Tuesday, 16 February 2010

Winds aloft

Not one of the prettiest sunset I've seen but nice nevertheless. Again the lack of high clouds meant the sunset wasn't as spectacular as those we were getting this time last year. I caught the sun just as it set behind the distant clouds to the west.

Subaru also put on a bit of a show with the last rays of sunshine falling on the dome and surrounding structure - it looked quite pretty!

You might think the clear skies would be good news for us, but we've had an interesting night so far. There is a trough to the north of the island which is causing high summit-level winds so we are trying to point away from the wind and let the dome shield the telescope. This limits our options as to what we can observe. To make matters worse, the trough is also increasing winds aloft to something like 150 mph and we are seeing a lot of turbulence and shear in the atmosphere. This degrades the image quality (seeing) significantly. By this time of night we'd be hoping for 0.5 arc second seeing but we've been getting more like 1.5 which is pretty unusable for us. Having said that, we seem to have just found a patch of sky which isn't too bad, so at least we're getting some useful science done.


Andrew Cooper said...

It was nice last night, and almost exactly the same sunset whatever elevation you were at. I watched the Sun set into the same distant layer off clouds from 9,000ft lower down the mountain. When the last bit disappeared I turned and saw just a hint of glow on the Keck and Subaru domes. Odd to see your photos posted from a different vantage but the same event.

Tom said...

I need to get over to the leeward side a bit more often. Although I love sunrises and this side is the place to see them, I'm not a morning person!

I'd like to try 1) some sunset shots from the west side of the saddle and 2) from the leeward beaches!

As for the glow on the Subaru and Kecks, you definitely still see that after the sun has set and it's very attractive to the eye, at least for me.