Tuesday, August 27, 2002

Backyard fun 8/27/02

I've had the 14.5" f/5.6 Dob set up in my Los Gatos backyard, uncovered, for the past few nights. I finally went out last night about nine o'clock for a few hours of observing. Well, actually, a friend phoned just as I was walking out to put my eye to the eyepiece. So, it was initially more yacking than observing.

The seeing began decently, although the sky looked rather bright. I will do some star counts in the future to know about what the limiting mag is, but I estimate about mag 3.5 last night. Of course the 10x70 finder helps a great deal under such conditions. In fact, I used the (RA) finder extensively during the night. The eyepieces I used were a 20 Nagler and 12 Nagler, both type II. I thoroughly enjoy these eyepieces... they yield 103x and 172x respectively. The only other equipment used was a Telrad, Volume 2 of the Night Sky Observers Guide (NSOG), older Tirion SA 2000 and older Uranometria 2000.

Cygnus was nicely placed and I began with NGC 6811. This is a nice open cluster just off the "wing-tip" of Cygnus' western arm. Start from mag 2.9 delta Cygni and move past mag 5.1 SAO 48718, past mag 6.25 SAO 48697 and a bit further to an obvious cluster. This is a nice cluster of medium density in an oval or even with some imagination a triangular pattern encircling an area devoid of stars. A nice bright group of about 10 stars sat just at the western edge of my 48 arc-minute field of view. The contrast between the cluster and bright stars so close-by make this a fun visit.

Moving back from Delta Cygni toward Gamma a bit over 4 1/2 degrees I hunted down NGC 6811. It sits just north of an imaginary line between the two bright stars. I also use the stars 32 and 31 Cygni (the later a nice double) to "point" toward the intersection with the line between Delta and Gamma. Worked great! Those of you using The Sky should note that the position appears mismarked. Look at it and you'll find a rather sparse grouping of stars designated at 6811, but look just to the north and you'll find what I believe is really the open cluster. NGC 6811 is a nice open, rich in the center with some haze off to the east side of its densest part, then showing some "wings" extending out to the east and west. There seemed to be more dim haze to the northeast of center as well and possibly another dim arm off to the south.

NGC 6871 was next, lying close to Eta Cygni. I used Gamma to draw a line to Eta, helping establish some scale that I could translate to the Tirion charts. This open cluster sits south-southwest of and very close to the mag 5.4 star 27 Cygni, which appears to be part of the cluster. This is a big, bright and sparse open cluster... appearing to me as a large splash of chains of stars in a line curving in a line north to south. There are about 6 bright members of the group overlaying many dimmer members. I noted what I thought was more of the cluster separated to the east, more bright stars, but dimmer than the members of the western portion. I also found myself marveling at the description of this cluster in the Night Sky Observers Guide! It was amazing in its detail... so precise, what a piece of writing! I can think of only one person that gets such detail.... initials SG. Look at this cluster and read the description. I'm sure you'll be as amazed as I was.

I looked around in the NSOG for other targets in Cygnus. I was quite surprised to find Biurakan 1, another open cluster, listed at 3 stars (relatively easy). Looking at the coordinates I thought they looked familiar... right next to NGC 6871! Heck, it was still in the eyepiece. It was then that I realized Biurakan 1 was the other dimmer cluster of stars east of NGC 6871. The cluster was sparse, just a handful of bright stars with the brightest in the center of the western edge. There were many dim stars in an arc running north to south and arcing slightly back to the east. I also felt there might be another "branch" of the cluster to the west, but it was very dim.

I finished the night looking for NGC 6874. By this time the seeing had deteriorated significantly, and I had to keep adjusting focus and felt I just could not get sharp stars. I could not find this object on the Tirion charts. So I looked at Uranometria. Not there either. What was this about? I spent several minutes checking and rechecking the RA and Dec and going back to the charts, but it really was not there. I then read the NSOG, which called it non-existent. I could not find it. NSOG does claim it is there, and even notes it as more conspicuous than Basel 6. In fact, I thought Basel 6 might have been NGC 6874, and shared locations! But no, I got skunked. However, I did hunt down Dolidze 39 - a hazy open cluster comprised of dim stars north to south about 10 minutes long with a turn on the south end toward the east. A bright seim-circle of four to five stras arced to the north.... this was a very small grouping of stars within Dol 39. Again, it found myself being somewhat confused at what I was looking at... maybe this small knot of stars (the semi-circle) was part of IC 4996. Was it? I now think so.

It was almost 11 p.m. No moon yet, but the seeing was crappy. So, I decided to tear down. Eyepiece in case, books under my arm, I walked the 25 feet to my back door. What a great way to observe!

