NetNews Usenet Archive 1992 #20/NN_1992_20.iso/spool/sci/astro/9596

Text File | 1992-09-10 | 6.1 KB | 122 lines

Newsgroups: sci.astro
Path: sparky!uunet!gatech!darwin.sura.net!spool.mu.edu!agate!linus!linus.mitre.org!mandolin!chaloux
From: [e-mail] (Dave Chaloux)
Subject: Almost full moon - Who cares?
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Reply-To: [e-mail] (Dave Chaloux)
Organization: The MITRE Corporation, McLean, Va
Date: Thu, 10 Sep 1992 21:57:21 GMT
Lines: 109

I suspect like many of you, I go through monthly cycles. As full moon
approaches I grow more and more restless, desperate, etc. I woke up
just before 4:00 a.m. this morning (9/10/92) and decided I just had to
observe something. CAS rides high in the sky to North at this time of
night and I figured that I could at least look up some open clusters.
It wouldn't be great but hey, it might keep me sane for another day or
two.

I walked out to the Observatory, popped the hood and fired up the 20".

M103 is a nice bright triangular grouping with 3 bright stars marking
the corners and a beautiful deep orange star in the cluster. It is
reasonably rich but not overly so. It is about 7' in diameter and was
easy in the 9x60 finder. It has been compared to an arrowhead by some.

Tr-1 is visible in the same field when I use my 40mm University 7-70.
Nothing like having the right eyepiece for the job. It lies about 40'
away from M103 to the North. This cluster is very conspicuous because
of its small size (1') and a very straight row of bright stars in it
lined up NE-SW. The line is made up of 4 stars the second one from the
SW end being an easy double. The NE end is Teed by two other reasonably
bright stars. Another row of 3 reasonably bright stars lays alongside
and at an angle to the first row. This is one of my favorite clusters
because of the unusual straight line and it's small size.

NGC 663 lies a degree or so to the E or TR-1. If this one doesn't look
great it's time to bag it. It is at least 15'-20' in size. It is rich
with 4 brighter 9M stars embedded. It is gradually condensed and
contains some nice doubles. A real eye-opener.

NGC 654 is more understated than its neighbor 663 but is still very
nice. It is well framed in a 14' field. It is about 5' in diameter
and well condensed. Pretty rich. It is North and slightly West of
663 by an 8M and 9M pair of stars.

NGC 659 is about the same distance from 663 as 654 but is to the South
and slightly West instead. I can't quite get all three in the same field
in this scope. A 4" Rft should get all five but Tr-1 would probably be on
the edge of detectability. The reason I am blathering on is there is little
to commend this cluster. It is definitely the ugly duckling of the set. It
is about 4' in diameter, is relatively poor in stars, and is not particularly
condensed.

While in the area check out NGC 457. Tom Lorenzin in 1000+ calls this the
ET cluster and I think it is aptly named. Others call it the Owl. To me, it
looks more ET like in an 8" than in larger scopes but it is still recognizable
as such in the bigger ones. Adjectives like Large, Rich, and Glorious come
to mind when looking at it. It is well seen in a 40' field. This is another
of my favorites.

NGC 436 is easily found by going from ETs head through the feet and keep going.
It is a nice sight but is definitely overshadowed by the Alien.

NGC 637 has about 30 stars within an isoceles triangle of brighter stars with
two star forming the tip. Its shape reminds me of a Christmas tree and for some
reason the two stars at the tip reinforces the feeling 8-). It is compressed
around the West most star at the bottom. The size of 3' given in my references
seems to small. I make it 5' unless the stars at the tip aren't counted (quite
possible). The brighter stars in the compressed section make up a crescent.

NGC 609 was sorry looking. It is visible as a very modest sprinkling of stars near
a nice double. It is near 637 so you may as well stop by. It is about 45'-50' NW of
it. It is clusters like this that suffer the most because of the moon.

I now shifted over to the NGC 7790 area. I then worked it S to N.

Be-58 is a pretty poor assemblage of stars about 10' in diameter with about 20 stars
seen. It isn't real well separated from the field but is definitely there.  It is
easy to find since it is pointed to by two 8M stars and is about as far again as the
distance between them.  The stars making it up are fairly faint. SW of this area is
a lovely ice-blue deep orange pair of stars maybe a minute apart. I think the Orange
star is the variable WZ. Isn't it odd that we think of red as hot and blue as cold?

NGC 7790 is a good one. About 50 stars were seen in a well compressed 6'-7' circle.
This is surrounded by a fainter ring of stars about 15' in diameter. The Trumpler
rating is III-2-p. I would rate it an easy II-2-m.  Size is given by some as 17'
so they must count the outer circle. The inner group is elongated E-W. 1000+ describing
the view in an 8" gives it as 25 stars in a 5' compressed group with the brighter
stars to the W.

NGC 7788 lies in the same low power field as 7790. About 20 stars are involved. The
brightest ones make up a kind of rectangular grid. The given size of 3' seems about
right to me. It lies near the middle star in a line of three 9M stars. I like this one
too.

Fr-1 is a small poor group of 5 brighter stars and a few dimmer ones. It is hardly worth
the bother.

H21 is a poor not very compressed gathering perhaps 4' in diameter. It was obvious as
a cluster and contained about a dozen or so stars.

K12 is where we are trying to go. This is clearly better than the last two. It is also
obvious as a cluster; it is better separated and better compressed than H21. It is
fairly rich containing maybe 20 stars. It is not quite up to the standards of 7790 or
7788 but still not bad.  You do have to wonder how the NGC missed some of these.

Well, it was now 6:00 a.m and the Eastern sky was quite bright. There was a small interval
when the moon went down when transparancy was reasonably good. Ah well. The good thing
about the full moon is that it doesn't last. The bad thing is that the time the moon rises
doesn't change much in the fall around full moon.

Clear Skies.