CFH12k on the Sky!

CFH12k is sucessfully taking data; make that large amounts of data. The world's largest CCD mosaic camera is on the telescope and working very well.This would not have even come close to happening without the hard work and dedication of many CFHT staff members and Gerry Luppino of UH IfA. The CFHT staff involved in this heroic effort include (in alphabetical order): Reports from Jean-Charles Cuillandre on the last two nights (Jan 11/12 and 12/13) follow. The first night was straight engineering while the second was split with observers (Olivier Le Fevre and Olivier Boulade). Here are three sample images: small, low-res and high-res of M81.

Jan 11/12

A great success! I've never taken so much data in one single night;  not only is there a lot but it is all very good and shows that  the CFH12K is a highly efficient instrument.

You read Barry's email about the few glitches at the beginning of the night, but that night ended up with about 200 exposures taken on the sky (it means 200 activations of the shutter at various hour angles, some as extreme as 4:40!). Overall it is about 35  Gigabyte of data collected in 10 hours!

First of all, this night could not have been without the ultra effort put by Barry on the filter wheel. It works great and we control it from the session. A working filter wheel boosted my work by a factor of 4 at least, hence I I had time to look around in the sky at some wonderful objects I will share with you soon.

Sidik's software is rock solid, not one exposure was lost, none of  the systems had to be restarted. Now we are setting the high level interfaces to the telescope and the user.

Many thanks to Marie-Claire Hainaut (OA) for her high efficiency trough this frantic long night as we finished late with twilight flats and  dome flats in all 4 filters!

Christian Veillet was supporting us from down in Waimea, analyzing some of the data we were taking to prepare us for the next steps. This helped a lot in improving our efficiency on the sky. Here are some topics addressed tonight:

There are still some engineering work to conduct over the next two nights (but the main bulk of work has been
accomplished): Jan 12/13

Good Morning,

Yes, I do feel lucky: 0.55 arcsecond seeing data in the I band on 10 minutes exposures!

Actually it is just that we have a great instrument on a  great telescope.

The night started with the French observers who were very happy (or surprised?) that every went so well: not one problem and they already collected a large set of high quality data. Olivier Lefevre and Olivier Boulade both had a big smile on their faces! They got data down to 0.6" in the I band.

Thanks to automatic focus scripts and sequence observing scripts, the efficiency of the camera is very high: only 1mn30sec of overhead between exposures. We are really spending most of the time with the shutter open (typical exposure time is 10mn).

Then the second half-night was for CFH12K team. Residual images tests were taken on a star field, along with  some photometric calibrations. The dome temperature is  higher by 5 degrees compared to yesterday and the Z to  focus all 4 filters has gone down by 0.5mm. The increase of the CCD temperature is related to this external increase. We will have to set a higher working point for the temperature regulation for the next run (let's keep it like this for this run).

Three fields were taken for Christian during the night, and I got to observe a field in B and I. Hell, I got 0.8" in the B band (8x10mn  exposures) and then 0.55" in the I band! This is great stuff.  I hope to successfully complete these observations tomorrow as a high signal to noise ratio is required. We have  great sensitivity  (a 4meter telescope and thinned CCDs), and we have an  outstanding image quality that allows detecting small  and faint objects.

Oh, I forgot to mention: the camera behaved perfectly tonight.