When I awoke today I found it very windy in Los Gatos. So windy my bino-mount blew over in the afternoon. I now think the bad seeing around 10:30 last night was the very start of the wind picking up, maybe just a shift in direction causing turbulence. It was obvious when it happened. But, I sure had a good time. For the first hour I was looking through the eyepiece while yacking on the phone, not easy to do. The second hour I was well dark adapted and having a wonderful time, enjoying being out in my backyard (t-shirt and sandals, btw!).

Friday, August 16, 2002

Light Pot Cooks The Green Pea ;-)

Friday night at Houge Park the seeing was about as good as I can recall for a few hours after astronomical dark.

The turnout was very good... maybe a couple dozen telescopes and very interested crowds sharing views. I had my 8" CPT(1) (aluminum frame collapsible Dob) riding on a Compact Equatorial Platform(2). The tracking of the platform was flawless, allowing me to center a target and either study it uninterrupted, or allow the public to view without my having to nudge the scope every couple minutes.

The tracking also allowed easy use of higher power. This came in very handy as I went after targets that would otherwise be difficult.

Immediately I found the view of the 1st quarter moon exceptional. I quickly removed the 12 Nagler and went to my 7mm Meade, taking the magnification to 200x. The views down into several of the larger high-walled craters showed intricate detail. Peaks stood out crisply with black shadows in stark relief pointing at the terminator. This was some spectacular seeing. So much so that I soon swapped the 7mm for an Orion 3.8mm Ultrascopic, taking the magnification to 368x, near the theoretical limit of an 8" scope.

What a view! The inner crater walls were showing detail more clearly than I have even seen. I wished, and I know this will come as a shock to those who know my aversion to planetary observing (they are so darned bright!), yes, I wished I could view Jupiter under these conditions.

But alas, I was stuck with awesome views of the Great Light Polluter.

The sky was so washed out due to haze, mag 3 would be generous. So, other than the bright thing, I found myself searching for targets. Aha! Antares was very close to the moon. I swung the Light Pot (hey... its bigger than a saucepan and smaller than a bucket) over, put the 3.8mm back in and... and.... WOW! The Green Pea!(3) Sitting at the edge of Antares glare and the somewhat swimmy diffraction rings was a dull grayish-green dot, in and out, chucking and jiving, but there. I had never seen it in any of my telescope (not that I try often). I called out to a couple other observers next to me. Over they came and one by one looked. The first one asked me as he walked over where to look relative to Antares, and I suggested he look and tell me if he saw it, rather than my biasing him. He looked and nailed the position. Two others looked and also nailed the position.

I called over a very experienced observer and had him look. But the seeing had slightly deteriorated mushing out the little vegetable. Pea soup. Frustrated, the observer claimed a bad-hair day.

I moved the scope up to the Double Double(4), finding it with the 7mm. The conditions again looked superb. Super clean split, even on the tighter pair. In went the 3.8mm. Awesome! The pairs of stars sat still at opposite sides of the field of view. The splits on the pairs was very wide and each of the four tiny stars had beautiful concentric rings surrounding them. If I could only put this seeing in a can and save it! Passers-by looked. They loved the sharp views of this target.

A couple of hours had now passed by and the seeing suddenly trashed. I could get nice splts on the Double Double at lower power... in fact I should not complain... at 200x it still looked good... but I was now jaded by the earlier views. I looked around for other targets.... oh my.... what a poor looking naked-eye sky. I guessed at where M15 should be and got lucky landing right on it. Poo. It was not a very pleasing view. Up to M57. More poo.

Back to doubles. Alberio was drop-dead gorgeous. People came by and would take it slightly out of focus and marvel at how distinct the colors would become when "spread out". Over to Eta Cassiopeia(5). Again, the colors were the show. Very nice!

Then I looked back over at the polluter. Thin clouds had moved in and masked it down so it was less irritating, making it somewhat brown. I looked overhead at Vega and, try as I might, I just could no longer see (at zenith!) Epsilon Lyrae. The sky was going.

I decided to tear down. I talked with friends while putting my equipment away. Looking around I noticed the number of scopes had dwindled to just a handful.

I stowed the equipment in the truck of my car and was home by 11 o'clock.

Nice night. Surprised me as I didn't expect to do much with the scope due to conditions. I'll be back out tonight, trying to put the "DeathStar" into the Light Pot. :-)

  1. CPT - http://www201.pair.com/resource/astro.html/regular/products/cpt/standing.open.left.full.html
  2. Compact Equatorial Platform - http://www.equatorialplatforms.com/compact.htm
  3. Splitting Antares - http://www.carbonar.es/s33/scorpius/Antares.html
  4. Double Double - http://www.in-n-out.com/html/frm_b3.html
  5. Eta Cassiopeia - http://www.carbonar.es/s33/Olimpiada-2002/Casiopea-eta.html