Wednesday, September 25, 2013

Good to go!

In spite of significant weather loss during the engineering nights scheduled for the AdSec-DX checkout, we were able to check the system out in all four binning modes and the system showed reliability and stability. 

From the tests made, the system is deemed in a reliable enough state for the upcoming PISCES run, scheduled for 7 nights (Oct 8 to 15).

A pre-run engineering night scheduled for PISCES checkout will allow for more tests of the secondary mirror.

Note: This blog is likely to come to an end soon!

Tuesday, September 17, 2013

First light for the new thin shell!

Another important step in the AdSec-DX recovery effort was reached on Sep 15, when the unit with its new shell (TS4) saw a real star for the first time.

Starting on Oct 13, three days of intense work were spent installing, testing and tuning the various reconstructors prepared in Arcetri by our Italian colleagues, and computing interaction matrices... A mask was also installed, as planned, on the thin shell central hole dust cover to hide the mouse hole.

 The dust cover before the installation of the mask. The mouse hole is seen on the left of the cover

The mask is now clamped on the dust cover, covering the mouse hole

On Sep 15, day-time results looked very promising and the team went to the sky for nearly two hours of clear weather before observations had to stop for high humidity for the rest of the night. The new reconstructor slaving all actuators of the internal ring was used on a Rmag = 6.7 with seeing values in a range from 1.0 to 1.8 arcseconds. Correcting for 400 modes yielded the image below. The strehl ratio in H is 87%.

The good news is that the modal basis, optical masking, and WFS digital masking introduced in the new AO software are able to deal with the warping of TS4 in the central region.

More tests to come, weather permitting!

R. Briguglio, L. Busoni, S. Esposito, A.Puglisi (Arcetri), J.C Guerra and J. Christou (LBTO) are the actors on the Mt Graham