(SNES) What a Night! (long)

[Albireo54@aol.com]

Hi all,

The old line "all things come to those who wait" was certainly in evidence 
last night. As Les found out early this morning, conditions were spectacular! 
It seemed that all the air that had been backed up behind that nasty weather 
front had just stopped moving altogether - providing us with the most stable 
seeing in memory. In fact, I can't EVER recall seeing steadier air! 

I spent 3 full hours enjoying one fine sight after another, and won't go into 
all the details, but here are some of the highlights.

Comet Linear - easily seen in my C8, but no longer visible in my 10 x 50 
binoculars. I would estimate its magnitude around 9 - just a hazy patch of 
light. It is rather easily found, as the arrow of the constellation Sagitta 
is now pointing directly at it, and will for the next few nights. Once 23 
million miles from Earth, it is now just over 70 million.

Uranus and Neptune - both planets showed amazingly sharp, crisp disks at high 
power (303X). I could see Neptune's moon Triton, barely, but none of Uranus's 
moons. I've never seen these in my C8, but may bring the scope down to FDO 
one dark night to try there. 

M71 (Sagitta) - this odd globular always looks more like an extremely rich 
open cluster in my C8, although FDO's 16" shows that it is quite clearly a 
globular. Large, diffuse, and oval shaped in the 8", lying in an extremely 
rich star field.

H20 (Harvard 20, Sagitta) This cluster, just 27' SSW of M71, looks quite 
impressive in photographs. But because of the very rich Milky Way background, 
it's difficult visually to separate the cluster stars from the background 
stars. A smaller aperture may actually do a better job of this.

M27 - the Dumbbell Nebula. Spectacular as usual! I'm always impressed by the 
sheer size of this object, let alone the fine detail that shows up on a good 
night. My Orion Narrow Band filter (which I often just hold in place over the 
eyepiece for a quick look) brings out even more faint structure.

16 Vulpecula - what a victory this was! This star, just a couple of degrees 
NNE of M27, is a close double that I'd never successfully split in any 
telescope. The components are both pale yellow, have magnitudes of 5.8 and 
6.2, and are separated by just 0.8". This is not much above Dawes' limit of 
0.57" for an 8" scope. At 303X I could see that there were definitely 2 stars 
involved, with the fainter one lying (in my inverted field) just to the right 
and slightly below the primary (to the ESE). I switched to my 18mm 
Orthoscopic mated to my 3X barlow for 340X, and I could see space between the 
stars - the images were rock steady, with sharp, concentric diffraction 
rings. But the fainter star was lying right on one of these rings, so I "went 
crazy" and put my 6.7mm Meade Ultrawide into my 3X barlow for 911X. Wow! 
Although each little breath of air movement would smear the image, it would 
then settle down to two rather steady and sharp images. I estimated the 
position angle of the secondary at about 110 degrees from the primary - and 
confirmed this later in my Sky Catalogue 2000, which lists it as 115 degrees. 

To think that I was worried about my scope's collimation! Hah! And so much 
for the concerns about an SCT's resolving abilities. It all comes down to 
atmosphere! I seriously doubt that we will ever be able to split this double 
in FDO's 16" (despite it's theoretical limit being 1/2 of the 8") since we 
are normally hindered by air currents rising out through the dome opening. 
But Steve, here's a good star test to schedule for that new 12" LX200 when 
you get it up and running on a good night in FDO's yard. If I can split this 
baby in my C8, you should be able to do it with ease in a 12"!

The sky, although rock steady, was not the darkest I've had at Webster (still 
some residual moisture in the air), but I set out to find some rather faint 
objects anyway. One I'd often wondered about was the "bright" nebula NGC 
6820, 4 degrees W of M27. Within it lies the cluster NGC 6823. With my wide 
field 32mm Konig (64X) I was able to see the nebulosity dimly, but would have 
passed right over it if I hadn't been looking for it. The cluster is 
interesting - loose, a few bright stars, and a fine quadruple star at its 
center forming a flattened diamond pattern. The nebula will certainly be 
worth a look down at FDO, as it has several very dark intrusions in it which 
can supposedly be seen visually.

