Hubble Ultra Deep Field (subset)

Club Address:
65-1158 Mamalahoa Hwy.
Kamuela, HI 96743


An electronic publication of The West Hawaii Astronomy Club

Club Officers:

Co-Presidents:
   Craig Combes,
   Craig Nance,
   Doug Summers

Secretary:
       Laura Kinoshita

With Support From:
Canada-France Hawaii Telescope and
W. M. Keck Observatory



This website is currently maintained by
Doug Summers

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E-mail: whacmail@yahoo.com

 


December 30th Dark Site Observing Report - Doug Summers

Our first "permitted" DLNR dark site observing session was held on the evening of December 30th. I picked up the key from the DLNR office in Waimea in the morning, and met the early arrivers at the dark site around 5:45 or so. Jack was already there, along with a couple of tourists from Seattle who had seen our Web Site star party notice. Jack brought his 10" Dob with him (new!), and I brought the DGT. We opened the gate and began to look for flat areas to set up. The site has received quite a bit of moisture since the last time I had been there....lots of vegetation. Here's some site pics:
entrance shot one.
entrance shot 2.
entrance shot 3.
view toward road.
view south.
Puu view.

On the way to the site, I noticed a lot of clouds moving in, and these were the low altitude variety. Funny, the prior week had been gorgeous....no clouds of any kind! This wasn't going to put a damper on our first official time out...no way.

Shortly after we arrived, other club members started arriving as well. Within an hour or so, Craig C., Mark, Kyle, and Remi had arrived & began setting up also. Here's some pictures of them with their toys (Mark's setup is behind Craig's, and the tourists are prominently in the foreground):
Craig C's ultralight.
Kyle's GPS scope.

Within a short time, we had all picked out the "flattest" possible spots for our scopes. "Flat" as described here meant finding a place where the a'a could be filled in with smaller a'a to get a semi-flat area. The site currently lacks some good setup areas, but we managed to set up 6 telescopes just fine. We then all waited for the clouds to clear. We waited and waited, but to no avail. At one point, it started drizzling! There were optimists and pessimists sharing their prognostications, and much laughter at each other and the circumstances. At some point, a fire-ring of chairs (without the fire) started, and we began wasting time.

I showed Remi a version of Megastar & the Real-Sky North & South plates. I was convinced that the plates showed stars to mag 25, but Remi was suspicious (being the professional that he is...he was polite). A quick experiment to go as deep as we could go in the Southern plates provided an estimate by Remi of 21st mag (max). I took the action to review at home to see what the real limiting magnitude of these plates are. The group spent some time talking on a wide variety of subjects (I missed some of this because I was fiddling with my gear). A few of the group then spent some time looking at each other's gear. Jack's new Dob was of particular interest...it has some very nice features in it that prove the new manufacturers are reading the popular magazines & attempting to make better gear. Kyle showed me his GPS goto scope, but alas, with the clouds being so thick, it wasn't much of a tour. I made a mental note to spend some more time with Kyle & see this scope in action, since I've not had much exposure to the new GPS scopes yet.

On two or three occasions, the stars peeked out of a sucker hole, and there was renewed prognostication that we'd be in the clear by 10 (famous last words). With the clouds being so low, every car that came on the highway would throw out a huge beam that covered the entire site. Everyone was wondering how we could have selected a site like that I'm sure. A few of us spent some time with Craig C & his scope; however while he was tweeking it, it was tweeking him! While we were all standing there, we heard a POP sound. I didn't think much of it, but Craig wasn't happy right away. Turns out that one of his glue points had failed on a pole, so he was done for the night. I hadn't realized how thin his mirror is; the whole scope is 27lbs (contrast that to the 185 lbs of the DGT!) Craig hung out waiting for clear sky with the rest of us afterwards. I used sucker holes to align my scope, but discovered that the azimuth encoder wasn't working right. Some few minutes of field testing later, I discovered that the encoder was acting like the old 8192 step encoder I supposedly replaced (not the 10000 step encoder I thought I had installed). More waiting & shop talk by everyone.....it wasn't getting any better.

The sucker holes were coming & going, but mostly going. The two tourists from Seattle began to think about heading for drier weather. We suggested they head out for the VIS & see if it was any better. Off they went. Finally, folks began to think about leaving. I can't remember what order they all left in, but I think Remi left (kid in tow), and then everyone else. Kyle was a trooper...he wasn't feeling completely well, but hung in there waiting with the rest of us. Eventually, everyone decided it wasn't going to happen and we all left & locked up. Right as we were locking up, we ran back into the Tourists; they had returned to tell us that there was clear weather just down the road. Our Clouds were a local phenom. Sure enough, as we left, we noticed within 5-10 minutes of the site a very clear sky. We were jinxed by a Kona funk.... our night was doomed from the start by the absense of any trade winds and the early Kona breeze bringing clouds to our site.

The next day, I was so irked by the bad weather, that I resolved to go back out to the site and try again. Two nights later, I went & set up with the DGT (I set up on Craig C's site...nice & flat!). This time, the sky was perfectly clear, and a crescent moon added just the right amount of setup light to help me get aligned. I had fixed the encoder problem found the previous outing, and had prepared an observing list expected to be 150 objects (all the way into Leo). Methodically, I began to work the list. I was recording voice notes using Kellee's MP3 player for every object as I went. Six hours later, I had observed 155 objects. The sky behaved very well (although the seeing wasn't the greatest....I estimated from the seeing star list that I was only getting about 2.5" of seeing at the site for this night. Transparency was good though, and the views of extended objects like galaxies were fantastic). I was exhausted. The night had proven to be one of the finest nights I've ever spent under the stars. I think 155 objects is a personal best....just me and the stars and the hum of the DGT fans. Kellee was fast asleep in the truck. By 1:30am, I had finished with Leo and was ready to call it quits. The only hiccup of the evening would be discovered the next morning. When I tried to retrieve all the voice files on the MP3 recorder, they were gone. Via circumstances I still don't know how to reproduce, all the files were gone. I was sick, but hey....the stars will always be there for me to do it again. So, I'll just finish up by noting that when clouds are present at this site, car lights will spill out light affecting the viewing. However, when clouds are gone, the site is extremely dark....I never saw any lights from cars affecting the quality of the sky on my subsequent outing. If you look directly at the road, you'll see cars go by, but otherwise, they don't add ambient light sufficient to notice in the eyepiece. I took a few pictures of folks out at the site (and of the site itself), I hope you enjoy these. I'm looking forward to a lot of great observing at this site...it is truly special (when there's no Kona wind). I'll get the pictures posted later this weekend and/or before the club meeting.

p.s. After going back home & rechecking the RealSky, Remi was pretty close.....the actual limiting magnitude is 20. Megastar allows filters down to 25th magnitude, but of course has no stars that faint in the program. So, there you have it. However, if you've never seen Megastar/RealSky in action, it's pretty neat even "only" for 20th mag.

Cheers, Doug



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