HET Beginning-Trimester Report
Third Period of 2021
August 1 - November 30

This report is primarily to give updates to PIs on recent changes/improvements and to summarize the determination of time allocations for the 21-3 trimester.

Updates on recent changes/improvements:

Updates to documentation

   Further information has been added to the "Observing Status" page on Hydra:
        https://hydra.as.utexas.edu/?a=help&h=7

   Acknowledgements for the HET and for each instrument are available here:
        https://hydra.as.utexas.edu/?a=help&h=61

Improvements to Target Submission Language (TSL)

Starting in 21-3 we have removed the keyword "NUMEXP" because of the confusion it caused with PIs.
Please use CRSPLIT and EXP. See the TSL help page for more information here: https://hydra.as.utexas.edu/?a=help&h=73

Commissioning, Engineering, and Guaranteed Time allocations

The HET Board granted the following allocations for the 21-3 period:

15 hours of HPF commissioning/engineering
10 hours of VIRUS commissioning

25 hours of HET operations engineering
10 hours of Image Quality engineering

8 hours of LRS2 Guaranteed Time Observations
20 hours of HPF Guaranteed Time Observations
157.5 hours of HETDEX Observations (7.5h from UT for TESLA)

Total: 245.5 hours

Breakdown of how science hours for TACs at each partner were determined:

quantity	Aug (hrs)	Sep (hrs)	Oct (hrs)	Nov (hrs)	Total (hrs)
18deg-18deg times	243.93	268.10	306.58	318.17	1136.78
Weather loss frac.	0.432	0.513	0.391	0.369
Efficiency loss frac. (align+PRs)	0.08	0.07	0.07	0.07
"Clear science" time	127.47	121.43	173.64	187.01	609.54
Com/Eng/GTO time					245.50
"Allowed" hours given to TACs for science					364.04

Hours allowed for each TAC as determined Jun 10, 2021:

Partner	Share	Notes	Total hours allowed	Allocated as of Aug 1
Goettingen	0.03860		14.05	14.1
Munich	0.05724		20.84	20.8
PSU	0.24897		90.64	87.6
UT	0.65518	-7.5h TESLA allocation per HET Board	231.01	231.13

Note that TACs may allocate up to 8.3% at P0, 25% at P1, 33.3% at P2 and 33.3% at P3; P4 allocations are not restricted. Priorities of Com/Eng/GTO time are assigned by the HET Board.

Also note that the PSU and UT TACs have sometimes elected not to allocate a small amount of time which can be allocated to targets-of-opportunity which arise later in the trimester.

SJ, 4 Aug 2021