The clouds were spectacular this evening, both to the east of us (above) and to the south (below). Fortunately by the time it got dark there were none overhead. We also tried to spot Comet C/2009 R1 (McNaught) but had little luck as it was lost in the twilight sky. Andrew Cooper may have had more luck tonight.
There's been a noticeable decrease in the number of comments recently, I hope I haven't said something offensive or anything like that! If it's down to a lack of content, then I definitely understand, I just hope those kind enough to read my posts understand things have become incredibly busy recently and it's hard to find time to put much thought into what I write here - so it's pictures instead!
It's easy to forget we work on top of a volcano. Mauna Kea isn't active but is classified as dormant - certainly not an extinct volcano. It last erupted around 4,500 years ago but it will likely erupt again. No one knows when. The cinder cones that litter the summit area and the rest of the mountain bear testimony to a time not long ago when the mountain spat fire.
As the sun sinks below the horizon astronomers at Mauna Kea's summit start to work, the tourists leave for lower altitudes and the sky takes on some amazing colours. There comes a time when the light from the sun can no longer illuminate even the highest clouds and it tends to happen very quickly. One moment the cirrus clouds are bright red and the next they're a dull grey.
One or two people have said they're not bored of summit photos just yet. So here are a couple more. Just be aware that I'm running out of photos again!
A rare photo of Subaru actually opening at sunset. They always seem to open much later than the other observatories. I'm not sure why. What's even rarer is the Kohala coastline being visible from the summit. As you can see in the top photo it's usually hidden by clouds.
It's well after sunset but the horizon still shows the glow from the sun, at least on long exposure photos! Subaru is the telescope in the foreground. The dome is metallic coloured and often turns a golden colour at this time of night if there are high clouds around to reflect the red light. On this occasion, however, the sky is clear and the dome takes on a less interesting grey/silver colour and a lot less contrast to play with.
Some of us start the night shift early. The dome is opened well before sunset to help equalise temperatures inside and outside the dome. Sometimes the IRTF, pictured above, is opened early as it's observing a planet that's only visible during the day.
Other observatories tend to wait until after the sun has set, the Kecks being an example. Although I'm not familiar with the Keck's policies, one thing you must avoid doing if you open early is having direct sunlight on any of the telescope structure. Even at sunset or sunrise when the sun is low in the sky, the light from the sun will warm the structure it strikes and some expansion will take place. It'll be tiny, a few microns perhaps, but enough to effect image quality.
I don't know, I'm getting a little bored of these. Same place and usually the same time (sunset). They look nice but I need to find something else to take pictures of especially as summit time will become rare after this year. The thing is I suspect I'll be busier than ever then, so may not have a lot of time for taking photos. I don't even have the time right now unless I'm on the mountain, and then it's a limited period of time during the day.
Or lighthouses?
Flowers?
The strangest Cornish Pasty I've ever eaten? (The tea was first rate though).
I'm open to some ideas and challenges!
There are still a few minutes to go before sunset and the summit tourists are preparing for a treat. Most payed something like $200 to be taken to the summit with a tour company and although that's an awful lot of money they are treated very well from what I've heard. On the way down they get to see the amazing night sky from either the Visitor Center at the 9,000 foot level or the tour company will provide telescopes for viewing from some of the other dark viewing spots on the mountain.
Even the astronomers and those that work at the observatories want to watch the sunset. In the top photo you can just make out the staff standing by the Gemini mirror inside the dome watching the magical view, and in the one above, the observing team for the night are outside taking in another amazing evening view from the CFHT.
The last few nights have seen some bizarre changes in observing conditions. We've gone from some relatively average conditions (seeing around 0.6" for those who know what I mean) to absolutely stunning seeing (~0.3", natural) and within half an hour to a terrible upper atmosphere that our guider couldn't cope with followed almost immediately by a mini ice storm and freezing fog. Tonight the seeing remains awful and highly variable but I'm sure the atmosphere will sort itself out soon.
With a weather system moving in the inversion layer is much higher this evening and there's a lot more low level cloud. This means, unlike yesterday's amazing view, there's no ocean visible from the top of Mauna Kea. Instead, we have to make do with some of the other sights we get to see at sunset, such as the shadow of the mountain and anticrepuscular rays above, and below, colourful cirrus clouds to the west.
Light from the setting sun reflects off the Pacific ocean thousands of feet below while crepuscular rays bathe the distant Kohala coastline. The silhouette of the Subaru Observatory sits in the foreground.
Fortunately I'm not holding a large bolt in my hand and asking the engineers if they know which bit of the telescope it came from. Our engineering team put everything back together so precisely after our recent realumunisition work (see here and here) that tonight it was hardly necessary to make any adjustments at all in order for us to take science data again. We were doing science observations just an hour after sunset on our first night back when in fact we had scheduled two and a half nights of engineering to get us up to speed again!
"Minimalist mode" almost sounds like some sort of new art fad or perhaps a new way of cooking nouvelle cuisine, but it's the term that's being used to describe the new operating mode that UKIRT will switch to at the end of the year.
UKIRT's primary mirror emerges from the vacuum chamber where it had been coated with a few hunderd Angstroms of aluminium (and I'm going to use the American word aluminum from now on!).
This infrared scatterometer is what we used to confirm the quality of the new coating. Unfortunately it's rather unstable and as usual when scientists and engineers get together all sorts of theories, solutions and experiments were discussed, but finally we agreed that the mirror surface was giving us the same result as if it had been coated in gold.
Erik, one of our engineers, is pretty proud of the result. He's been working here almost as long as I have by the way! The odd looking striations on the mirror had me panicing at first when I saw this picture, but they're simply reflections from the lab's wall. At least we know the mirror is reflecting stuff, which, after all, is what it's supposed to do!
The mirror is very gently lifted from its support in preparation for its transport to UKIRT. I had asked our chief engineer beforehand if I needed to wear a hard hat while I visited the CFHT and he said that for this part of the work I should wear one. He then pointed out it'd probably be no use other than to help identify me after an accident. Now I know what he meant! This is several tons of glass being lifted.
Finally, after a few hours, the primary is slowly lowered onto the truck. Everyone here is being extraordinarily careful because we can't risk any damage. We don't have a spare primary.
Off it goes back to its home at UKIRT accompanied by our own security detail!
Convoy!
Below are a couple of images from this evening. They were taken from the webcam placed on the edge of the crater of Pu`u O`o. From Mauna Kea's summit today the plume from Kilauea's summit was very obvious (above) yet I couldn't see any plume from Pu`u O`o which is an active crater a few miles east-south-east of Kilauea's summit. It might explain why the webcam images are so clear right now because usually all you see is the thick plume.
Live Panorama of Halemaʻumaʻu Overlook Vent, Kīlauea Volcano
