ucs.indiana.edu>, turner@bigbang.astro.indiana.edu (George Wm Turner) writes:
>> 
>> anyways, this friction robs the earth of rotational energy and slows
>> the earth's spin; (the length of an earth day lengthens by about 
>> 0.002 second per century.) but the total angular momentum of the 
>> earth-moon system must be conserved causing the moon to move farther
>> out.  to put it another way, since there is less angular momentum in a
>> slower spinning earth at the center, a way to get more angular
>> momentum is to move the mass of the moon farther away thus keeping
>> the total amount of angular momentum constant.  (this theory of tidal

>How does the moon know that it's supposed to move further away from the
>earth just because the earth is slowing down?

It doesn't.  It moves outward because IT is speeding up.  The same forces
which cause the earth to experience the tidal slowing of its rotation also
cause the moon to speed up in its orbit (equal and opposite forces, and all
that).  As the moon speeds up, it moves to a farther orbit and slows down.
Angular momentum is conserved.

		Ray Benge
From: rushford@novax.llnl.gov
Newsgroups: sci.astro
Subject: Laser Guide Star observations
Date: 12 Aug 92 19:44:45 GMT

Today 8/12/92 12:01-4:00 AM
 the Laser Guide Star (LGS) beam was visable over Livermore, CA.
The weather was governing when the beam was on... clouds delayed the start
and dictated the shutdown and start again....-- I viewed the beam 4.4 KM 
from the LGS launch sight. When clouds drifted into the beam they glowed
brightly and in layers. Often the clouds were not visable unless the beam
shinned through them. The most visable property of the beam is its Rayliegh
scattering. The clouds glow was always within the Rayliegh scatter portion
of the beam. Its easy to judge the ending of the Rayliegh scatter by eye, it
fades off gradually to zero by eye. The quide star portion of interest is
off the end of and removed from the Rayliegh scattering. It is the result of
Sodium, at 90 KM elevation, which is made to floress via the 5896 nm laser 
light. The guide star should appear as a line 0.5 degrees long at a tip angle
of about 3 degrees from vertical for my location. The estimate is the guide
star should be removed from the end of the Rayliegh scatter by 180 Minuts.
It is also estimated that the guide star should be 14th magnitude, however,
I saw something using binoculars whith the proper position and size.
 I estimate the object to be 5-6th magnitude..... by eye...
I set up LLNL borrowed 8 inch celestron telescope and a micro channel plate
intensified CCD camera and pointed it at the object mentioned above. While
in radio contact with the LGS sight we viewed that the glow "blinked" @ 1 HZ 
on and off in responce to the laser wavelength changes.... The event was
video taped.. The object overfilled the camera field of view by about 3x.

The claim is; this glow is sodium and thus is the laser guide star.....

I will maintain a schedual for LGS events in my .plan file...
You may finger rushford@128.115.45.27 to view it..

Get up and look at it,,, Looks neet specially with lightning in the background
from the Serias T storms and when the beam hits a cloud it's bright....


Michael C. rushford@novax.llnl.gov or

michae1222@aol.com

office  (510)-423-2037

Newsgroups: sci.astro
From: STONE@Zeus.unomaha.edu (Travis R. Stone)
Subject: Re: Calculating Planetary Positions
Organization: University of Nebraska at Omaha
Date: Thu, 20 Aug 1992 22:59:14 GMT
X-News-Reader: VMS NEWS 1.11

Milo:

  My advice to you is to scare up a copy of Jean Meeus' nifty
  tome, "Astronomical Formulae for Pocket Calculators"---at
  least, I THINK that's the title; if nothing else, just go
  on the basis of the name "Jean Meeus" when you talk to your
  local book dealer.

  Meeus shows you how to do positional calculations using
  principal perturbations of the outer planets, and how to
  correct for crap like nutation, precession, and refraction.
  The results I get with code written in Pascal (with Double
  Precision) and run on a VAX are good to about 1 arc-minute
  or better for the Sun, Mercury, Venus...Uranus and Neptune;
  Meeus gives you rough formulae only for Pluto, since the
  wobbly little bastard's orbit is so hard to pin down (i.e.,
  there has been no good "theory" derived for Pluto's motion
  yet).

  Hope this helps.

  P.S.--- I know for a fact it's available in paperback.

  T.R. Stone
  University of Nebraska-Omaha
From: reynolds@panix.com (Brian Reynolds)
Newsgroups: sci.astro
Subject: inexpensive equitorial mounts
Summary: Where can I find an inexpensive equitorial mount?
Date: 16 Aug 92 03:42:49 GMT
Organization: PANIX Public Access Unix, NYC

I am currently trying to decide between building a telescope (6-8"
Newtonian) and buying a commericially available telescope.  The
biggest stumbling block to building a telescope is that I can't find
an affordable equitorial mount.

Meade's Starfinder mount cost more than a complete 8" Starfinder
system.  Celestron's Super Polaris isn't much better (price wise).
University Optics has an ad in Sky & Telescope for an equitoral head
that can be put on a pier or a tripod made of 2x4's, but according to
the insert I got with the catalog in June they have cancelled this
item.  I'm going to call them on Monday to see if the insert I have is
older than their ad.

Can anyone point me towards other suppliers of equitorial mounts?
What do people think of the quality, durability and steadiness of the
above mentioned mounts?

Thanks in advance.

-- 
Brian Reynolds
reynolds@panix.com
NAR# 54438
IPMS# 30162
From: newberry@newton.as.arizona.edu (Mike Newberry)
Newsgroups: sci.astro
Subject: Re: Anthropic Principle?
Date: 22 Aug 92 00:20:50 GMT
Organization: University of Arizona, Tucson, AZ

In article <gill.714437283@physics.ubc.ca> gill@physics.ubc.ca (Arnold Gill) writes:
>clarke@acme.ucf.edu (Thomas Clarke) writes:
>
>>What do you netters think of the anthropic principle? (AP for short)
>>That is the idea that the universe is the way it is because
>>we are here to observe it.  If it were different we wouldn't
>>be here.
>
>     I think it is something to seriously consider.  I find this especially
>     true in those cases where someone says "this could never happen over the
>     lifetime of the Solar System", and throws out a theory because of that.
>     Perhaps the odds are something like that, and perhaps life evolved on 
>     Earth because our solar system was the one in a billion with the right
>     conditions.  Observing here, we can only see the one positive case, not
>     the billion negative ones.  Perhaps life is extremely unlikely, but it
>     did happen at least once -- here.
>
>--
>Arnold Gill --- astrophysician trainee in exile             gill@physics.ubc.ca


I look at this whole idea as being something of a nonsequitur--what's the
point?  Does this lead to anything?  I think we have to be especially careful
about this kind of... well, for lack of a better word, "religion". The 
direction of causality in the use of "because..." bothers me a great deal.
If you reversed the sentence, then it would destroy the anthropic principle
but make a heck of a lot more sense to me; to wit, "We are here to observe
the universe because of the way it is", an obvious fact. As stated, the AP
can't help but carry some baggage about an omnipotent entity created in
Man's own image who cares more about humankind than about the rest of the
universe.  In short, I have no use for the Anthropic Principle.

Mike Newberry
Newsgroups: sci.astro