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Observing report: All-Arizona Star Party 2010

November 7, 2010

A few months ago I found a good deal on a used 12″ reflector. The guy selling the scope, Darrell Spencer, lives in Phoenix, and offered to drive part of the way for the handoff. We met at a diner on I-10 in Arizona and had a great conversation over breakfast. In particular, we talked about our favorite dark spots and the chances of meeting up to observe sometime. We parted fast friends, and both started scheming about how to meet up under dark skies.

With the new moon, pleasant temperatures, and clear skies over most of the southwest, this weekend was a big one for star parties. Through various clubs and friends I heard of at least four here in SoCal, and I’m sure I would have had a great time at any of them. But the one I ended up attending, thanks to an invite from Darrell, was the All-Arizona Star Party, out in the desert about 50 miles east of the California border. Darrell didn’t know I was going to take this picture until about half a second before I clicked the shutter, hence the expression.

The AASP was going on both Friday and Saturday nights, but I could only afford to do one night, and the forecasts called for Friday night to be a little bit better. I picked up London after kindergarten and we hit the road.

Launch

We rolled in about half an hour before sunset, and found a spot next to Darrell. Steve Coe and AJ Crayon were set up on either side, so I was hanging out with some truly legendary observers. They also turned out to be darned nice guys. Here’s AJ’s truss dob cooling down on the right, with my XT10 on the right.

There had been a few wisps of cloud in the sky when we pulled in, but as the sun set they evaporated, and by the time the first stars came out, the sky was clear except for a little fuzz over the Phoenix light dome, low on the eastern horizon. The last of the sunlight striped the western sky with some beautiful crepuscular rays.

I spent the couple of hours just surfing around the sky, hitting some seasonal favorites. London looked at a few things but spent most of his time watching for satellites and shooting stars. At 7:20 most people on the observing field stepped away from their scopes to watch the western horizon. There was supposed to be a rocket launch from Vandenberg, a Delta II putting up an Earth-observation satellite (here’s the story from the Vandenberg site). At 7:21 we saw a bright spark flying low over the western horizon. That’s what 100,000 lbs of thrust looks like from 300 miles away. It was the first time I’d ever seen a real rocket in flight. London was even more thrilled, if that’s possible. He also spotted a couple of satellites and shooting stars, so he got everything on his list. I had a list of my own to deal with.

Into the Deeps

London was dead asleep by 8:00 and I settled in for a nice long observing run. I was tracking down the last few objects I needed for the AL Caldwell Club, and starting on my next big observing project, the Herschel 400. A few of my favorite objects from the evening:

NGC 5982 and 5985 (H400): A nice pair of galaxies. At 92x, 5982 is a small bright round glow, like a miniature M32; 5985 is an elongate, dimmer smudge of light. Excellent pairing.

NGC 1023 (H400): Big, bright, beautiful edge-on spiral galaxy, with clearly delineated core and bits of detail in averted vision. A minor showpiece!

NGC 2261, Hubble’s Variable Nebula (Caldwell 46): Very cool V-shaped spray of bright nebulosity. Edges of ‘V’ are very sharp and crisp, and the middle of the fan fades out evenly. Not like anything else I’ve seen in the sky.

NGC 2362 (H400, Caldwell 64): Open cluster. At 37x, almost perfectly triangular scattering of about 20 equally bright stars around a much brighter central star. One of the prettiest open clusters I’ve seen–better than many Messiers.

NGC 2024 (H400): Big, detailed bright nebula adjacent to Alnitak in Orion. At 57x, looks like a ghostly version of its photographic appearance. Extremely cool.

I was using my XT10 for almost all of my observations. I also had 15×70 binoculars along and they came in handy for working out a couple of tough star-hops and for observing IC 342 (Caldwell 5)–this galaxy is so big and diffuse that it was difficult to make out in the telescope, even at low power, but it was a cinch in the binoculars.

But my favorite observation of the night, and one of my favorite observations of all time, was made with naked eyes. About 12:40 I leaned back from the eyepiece and just stared up. Right at the zenith, between the Pleiades and the constellation Aries, was a very large, faint, and diffuse patch of light. I called Darrell over to ask him if it was what I thought it was. He thought so, but wasn’t entirely sure, so we asked Steve Coe, and he confirmed it. We were looking at the gegenschein.

