NOTE: This calendar is out-dated and does not include HETDEX conflicts. It is retained only for legacy purposes but should NOT be used when preparing proposals!
Please use current observability calculator located here:
https://het.as.utexas.edu/HET/hetweb/ProgramPrep/hetdexcalendar.html
This program enables a PI to determine the calendar dates, and the times on those nights, when the PI's targets can be observed. This program takes into consideration lunar position (up or down) when the track is available, track length, and the type of twilight cutoff to use (18 deg for dark, 12 deg for bright).
It does not output nights when no track is available, nor does it output tracks when the moon interferes with (being present in excess of the constraint) enough of the track that the requested visit cannot be completed. If the moon interferes part-time but the requested visit can be completed, then the track will be output but showing the constrained track length.
Enter the RA, Dec, exposure time, setup time, lunar phase, requested period, your host institution, seeing and transparency limits below and hit the submit button.
If you are not familiar with these criteria try looking at the HET Phase II Criteria or The General HET performance pages.
(as of Nov-2022 these buttons have been disabled - contact HET operations staff for any assistance required)
NOTE: This calendar is out-dated and does not include HETDEX conflicts. It is retained only for legacy purposes but should NOT be used when preparing proposals!