NGC 6802 - this small and dim star cluster lies just at the eastern tip of 
the famous Brocchi's Cluster (The Coathanger, CR 399). It is quite rich, with 
at least 50 members, but its brightest stars are listed at mag 12.9. In my C8 
I could glimpse perhaps 6 or 8 stars, with all the others forming a dim hazy 
background. The cluster has a distinct oval shape, running N/S. Visually it 
very closely matches the Palomar DSS photo, seen from 6 or 8 feet away. 
Another good target for FDO's big scope!

NGC 6905 - planetary nebula in Delphinus. This is the "Blue Flash" planetary. 
Listed as only mag. 12.0, it was not a difficult object in my C8. It is 
nearly circular in shape, a bit flattened, and is brighter and more sharply 
defined on its eastern edge. I did not see the mag 14.0 central star, nor did 
I see the two faint ansae that extend from either side, giving the nebula 
it's "flash" name. Both the central star and the ansae were seen a month or 
so ago in the 16" at FDO, which also brought out the planetary's blue color. 
The nebula sits in an interesting field of four fairly bright stars.

52 Cygni and the Veil Nebula. The Veil Nebula is always exceedingly difficult 
for me to spot under my Webster skies - you really need a darker background. 
But last night I succeeded in viewing the brightest portion, north and south 
of the orange star 52 Cygni. This was with no filtering at all. I sure wish I 
had an Oxygen III filter to use on this object! But the filamentary structure 
was at least dimly visible. 52 Cygni itself is a fine double star, with nice 
color contrast. The stars are mag. 4.2 and 9.4, separated by 6" - so they are 
a challenge in small scopes, due to the magnitude difference. The colors are 
orange and blue/green, although the color of the fainter star is difficult to 
detect - it may be just my imagination!

NGC 6940. This very bright and very large cluster (as big as the full moon), 
lies just over the Cygnus border into Vulpecula. It sports at least 100 stars 
magnitude 9 and fainter, and has a definite "bar" of stars running 
approximately E-W. A fine sight in any scope.

NGC 6894 - Planetary in Cygnus. This was a challenge and a half! The Deep Sky 
Field Guide to Uranometria lists this PNe at nag, 12.3 visual, and 14.4 
photographic. So, adventurer that I am, I spent quite a long while trying to 
locate this guy. Supposedly it is about 40" across and is a disk within a 
ring. Well, no luck, despite taking the time to positively identify the star 
field within which it sits. I guess I'll have to try this one in the 16" as 
well! (Hey Dave A - have you seen this one? Also known as PK69 2.1.)

I spent some time visiting old friends like M15 and M2, and the wonderfully 
rich cluster NGC 7789 in Cassiopeia, and then decided to close out the night 
with a search for a galaxy and cluster pair in Cepheus that I'd been studying 
indoors on our many cloudy nights. They are NGC 6939 and 6946, which lie just 
38' apart, just SW of Eta Cep. They are a magnificent sight in photos - a 
rich star cluster and a fine face on spiral galaxy. The galaxy is quite 
bright (mag. 8.8) but is large, 14' across. So its surface brightness is 
quite low, around 14. In my C8 it was not too difficult to see, but was just 
a hazy glow, with slight brightening toward the center. The star cluster, 
about 8th magnitude and 8 minutes across, appears to be quite rich, but its 
brightest stars are only slightly above 12th magnitude, so a larger aperture 
will help, once again. FDO - here I come!

By 1 AM my mind was beginning to fog over as fast as my telescope - a pretty 
decent dew was on the way. So rather than cranking up the dew zapper and 
waging a war with the dampness, I decided to call it a night. And a wonderful 
time it was! How long I wondered, as I trundled off to bed, before I'll see 
another such night?

Hoping a number of others were able to get out and enjoy themselves!

:o)
Doug Stewart
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