It's been a hard day's night

I should be sleeping like a log! From sunset to sunrise tonight is thirteen and a half hours. For the astronomer, that is a long workday, especially to do five nights in a row. Ugh!

But, here on top of Kitt Peak, we have been working hard all night and getting some good data. It has been a crystal clear night with very steady skies.

I haven't had the time to put together a pretty picture yet, but I should have one tomorrow.