A night on the (not-so-bare) mountain
Morning. Or evening. I’m not sure, you see. Living in three different time zones does that to you. There’s UK time, which my body is still just clinging to. Local Hawaiian time, too, and nocturnal time which means that it’s 7pm at night and time to get up.
We drove halfway up to mountain to the astronomer’s residence yesterday, spending a night here to get acclimatized before heading on up to the summit. Needless to say, last night was absolutely stunningly clear, one of the darkest skies I’ve ever seen. I was reminded of something someone in Chile said to be – ‘really good skies are grey’ with all the starlight, and last night definitely was. Seeing the Milky Way overhead stretching down into Scorpius was just stunning, especially with Jupiter high in the sky instead of hugging the horizon as it does at home.
So my hopes were high for tonight’s observing. However, I woke up this evening to find that we were sitting in the middle of a cloud. This isn’t necessarily bad news – the summit’s clear conditions rely on the inversion layer, a band of cloud which sits almost permanently around the island. So cloud here might mean that the summit is perfectly clear – but we should head on up and see. Keep an eye on us here (scroll down for the webcams).
Update 20.27 HST : Doors opening. Sky’s beautiful up here to the naked eye – Jupiter and Venus in the same sky, Crux just visible above the horizon.
Update 22:02 HST : Currently observing the molecule CS in the Antennae galaxies. The idea is that such molecules will help us understand the massive rates of star formation associated with such galactic collisions. Unfortunately we’ve got a computer problem so we’re stuck on this source for a while, and it’s setting…
Update 22:69 HST : Computer’s fixed, and we’re off to our next target, which is Sakurai’s object. Which targets we observe are determined by where they are in the sky, and also by the quality of the sky. As we’re observing in the sub-mm, nothing matters is the amount of water vapour in the air above us (which is also the reason to be so high up). That means that it’s possible to walk outside and see a perfect sky, and come back in and see terrible conditions – which is what we have tonight. So we do other people’s observations, and they’ll do ours, and in the meantime we’re working on data taken for our project on previous nights.
Update 1:23am HST : We’re still looking at Sakurai’s object, looking for hydrogen cyanide. This is usually used as a tracer of high density gas, but I’m not sure what it signifies in this object. I’ll look it up when we get a second. We’ve finished the rough analysis of our data on the Antennae, and are fairly confident we have a detection of CS, which is pleasing. Almost half way through the shift, and I’m going to take a walk outside shortly.
Update 3am HST : It’s cold and clear outside,but the weather from the sub-mm point of view is worse than ever. There must be some wet air up above us. As a result, we took the only decision we could in the circumstances and have switched to rock music to stay awake. Look out for air guitar on the webcam.
Update 4:09 HST : Finished our integration on Sakurai’s object (finally) and have moved to the variable V605 Aql. About which I know nothing, but if I get a second, I’ll find out for you. Feeling reasonably awake, and I haven’t attack the coffee yet either.
Update 4:55 HST : Found the science proposal (the things we spend hours writing to be allowed to get here in the first place) for the project we’ve been observing. It turns out that the objects we’ve been looking for are ‘born-again’ giant stars which were once quietly heading toward being white dwarfs. In about 20% of cases, for reasons that aren’t clear, the stars suddenly flare up again. This normally takes a couple of centuries, still pretty fast for astronomical objects but Sakurai’s object managed it in just a couple of months about a decade ago. Why look for HCN? If I’m reading this right, the stars throw off a shell of dusty material, and HCN should be contained there. Right, off to see the sunrise…
Update 6:06 HST : And it’s daylight out there. Subaru were still open when I went out, but there was a stream of other cars heading down the mountain as everyone else went home. The advantage of the sub-mm is that we can observe in daylight, so we’ve got almost three more hours on sky to go. We’re onto our third born again giant – tentative detections of the molecule we were looking for in both the others so far.
Update 7.32 HST : Feeling pretty tired now, but the view out the window is showing the beautiful red colour that I’ve only ever seen here and in bits of the South Devon I grew up in. And which I imagine covers lots of Mars. The Atacama desert was sandier, not quite so vividly red. In the meantime, we’re pointing (just) at our last science target, a high mass protostar. We’re looking for molecules that shouldn’t be there – the PhD student who wrote the proposal is trying to establish where molecules are still frozen onto the surface of dust grains despite heating from the central star.
Update 8:55 HST : The last science is done – the weather is the best we’ve had all night, and if this trend continues we’ll be observing the sources we came to see when we do it all again in about 11 hours time. The telescope is pointed at Mars to get an observation which will allow us to callibrate all of tonight’s data, and then we’re off down the hill. More tonight – probably picture based.
