by Randy Muller
It had been about a month since I was out last, so it felt good to get out to a dark site and observe the wonders of the night sky on Saturday night, July 6th, 2002. I went to my usual summer hangout (the Henry Grieb Observatory, dark site for the Sacramento Valley Astronomical Society) off I-80 about 50 miles from my home in Roseville.
Alvin Huey brought his 22" dob, along with his wife's cousin and his old 16". Allan Keller had his increasingly customized 17.5" Astrosystems Telekit. He said he was planning on creating framed trusses, similar to my Starmaster, for better rigidity. Jeff Lawton had an 8" LX200 with a Televue 85 mounted on it, and was doing film photography. Bill Chandler was also there, but I didn't see his scope.
Frank Dann and some other SVAS members I didn't know were also there. Cary Chleborad showed up to talk to Allan, but left before dark. He reported that he was working on some software, which I presume was for something in the observatory.
It was a nice night, but we were plagued by clouds and poor transparency when there were no clouds. The seeing, however, was superb.
Around June 26, 2002, there had been a couple of long threads on collimation in the Starmaster mailing list
http://groups.yahoo.com/group/starmaster_scopes/
Rick Singmaster, the maker of my 18" scope, chimed in on what he thought the procedure should be. It was somewhat different from what I normally do, and because I hate blindly relying on authority for its own sake, I continued doing what I learned to do on my own.
When I first got my 10" Discovery-made Orion dob in 1996, I also got the Tectron collimation tools, and spent quite a bit of time learning how to collimate my 10". This was time well-spent, because the views through the 10" improved vastly. I started out only being able to see 4 stars in the Trapezium in the Great Nebula in Orion, being unable to split the Double Double, viewing Mars as a ball of orange fuzz and seeing only 2 bands on Jupiter. I finished being able to split the multiple stars and seeing a wealth of detail in Mars, Jupiter and Saturn.
When I got my 18", I started using the laser exclusively, because it was so much easier. It was close, but not dead-on. I didn't worry too much about it, but as time has gone on, the issue has been gnawing at me.
Since the recent collimation thread on starmaster scopes, I decided to try it Rick's way. I used the laser to adjust the secondary, and the autocollimator to adjust the primary, which was different than what the laser required. The results were amazing. I could tell at once that my scope was better collimated when I viewed star images. It helped that the seeing was one of the best nights I've ever seen.
I began the evening before it was fully dark by cruising through Markarian's Chain (of galaxies) in the heart of the Virgo Cluster. I was a little surprised at how high it was in the west, so I decided to take the opportunity to say goodbye until next year.
I always find this by pointing the scope about halfway between the tail of Leo (Denebola) and the first reasonably bright star in Virgo (Vindemiatrix; epsilon Virginis). Such a line neatly skewers both elliptical galaxies M84 and M86. Since they are a hair closer to Vindemiatrix, if M84 and M86 are not in the field of view, I nudge the scope towards Virgo, and eventually they come into view.
I enjoy the "doubleness" of this galaxy chain, starting with the the mighty giant ellipticals, M84 and M86. Next come pair NGC 4435 and 4438. Then the pair NGC 4461 and 4458. Next comes a singleton, NGC 4473, and then a final pair, NGC 4477 and 4479, although NGC 4479 is not listed in Markarian's original paper.
I first observed this chain by accident from my light polluted backyard with my 10" dob in 1998:
Ever since observing this chain, and hearing it referred to as "Markarian's Chain", I've often wondered how the name came about.
A search of NED (http://nedwww.ipac.caltech.edu/index.html) reveals that B. Markarian published a paper in Astronomical Journal (1961 vol. 66 p. 555-557) with the title, "Physical chain of galaxies in the Virgo Cluster and its dynamic instability".
In the paper, he presents a statistical argument that the chain of galaxies (M84, M86, NGC 4435, 4438, 4458, 4461, 4473, 4477) is not a chance arrangement, but actually represents a physical chain, and that it is dispersing.
The name "Markarian's Chain" undoubtedly derives from this paper.
After finishing with Markarian's Chain, and noticing that the seeing was excellent, I decided to look for the jet in M87. At 301x, I could not see anything that looked like a jet.
Soon, clouds covered the area.
Just cruising around Virgo told me that the transparency was low.
My primary program is hunting down Abell galaxy clusters, but I could tell immediately that this was not to be a night for Abells, with the poor transparency, because most of the galaxies in these clusters are relatively faint. My backup program consists of faint galaxy triplets, and it was therefore not a good night for those, either!
I decided to hunt down some galaxies in Ursa Major, so I started with one of my favorites.
The spiral structure in the galaxy M109 was barely apparent. This galaxy is enormous (compared to the galaxies I normally look at) and has a very bright central region. It has a huge diffuse oval halo.