Gegenschein, Shine On

The solar system is full of dust. Very little if any of this dust is left over from the protoplanetary disk that gave rise to the planets; that should have spiraled into the sun long ago.  Most of what’s out there now is thought to have been “processed”: incorporated into planetesimals early in the formation of the solar system, and redistributed by meteor impacts, asteroid collisions, and the evaporation of comets. The planets do not revolve through empty space, but through a flat disk of dust that encircles the sun like a phonograph record.

Under very dark skies, this dust is visible, for the same reason that the planets are visible: reflected sunlight. The brighter manifestation of the reflected dust-light is the zodiacal light, which stands up like a pillar from the horizon. It’s called “zodiacal” because the dust, like the planets, orbits in the ecliptic plane, which is projected against the background stars that make up the constellations of the zodiac.

The gegenschein is another, dimmer reflection of sunlight off the interplanetary dust cloud. As the German term–“counter shine”–implies, the gegenschein is observed directly opposite the sun. Friday night the sun set a little after 6:00 PM, and Saturday morning it rose a little after 6:00 AM, so right after midnight the sun was directly behind us (as it always is midway between sunset and sunrise, wherever you happen to be). That meant that the dust grains right overhead were in full phase, the same way that the moon is full when it is opposite the sun in the sky.  Darrell, Steve, and I saw this full-phase portion of the sun’s dust cloud as that glowing patch of light directly overhead. I had read about the gegenschein, but I had never seen it before. It is so faint that even the smallest amount of moonlight, haze, or light pollution will make it invisible. Seeing the gegenschein is a sign that you’ve been under some of the darkest, clearest skies on Earth.

(There is one further step: some observers have seen the zodiacal light from both horizons extending up to the zenith, making a complete band of light crossing the entire sky, with the gegenschein in the center like a diamond on a ring. Those people have seen the entire disk of dust visible from Earth at that time. This is on my life list of things I most want to see.)

I pushed on to a little after 2:00 AM. I ended the night with 6 Caldwell objects, which pushed my total to 74, past the 70 required for the AL  club. I also observed 27 objects for the Herschel 400, and re-observed at least 21 Messier objects over the course of the evening. The Great Nebula in Orion looked better than I have ever seen it–the nebulosity just kept going on forever and ever, and the patch around the Trapezium was incredibly detailed. I saw a lot of amazing stuff Friday night, but the gegenschein easily takes the cake.

Star…Trek?

London and I have a deal on these camping trips: I observe all evening, and he takes me on a hike in the morning. He told me that yesterday’s hike would be a “bone hike”, and we’d be looking for bones, spiders, and scorpions in the desert.

There was a range of low hills about two miles to the west of camp. London was adamant that we were going to climb them. And so we did. The secondary summit of the hill on the left in this picture is the one we climbed. The entire hill was comprised of shattered rock and covered with cacti, and the farther we climbed, the worse it got, so we settled on the lower peak.

The round trip took three hours and with all the winding around we did we probably walked five miles. I would not have thought my little man would have the stamina, but he was a real trooper. He had even packed up the water we’d need for the hike in his backpack. Not bad for a five-year-old!

We saw plenty of cool stuff along the way: saguaro cacti, free-range cattle, a jackrabbit, ants of every imaginable size and shape, and lizards that zipped from bush to bush almost too quickly to see. London did find a spider–a baby tarantula that froze when we walked up–and a bone, the broken, sun-bleached tibia of a cow. So the walk was a success all around.

Fittingly, the Tuscon contingent at the star party had a bunch of specialized solar scopes set up on the sun. When London and I got back to camp, we went down to check out their setup. They invited us have a look. There was a bright active region and little spike-like prominences standing out from the edge of the sun like quills on a hedgehog. I say “little” prominences but the biggest were probably about as tall as the Earth is wide. It doesn’t pay to get too blase about anything up there, especially our closest star.

