Friday, June 2, 2000

Celestial Prospecting and Dreams of the Dragon's Dwarf.

Several observers met at the Fiddletown Observatory, in the foothills of the Sierra Nevada, among the historic placer gold mine country that gave California its free spirit and entrepreneurial nature. For two nights on June 2nd and 3rd, the star party grew from five observers to sixteen. The setting made me think of miners, Long-Toms in the streams, looking for glittering treasure so long ago. In fact, along the back road we take to the observatory, evidence of those activities some 150 years ago are still evident.

Our group was there to hunt for treasure too. But, ours was overhead rather than underfoot. And, ours was the stuff that gold was made of. Supernovae, galaxies abundant with interstellar streams of heavy elements seeding untold planets with the stuff that made the dreams of the Forty Niners.

I would be in Virgo, Bootes and Draco. These man-made celestial boundaries contain sights I have found elusive. The quantity is immense, and I do not expect to deplete the areas soon. It is also difficult to find, for the same reason the Forty Niners were essentially seasonal workers. The winter rains swelled the stream beds making it nearly impossible for the miners to work, as did muddy trails and cold temperatures. These are all problems faced over the several years of El Nino and La Nina by Calfiornia observers, wanting to explore the realm of the galaxies. You take your treasure when you can, and the effort can be frustrating, but the reward is what kept the 49ers, and keeps, the observer, searching.

Ken and I talked on radios for the drive from the SF bay area, all the way to Plymouth and to the observatory. Arriving, we found Ray Cash, set up for CCD. After greetings and a cold drink, Rashad Al-Mansour pulled in. Later, Steve Gottlieb showed, then Jeff Blanchard, both having fought through the rush to the hills typical of Friday afternoons in and around California's major population centers. This was much the same as the difficulty prospectors faced, when all humanity rushed away from San Francisco, in a mad dash to the hills.

As darkness overtook day, Arcturus appeared. Its golden glow shone dazzlingly in the eyepiece of my 18" Dob. During the night I would use a 20mm Nagler Type II predominantly, and a 12mm Nagler type II for higher mag views. Anticipation grew as the magic time between sunset and the first target slipped by. When dark was on us, we knew what we'd drive three hours for. Coe, The Peak, Pacheco... sorry. The sky was aglow with stars that never come out near home. It is a treasure one must seek out, lost to most, but not difficult to find.

For brevity, I'll cover a few of my favorite finds, and list the others by catalog number at the end of the writing.

A few moments stood out from the first night. One was area around NGC 4235. This galaxy appeared along with several others in the same eyepiece field. Not a surprise in Virgo, but these were large, bright galaxies, quite different from the usual quarry I find on the Herschel list.

N4235 was elongated, perhaps 5'x0.8', seemed to be similar to famous NGC 4565. It contained an obvious stellar core with a hint of a dust lane along the major axis of its ESE section. The galaxy sat ESE/SSW shining at mag mag 11.6, surface brightness (sb) 13, with a mag 8.4 star 14' to its WWNW. Galaxy NGC 4224 saw 20' WNW of 4235. 4224 is another elongated galaxy, laying SW/NE at mag 11.8 (sb 12.7). 4224 seemed to exhibit some hints of spiral stucture. The galaxy was about 3'x1' with the mag 8.4 star about 7' to the S. Back at 4235, a dim triangle of stars lay 13' E. From the triangle, NGC 4246 was 12' to the N, and NGC4247 5' still beyond to the N. 4246 appeared an elonated mag 12.7 (sb 13.8) glow, with 4247 smaller, dimmer, and roundish at mag 13.5 sb 13.3. Again at NGC 4235, travel 25' N and find NGC 4233, a bright galaxy at mag 11.9 (sb 12.8), I logged as having a stellar core, possibly round with an E/W slight elongation. After checking radial velocities at the NED site on-line, this group proved to in fact be a group, all traveling away at roughly the same speed.

Other gorups were eye catching that night, and are listed below.

