Some clouds around, mostly clear.

High frequency readout noise can be seen in the images.

All darks before 0019 are bad - blank mask was not in, light in dome

good darks 60sx2 are 23-27

darks 4s are 28-32

6:29pm start sky flats

J-band flats are 33-42, counts ~13,000

J-band flats 43-52, counts ~5,000

6:43pm finished sky flats

6:58pm collimated, ~0.9" median seeing, background still bright

7:00pm Started integrating on 0850 (Ken's target), first image is 0053

8:10pm First noticed some smearing of images, changing over field and with time, might apply to all previous images. Seeing still looks good (~0.65")

9:30pm Stopped integrating on 0850, switching over to COSMOS (Linhua's target) for spectroscopy

9:32pm COSMOS acquisition

9:46pm Started integrating with longslit on target, seeing ~0.8", first image is 0117

10:02pm Pickup noise not apparent in spec data

10:19pm Some clouds, might be clearing soon, it is not very bad. the seeing is 0.7-0.8"

11:52pm New sequence of exposure. the seeing is 0.6"

12:41am seeing is 0.5" to

1:58am go to the standard ukirt_fs128 good standard star

2:38am go to J1306. seeing is 0.4"-0.5''

6:10am The observing is done.

-- XiaohuiFan - 03 Mar 2013