M108, a tortured irregular-looking galaxy that is actually classifed as a barred spiral, looked pretty good. Nearby M97, the Owl Nebula, also looked good, with the owlish eyes visible, staring back at me across interstellar space.
Soon, clouds covered the area.
Beginning to feel a little frustrated, and disarmed by the sky conditions, I decided to give up on galaxies for a while and go after bright stuff that would respond well to good seeing. Also, I had to switch to a cloud-free section of the sky.
I swung over to the Ring Nebula, M57, in Lyra. At 301x and under the excellent seeing, the central star was visible intermittently. This is only the second time I have observed it. It was only much later that I observed the irony that "nebula" is a Latin word meaning "cloud".
I decided to observe more bright nebulae (and some clusters) in Sagittarius. I quickly ran through the "standard" bright nebulae
Based on Marsha Robinson's interesting observing report
I chased down the dark nebula Barnard 86 (the Inkspot Nebula) and its nearby companion open cluster, NGC 6520. I first saw this at Lassen in 1999 in Bruce Jensen's 18". What a beautiful juxtaposition of negatives. Normally, most nebulae I view are bright emission nebulae against a dark, mostly star-less background. This was a B86 is an irregularly shaped and utterly black mass superimposed on a rich and bright field of stars. The kicker is seeing NGC 6520 right next to it, with its bright and lovely and colorful red, yellow and white stars.
Nearby in this interesting area packed with jewels lay the fainter globular cluster NGC 6540. With a separation of 41.3 arcminutes, I couldn't get all 3 objects in the same field of view with my plossl eyepiece, but I imagine anyone with a wide field ep can do it easily.
Also in the general vicinity I stumbled upon two globular clusters, NGC 6522 and 6528 only a little less than 17 arcminutes apart. These I did get in the same field of view.
Soon, clouds covered the area.
So I switched to the north and viewed M52, a nice bright open cluster in Cassiopeia. I remember searching for this when I was a young lad in the late 60's with a cheap 60mm refractor and the star-poor charts in "Amateur Astronomy" by Patrick Moore. I failed to find it then.
Poking around aimlessly, I stumbled upon a bright comet-shaped nebula with two stars in it, very similar to the view of M78 in a 10". The object was not on my chart. After I got home, I downloaded the latest orbital elements for comets, and pulled up the field of view in Sky Map. Still nothing. I had written down the coordinates after I observed it, so I used SIMBAD
to search for objects by coordinates. I was very surprised to see that it was NGC 7538. I went back to Sky Map and it showed up when I showed all objects, instead of limiting them by magnitude.
After viewing the bright globular clusters M3 and M5, I happened to notice that Palomar 5 (another globular cluster) was only about 2 degrees SSW of M5. I pointed the scope there and found the field and saw ... nothing.
"Uh oh, this might be one of the difficult ones," I thought to myself as I increased power to 226x. I could just intermittently detect a fuzzy something, small and star-like about 1 arcminute E of the mag 14 star GSC 5002-0587. I don't know whether I was seeing the unresolved core of the globular or actually resolving some stars in it. Whatever I was seeing, it wasn't much in the conditions.
About 1am, very low in the NNW, a bright green bolide appeared, trailing yellow sparks and traveling down at a very steep angle. It was still going strong as it went below the horizon (which is very close to zero degrees in that direction).
"Whoa!" I shouted.
There was a responsive clamor from some of the other observers. It's funny, but whenever I see a bright meteor, I usually and involuntarily utter some kind of vocalization.
I happened to be sitting at my north-facing table making some notes and I saw it start its run out of the corner of my eye, so I looked up and saw nearly the whole thing.
While Allan and I were excitedly talking about how bright and colorful it was, another one traveled in the exactly the same path a few seconds later. The second one was not nearly as bright or colorful, but it still did have the same green color.
We got excited all over again and discussed how many of these double meteors we saw at the Leonid meteor storm in the early morning of November 18, 2001.
An observer near Weed, CA, reported the same bolide and thought it was very close, and that it hit the ground nearby. They spent a little time searching for it.
All in all, it turned out to be an eventful and enjoyable evening despite my plans for doing something different!!
| Date | July 6, 2002 8:30pm - 2am (July 7 3:30 - 9:00 UTC) |
|---|---|
| Location | Henry Grieb Observatory near Sacramento, CA 36.85N 121.57W 5284 ft |
| Instrument | Starmaster 18" f/4.3 dob-newt |
| Oculars | Sirius plossls: 26mm, 17mm, 10mm, 7.5mm 1.15x Paracorr |
| Seeing | 9/10 |
| Transparency | 6-7/10 partly cloudy |