Probably the find of the night was an accident. A point arose when the spring galaxies were setting and I needed something to do. I pulled out my seldom used summer volume of The Night Sky Observers Guide and decided to see what was in Cygnus. The fell open on planetary nebula PK85-4.1, also known as Abell 71. I'd never heard of this object, but was somewhat familiar with the name Abell, and had considered it a potential project during the time of year when I was out of Herschels. So, what the heck, Abell 71 it would be. After a bit of hunting around, I happened on a dim spot, perhaps round, perhaps a bit lumpy on the edges. It was not overly large, about 13'x 13'. But none of this matched the description. I was on Sh2-112. I worked over the area for what must have been an hour, beginning a star hop from Deneb, using my 11x70 finder, no dice. I hit Sh2-112 over and over (I didn't know what it was until the next day). I finally called Steve Gottlieb over. He agreed Sh2-112 was far too bright to be the object we were after. Finally, through rotation of the field on the computer, we had star patterns that matched. A chain of five 7th, 8th and 9th magnitude stars led directly to a ghostly, extremely dim round haze, barely perceptable on occasion. Both Steve and I felt something was there, but the next day after Steve read his notes (and discovering the i.d. of Sh2-112), it was learned that the object was on Barbara Wilson's "ain't no" list from the Ultimate Star Party. Steve then reclassified the sighting as "probable." I think that's fair. Still, as was pointed out, there is a description both in Uranometria and The Night Sky Observer's Guide, so somebody must have seen it! Perhaps I did too!

The next day found Ken cooking a breakfast that the old gold miners would have paid a day's dust for. Eggs, sausage, potatoes and salsa cooked up and rolled into breakfast burritos. Fresh melon, coffee, orange juice. You really don't need to rough it when roughing it! Of course, there are certain ammenities missing (the outhouse literally seems to be circa the Gold Rush, and the only other option includes the red-handled camp shovel), but with the great food, soft futon on which to sleep, and heavenly entertainment all night, these were really pretty good digs!

By nightfall on Saturday the place was packed with celestial prospectors. Sixteen in all. I am not a real regular at Fiddletown, having been maybe once or twice more than my trips to Michelle Stone's Plettstone sky preserve, but this turnout was unprecidented in my experience other than near town star parties. And I know, others wanted to come! Looks like amateur astronomy in the bay area is developing some real die-hards who want skies that are worth looking at. And that's what we had Saturday night.

When Bootes was up high, Jeff Blanchard and I did the star count. Jeff came up with 39, giving an amazing mag 6.8. In four counts I came up with 46,47, 48 and 49. 45 stars is mag 6.9. 52 would be mag 7.0. Not a bad sky. Note: For those who recall my stating the count numbers are suspect, I had looked at the list for Leo mistaking it for Bootes, in which case 45 stars would have been off the chart over mag 7.5, oops!

The highlights on Saturday were two fields, one in Bootes, the other in Draco.

NGC 5463 led me into a chain of galaxies that are in some respects similar to famous Markarian's Chain (but of course, Markarian's is much brighter, and there is only one such truely amazing chain!). 5463 is a reather non-descript galaxy, shining at mag 13 with a sb of 12.2. Wait... a surface brightness brighter than the magnitude? Strange? We'll see. The galaxy has a size of 1.1'x 0.5'. But this was not the interesting part. About 50' west were a pair of stars, mag 6.2 SAO 120251 and mag 6.9 SAO 120232. Between these two stars begins a chain of galaxies, rich as a vein of gold between bright quartz.

The first pair between the stars was NGC 5409 and NGC 5416. These were relatively bright at mag 13.3 (sb 13.8) and 13.3 (sb 13.3). 5409 lay NW/SE but somewhat roundish, maybe 1.7'x1.0'. 5416 lies about 8' E of 5409, and is almost the same size, but in a W/E orientation. About 11' E of 5416 are a pair of galaxies, really a triplet. The pair are NGC 5424 and NGC 5423. Perhaps 2' E of that pair sits NGC5431. These galaxies are, respetively, mag 13.1 (sb 13.7), 12.8 (13.1) and 13.8 (12.7) ... hey, there's another galaxy with a higher sb than magnitude! What's going on here? These three galaxies range in size from 1.6'x1.3' down to 0.8x0.6, and form a nice equallateral triangle with about 2' to 3' between each component. Not exactly M84 and M86 or The Eyes in Markarian's Chain, are they? Still, this chain in Draco continues and is very enjoyable to trace out. Next, from NGC 5431 we head NE about 5' and find NGC5434, a face-on spiral appearing round at 1.8'x.1.8'... and shimmering there at mag 13.2 with sb of 14.4. Not even 1' NE of 5434 is UGC8967, a thin slash of light measuring 1.8'x0.4', at mag 14.67 (type Sbc). 6' W of UGC8967 is NGC 5437, a roundish galaxy at 0.8'x0.4'... mag 14.1 and sb 13.1! The chain finishes up with NGC 5436 6' N of 5437, and NGC 5438 just 2' NE of 5436. These two galaxies are 1.1'x0.4' and mag 13.9 (type S0/a) and 0.3x0.3 at mag 13.7. Ten galaxies in a chain fitting within a 48' field of view! What an unexpected treat... nice little nuggets found by combing a little off the beaten path through the gold fields of the Hershels.