Until Next Time…

It’s funny, when I’m back in civilization I spent too much time mooning over gear (New Year’s resolution notwithstanding). But when I’m out under dark skies, gear is the last thing on my mind. The telescope just gets out of the way and I am alone with the stars. It’s easy to slip into a productive rhythm–checking the charts for the next object, working out the star-hop, trying different magnifications to see which will make a given object show up best, taking some time to really look for details, recording my observations…sitting back to look around and just exult in the majesty of the night sky. The time flies by, always faster than it should. Strange, how thoroughly I can lose myself finding things in the sky.

This weekend might have been the end of the fall star party season.
California’s rainy season is upon us.  There will be clear nights and plenty of good stuff to see for the next few months, but it will be catch as catch can. Still, I’ve had a great run this fall, and I can’t wait to see what’s next.

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19 comments

  1. Great account, Matt. You’re giving Mollise a run for his money.

    We all had a blast and wish you could have stayed another night! Tell London I said “Hi!”.

    Best,

    Darrell


  2. Sorry I wasn’t able to get up there from Tucson. It would have been fun to meet in person.


  3. Thanks for the kind words! I’m hoping to come back out to AZ for the Messier Marathon in the spring. Fingers firmly crossed…


  4. Wow, what a night you had! I was out at Kelbaker with Cliff S. We got some good observing in. I noticed some unusual activity in the equatorial belt of Jupiter. Steve


  5. Hey! There is me sleeping in my car behind the solar scopes!

    Cool blog. Looks like you guys had a good time.

    Darrel sold me a scope too! I did not even know he was there.

    Marc.


  6. […] a fairly epic run of observations in November, crowned by the All-Arizona Star Party, I hardly knocked the dust off my scopes from Thanksgiving until early March. But I recently broke […]


  7. […] and I went camping at the Salton Sea. It was the first time we’d been camping since the All-Arizona Star Party back in November,  and my first serious observing since then, […]


  8. […] Vicki in a hotel room on the latter trip), Joshua Tree Lake and Afton Canyon in October, and the All-Arizona Star Party in November. And we’ve already been out once this year, to the Salton Sea again (the Salton […]


  9. […] a half. Between July and November we went to Owl Canyon, Joshua Tree Lake, Afton Canyon, and the All-Arizona Star Party, so we basically built out from nearby destinations to farther ones. The hardest part for him […]


  10. […] and I was anxious to see what the Mak could do. Mount Baldy is not stupid-dark like Afton Canyon or western Arizona, but it’s not bad at all. The Milky Way was prominent and showed a fair amount of detail, […]


  11. […] Distant rocket launch–one of the highlights of the 2010 All-Arizona Star Party […]


  12. […] list are the annular eclipse and the Venus transit from earlier this year. Other highlights include seeing the gegenschein at the All-Arizona Star Party in 2010, watching the crescent moon pass in front of the Pleiades […]


  13. […] I were out in Arizona for the 2012 All-Arizona Star Party. We’d been to the 2010 AASP–one of the finest nights of stargazing of my life–but we missed it last year, so it was great to get back out there. Terry Nakazono […]


  14. […] Arizona for the All-Arizona Star Party. This was our third such event–we also made it out in 2010 and 2012. London was more excited than usual about the actual stargazing. We took along his […]


  15. […] Gegenschein, which I saw at the 2010 All-Arizona Star Party, is another manifestation of the same phenomenon. Basically, the Gegenschein comes from […]


  16. […] place at the Hovatter Road airstrip in western Arizona. London and I have been three times now, in 2010, 2012, and 2013 (click on links for my observing reports), and we’ve always had a fantastic […]


  17. […] after bringing my XT10 to the AASP in 2010 and 2012, I brought the Apex 127 last year and now an 80mm refractor this year. At this rate, in a […]


  18. […] exactly one of these before – Steve Coe had shown one to Darrell Spencer and me at my first All-Arizona Star Party back in 2010 – but this was my first time catching one on my own. What’s particularly […]


  19. […] and Oxnard, some 20 miles distant, but for the most part the sky was dark. Afton Canyon dark, Hovatter Road dark – what I typically refer to as stupid […]



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