20170121

Twilight Tests

twilights with VIRUS with different tracker positions

Purpose: There is some interest in seeing what the long term illumination correction changes look like including what different track positions do to them. The script is "specialtwilight" in /home/mcs/astronomer/bin/. It takes a single argument which is the Observation number.

Procedure:

• Despite of pressures at the start of the night try to get the twilights.
• Setup the guide camera for sky twilight (GC2, 0.1 sec, B filter)
• When you hit the correct flux level (biased to a slight higher value, perhaps 5k) execute the specialtwilight script

On-sky science:

There is quite a lot of unobserved targets in the West in the Shelia field.

Right after twilights ask for a quick stack, just a few iterations on each side. Please give the TO the time you want to be moving to the target.

• Try to observe a complete visit to a UT17-1-011 target at 01:20. Give pri=1.00 preference (over pri=1.30), . A good target would be index=3783 (SHELA_v095b_z4_1536384).
• Both LRS fields should be observed with a Parrallel command. $HET_SRC_ROOT/integration/parallel-exposure.py --help for an example $HET_SRC_ROOT/integration/parallel-exposure.py -p lrs2 -t sci -i 850 -N SHELA_CL1147B -O 2 -E 1 -o 3 -e 1
• If you get the index = 3783 then on the next night try to hit a UT17-1-014 target (CL2132A note that there are two identical entries) at 01:05 UT followed by any UT17-1-015 HF VIRUS target at 01:50 UT for 2 nights in a row.

After these two targets allow the TO some time to do a full stack.

During any thin parts of the night (few targets) please try to get your standards.

When VIRUS targets are available they generally should have priority over regular targets (except for the pressure at the start of the night described above.