The last of the wonderful sights I will write about was a nice chain of four galaxies centered on NGC 6338. Four galaxies are lined up almost due N/S all within 6' of each other. They are (north to south) MCG10-24-117 at mag 14.6 and 0.25'x0.15' (this is a *tiny* little thing, but it has a high surface brightness!), NGC6338 at 1.5'x1.0' and mag 12.3 (sb 12.7, type cD;S0), NGC 6345 at 0.6'x 0.4' and mag 14.4 (type S/S0), and NGC6346 at 0.2'x0.2' mag 14.6 with a sb of 11! Look at that difference... mag 14.6 and sb of 11! Too strange! For the record, there is one other little galaxy in this group, IC1252, 5' E of NGC 6345. The IC is 1.0'x0.2', type Sa-b and mag 14.7.

Fun little chain. But what made it even more special was on the computer screen. Just nudging into view was a giant. Or was it a dwarf? It was approaching dawn on Sunday morning, and I was beginning to stumble. Travelling toward us at 281 kilometer per second, this seemingly gigantic object is 35.5'x24.5' in angular size and shine at mag 10.9. It is elipitcal and peculiar. I began star hoping from the little chain of galaxies off NGC 6338. The Draco Dwarf. Jim Bartolini and I viewed it from Fiddletown last year. I couldn't find it. Was I dreaming the dwarf was there? Again, back to the chain of galaxies. Star patterns running NNW/SSE that forms a shovel, from there over to a chain of stars that curves right into the heart of the dwarf. Nothing there. This dwarf is a conundrum, apparently big, but really small. Seemingly bright, but exceedlingly dim. His magnitude is deceiving since the light is so spread out. Does anyone know what the surface brightness of this object is?

I asked Steve Gottlieb to come and look. The star field was right. Nothing showing. Finally, I hopped stars foreground to the Dwarf, and exited the NE edge. There was a contrast difference. Running roghly between GSC 3900:1294 and GSC 3900:786 I could see an edge. Or was I dreaming? I was tired and it was hard to tell. Another probable, but a good chance I saw it.

Weary from two nights of sky mining, I put in the OIII and pointed at The Veil. What magnificence! Streaming tendrils of the future ripping through the dark emptiness between the stars of our little part of this galaxy. New life for the little corners of our Cosmos, heavy elements, the hand of creation, the golden touch. The view was one of the best I've had. I called David Kingsley, one of the last standing observers, having him take a peek.. Wispy, woven, pieces so intricate and dense that it could have been knots in the Swan Nebula. Glowing sections looking nearly neon just off 52 Cygni. It was the perfect way to end the night.

The sky was brightening and the stars were disappearing one by one. I thought of the Nine Billion Names of God. I inhaled the sweet smells of morning and headed for my truck and bed.

My saddlebags were full of golden memories as I closed my eyes for sleep.

Other objects observed (groups are listed together):

Virgo 4124
4239 / 4333 / 4326 / 4376 / IC3262 / MCG1-32-56 / IC782
4378 / MCG1-32-42 / 4324 / UGC7516 / 4303 / 4303A
4417 / 4424 / 4442 / 4380 / 4445 / 4451
Bootes 5417
5482 / UGC9015 / MCG2-36-45
Draco 6143

Steve Gottlieb explained about situations where surface brightness exceeds magnitude. A prime example was sited about with NGC6346 at 0.2'x0.2' mag 14.6 with a sb of 11. That's a huge difference. One normally expects surface brightness to be equal to or dimmer than magnitude. But in the case of NGC6346, the size of the galaxy is less than 1.0'x1.0'. Surface brightness is the average magnitude per square minute of the object. With an area under a square minute, the sb computation shows brighter than the magnitude. Interesesting? I'm sure other could explain this in greater detail than I. Just one more bit of information that helps me understand what I see.

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