Amy and I chatted for a few hours, and I finally turned in around 4:00 AM. I was tired, but not unhappy to have stayed up later than I planned, since I need to shift myself over to a night-time schedule since I'll be observing all night tonight and tomorrow. My plan was to sleep in as late as possible to try to make the adjustment, and I managed to sleep until about 1:30 PM. Coming down to "breakfast" around 2:00, I found (to my surprise) that Gary (my collaborator from Britain) was still awake, so we chatted a bit about how last night's observing went.
The weather had not been great (I had already learned this from Amy, who is observing the first half of the night on the same telescope). But it turned out that Gary and Bob managed to accomplish a surprising amount. This is good news - this kind of weather would have stopped us in our tracks when we first started this research project about six years ago, but the new camera is sensitive enough that we can get good data even in weather that's not so great. At the wavelengths where we're observing, the atmosphere is not very transparent, so even a little bit of water vapor in the air cuts out a lot of the incoming radiation. That's why we're here on Mauna Kea - it's one of the few places in the world where one can even make this type of observation. It has two big advantages: elevation and climate. At 14,000 feet, we're sitting above a lot of Earth's atmosphere, so it doesn't block our view. And the climate is quite good, in that it's extremely dry up here. Dry is probably not what you think of when you think of Hawaii, but on top of Mauna Kea the climate is essentially that of a desert. The moist air that comes in off the Pacific typically comes part way up the slopes of the mountain and then condenses to form clouds at an altitude of about 6000-8000 feet. And the dry climate affects the observers, too - I've had a bit of a headache most of the day, probably from dehydration. I'll try to drink more fluid tonight.
And what did we find out from our observations last night? Well, like a lot of scientific projects, the results aren't cut-and-dried. Several of the binaries showed detectable submillimeter emission, meaning that they definitely have disks. And those disks may be big enough to form planets, and least relatively small planets like the Earth. But several other binaries did not show any emission, so it seems like they don't have substantial disks. So we don't have a broad, general picture of how these systems behave yet - we need more data.
Our observing tonight doesn't start until 1:30 AM - unlike most telescopes where the visiting observer would have the whole night, the JCMT observing is divided into two shifts: 5:30 PM - 1:30 AM, and 1:30 AM - 9:30 AM. Part of the reason for this is that when you're observing at wavelengths that are far outside the visible spectrum, sunrise and sunset don't mean much. The sky emits relatively little submillimeter emission even in the daytime, so we can continue to observe after the Sun comes up (as long as we don't point the telescope straight at the Sun!)
The telescope operator stopped by our table at dinner and said that the weather for tonight looks somewhat better than it did last night, so I'm optimistic that we can accomplish a fair amount. But first, I'm going to try to catch a few more hours' sleep before we head up the mountain.
More later,
Eric
Eric Jensen <ejensen1@swarthmore.edu> Last modified: Sun Jun 8 16:15:27 2003