Comm2 Day 8: Airy airy

Tonight was our second night on-sky this run, and we have been accomplishing many engineering tasks. With the AO system, we have been testing and optimizing our AO parameters. Here is a PSF from yesterday, with only ~100 nm phase rms WFE:

61% Strehl at z’, closed loop with 378 modes.

With VisAO, we are calibrating our photometric system. With Clio, we are focusing and testing the pupil masks. And Vanessa has finished adding the AO and TCS keywords to the FITS headers, and it turned out to be very useful! Thanks, Vanessa!

Here are some images in M’ from Clio with the apodized-phase plate (APP) coronagraph:

A bright star imaged through the M’ APP coronagraph.
A binary star imaged through the APP coronagraph. (Ignore the ghost)

Look at all those beautiful Airy rings! It’s a pretty great way to do coronagraphy on a binary star, because the APP is a phase mask placed in the pupil plane, so it attenuates the PSF of both stars.

Well, these nights are long since it’s getting to be winter, and so I’m really tired… let’s finish with some more pretty pictures:

A guanaco gazes at the 100”.

This sunset picture shows a diffraction spike and ghosts and flares, just like the Clio image.
Sunset at the Clay was exciting tonight — a few of us believe we saw the green flash for the first time!
Looking to the east after sunset, the sky was just gorgeous.

Some quotes from today:

“You’re not doing astronomy if you don’t have to do everything twice” — Dave Osip

“I’m not going to give you any more quotes for the blog” — Povilas

“Do you know the ratio of the ghost?” — Laird
“Which one?” — Clio team, in unison

“I know my Astronomy!” — Vanessa

“Hold on. Let’s talk about what’s really important. Did everyone get
empanadas for their night lunch?” — TJ, interrupting discussions of
observing logs.