Your priority is not high enough and other targets with higher priority
are accessible at the same sidereal times as are yours.
Historically targets with priority 2 were observed in the middle of the trimester and priority 2 in the last month of the trimester. With HPF utilizing the majority of night time hours from 2019 onward, this trend has somewhat reversed, with some groups submitting only priority 2 and 3 targets at the beginning of the trimester and waiting to use their priority 1 time until the end of the trimester.
Your Phase II observing condition constraints are relatively severe and
are not commonly attained. Take a look at a few night reports at roughly the UT
time when your targets are accessible. Compare the observing conditions present
with your Phase II specified conditions. You can review the observing constraints
of any active target in your program tab on Hydra by clicking on that target.
Your targets are competing for the same sidereal time slots with a large
number of other equally high priority targets. You are encouraged to reach out to the RAs for help and advice on this.
Why does my target have less S/N than I expected?
There are several possible explanations:
Did you use the latest S/N estimate? Make sure that
you used the latest estimates and that the wavelength you use is the same
as in the estimate.
Did the conditions in the night report match what you requested in your
Phase II or in your S/N estimate?
Was the target observed near the center of the track? See the
filling factor estimator
or download a code, called checkfill, to check the filling factor in your actual observation.
