A Little Gem of Woven Fairy Fire
or
How to Have Fun at a Star Party Without a Telescope
I had a great time at the monthly Sacramento Valley Astronomical Society star party at the Henry Grieb Observatory, about 70 miles NE of Sacramento, California on Saturday evening of May 26/27, 2001.
This was the first star party of the season, and it was very well attended, although when I arrived shortly before sunset, I was surprised to see the tarmac only about half full. People continued arriving in a steady stream, however.
At its height, there were three rows of vehicles on the tarmac, and room for a few more. We were not packed optimally, but there was plenty of room for this night. I estimate there were about 50 vehicles, with perhaps 60 scopes and possibly about 80 people.
The largest scope was Gregg Blandin's mammoth 25" that he built himself. Susan Strosahl had her 20" set up. There was an 18", at least 3 16" scopes, and several scopes in the 12" range. And many, many scopes 10" and below. And all were being used to unveil the secrets of the heavens.
As I was setting up my 18" scope, I realized that I forgot my truss poles. I felt it was too late to go back and get them, so I decided to mooch photons off others' scopes for the night and possibly leave early. I asked Gregg if I could help him search for Really Faint Fuzzies (RFFs) with my laptop and his 25", since I had no scope to use. He happily obliged.
Unfortunately, it became rather cool (some might even say "cold") quickly after the sun set, and this definitely cut into the enjoyment of the evening for some. Since I always bring all my cold weather gear when I observe, I was able to apply layers as necessary, having learned from not doing this a few times in the past when the weather was unexpectedly cold.
Luna
The moon was a beautiful object during the evening before setting around midnight. It was a thin, 4 day old crescent, and features on the dark side could easily be seen.
Gregg's mighty 25" was pointed at the moon, so I took a look, and began searching the terminator for rilles and domes, my favorite lunar formations. Rilles are lava tubes which have collapsed and now form small canyons. They are usually sinuous and are reminiscent of water channels. Sometimes, they even seem to flow _under_ craters and hills.
I struck lunar gold when I found Rima Cauchy in the Sea of Tranquility. (Augustin-Louis Cauchy was a 19th century French mathematican, who invented the "calculus of residues" and redefined the derivative rigorously in terms of limits and functions, instead of relying on geometry, rates of change and velocity, as in the past. The name Cauchy was arbitrarily assigned to this feature to honor him.)
It's a very distinctive formation of the crater Cauchy ("Atlas of the Moon" by Antonin Rukl, chart 36), with Rupes Cauchy and Rima Cauchy on either side, in both 25" and 12" scopes. The scarp was casting a thick shadow, and the rille formed a fine and delicate line that required some study to see clearly. The crater was nestled prominently between these two linear features. Neither of these scopes were my own, so I could not spend more time looking, but I am sure that the shadow of the scarp was slowly shortening as we watched.
A little later, I came back to Jim Ster's 12" LX-200, and he was looking at the craters Messier and Messier A in the Sea of Fertility (Rukl 48). We were facinated by the racing-stripe-like double ray emanating westward from A. It was also obvious that the oval-shaped Messier was created by an oblique impact.
M53 and NGC 5053
During the course of the evening, I wandered over to Jane Smith's 12.5", and asked what she was looking at.
"M53 in Boötes," she replied. I took a look in the eyepiece, and there it was, a crisp, bright globular cluster, nicely concentrated in the center. I knew there was another globular cluster nearby, so I began hunting for it, and casually mentioned it.
"Oh yeah, I see it: NGC 5053," she said as she consulted Sky Atlas 2000.0. I continued to search for it, and couldn't find it. We switched places, and I consulted the atlas for its exact location. I also noticed some bright field stars.
She couldn't find it, so she went back to her table and consulted the chart and the Sky Atlas 2000.0 Companion for a description of it.
I went back to the scope and found it. It was really faint, hard to see, sparse, and big. It's a little amazing that two globular clusters so close together could look so different. Ordinarily it would have been much easier to see, but the moon was still up and was casting enough light to make it a bit difficult.
"Here it is, Jane," I said as I stepped away.
She went back to the scope and saw... nothing.
I've had this experience more times than I care to remember. Sometimes, seeing something really faint takes a lot of study in the area. I had done this, and Jane, who had just stepped up to the eyepiece, had not yet, so it was not surprising to me that she saw nothing.
She scanned around a bit, thought she had found it, and asked me to look. It wasn't there. I went back to M53, and just barely fit it into the same field with M53 with the 19mm Panoptic eyepiece she was using. In the eyepiece, NGC 5053 was just to the left of a relatively bright star.
Maddened by not seeing it, she went back to the description and quoted a banal description that matched what I saw. "Yeah, that's right. It's really hard to see."
Then she casually remarked, "It's a little gem of woven fairy fire."
"WHAT??!"
"It says that right here!" she said, laughing.
I looked and saw that the Sky Atlas 2000.0 Companion was quoting Walter Scott Houston. In fact, those very words appear on page 136 of "Deep Sky Wonders" by Walter Scott Houston, adapted from his monthly columns in Sky & Telescope by Stephen James O'Meara. This is an excellent book which really captures and magic and wonder of observing with well-written prose.
After that, I repeated that sonorous phrase over and over whenever anyone asked me what I was observing. Sometimes I said it without any prompting at all.
Mars
Around midnight or so I looked at Mars in the same 12.5" scope, and it first appeared as a featureless orange circle, but after some study, and waiting for good moments, it became evident that there was a large dark area in the southern hemisphere. At the time, I thought this was Syrtis Major, but it is clear after calculating a Central Meridian value of 73 degrees (Sky & Telescope, May 2001, pg. 106), that we were seeing Margaritifer Terra and with the light colored Chryse Planitia just below it. (Viking I and Mars Pathfinder and the "face" are all in this general area. The Soviet Mars 6 probe crashed in Margaritifer in 1974.)
Light areas were visible on both sides of the planet, with the southern one being much larger. This was a combination of the South Polar Cap and Arguire Planitia, and the northern one was the North Polar Cap, although I never saw the cap as the usual small with point. It was just a general lightness in the area.
I also looked at Mars through Jim's 12" LX-200.
Treasures of the Milky Way
Finally the moon set, and the Milky Way transformed from a washed-out, low-contrast object to a detailed, spreckly celestial river flowing out of the north east, through Cygnus, Aquila, Scutum and Sagittarius.
In Gregg's 25" with a borrowed O-III filter, we got fabulous views of the Veil supernova remnant with its lacy tendrils reaching around in a magnificent circle, the Dumbbell Nebula, the Eagle Nebula with its embedded star cluster, the Swan Nebula, The Trifid Nebula and the Lagoon Nebula with its embedded cluster. Each was different, each was unique. Each offered breath-taking detail and beauty.
Gregg still had a crowd around his scope happily showing these fabulous sights to people who were there for the first time, so I sat down to rest my weary feet. It was wonderful to talk with my friends as the stars wheeled overhead, and we could hear Gregg eagerly explaining the wonderful sights people were seeing in his 25".
I didn't want to leave and I didn't want this night to end.
Cruising the Blandin Deep Field
Finally, at about 3am, the crowds evaporated and Gregg and I could begin our work. We lamented the late hour of starting on the hard stuff, but we went ahead.
We decided to anchor our search on a bright galaxy, and then find dimmer ones nearby.
At my suggestion, we came up with the brilliant idea of using M101 as an anchor. This idea was actually not too brilliant, because we immediately began confusing emission nebulae in M101 for faint galaxies. I also had some difficulty matching the scale of what was being seen in the eyepiece with what was displayed on the laptop chart.
M101 itself was absolutely magnificent, with lots of spiral arms, and bright knots scattered throughout them.
All quoted magnitudes are B magnitudes.
Eventually, we found our space legs, and I located MCG+9-23-25, a mag 15 galaxy about 17' WNW of the center of M101. It looked like a little gem of woven fairy fire. This one was not too challenging.
We also noted mag 14 NGC 5477, 21' E of the center of M101. We then hit mag 10.8 NGC 5474. Whoops. We were getting brighter.
We took stock of what we were doing and the "success" we were having. We decided to use a different anchor galaxy, so Gregg, looking at his Herald-Bobroff, decided to pick NGC 5368, about 1 degree W of M101.
He quickly found the mag 13 galaxy, and we began looking for other faint galaxies in the same field, or nearby.
LEDA 99755 (Lyon-Meudon Extragalactic Database), mag 16.9, was located on the other side of an equilateral shaped asterism about 11' SW of NGC 5368. No fairy fire here: This one was barely visible.
I believe I also saw LEDA 99757, mag 17.1, located 15' S of NGC 5368.
At this point, it was about 4:15am and Gregg and I were getting pretty tired, and we were getting frustrated with our Deep Field search, so we turned the scope on the very bright and close Saturn Nebula, NGC 7009.
We could easily see the ansae, and the somewhat oval planetary nebula was very, very deeply blue-green colored. It also had a somewhat mottled appearance.
With this, I was done. It was getting light in the east, and Gregg made a last mad search for his favorite open cluster, NGC 7789 in Cassiopeia.
It had been a great star party, and I learned how to have fun at a star party without a telescope.
Technical Data Date: May 26/27, 2001 8:30pm-4:30am (May 27 3:30-11:30 UT) Location: Henry Grieb Observatory near Sacramento, CA - 36.85N 121.57W Instrument: Various Seeing: 8/10 Transparency: 8/10