Your priority is not high enough and other targets with higher priority
are accessible at the same sidereal times as are yours.
If your targets have priority 2, they tend to be observed more towards the
middle of the trimester, and if your targets have priority 3, they tend
to be observed more towards 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 the
Program Statistics 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 should
Program Statistics and click on your active target to look for such conflicts, or if stumped send an inquiry to the RAs.
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.
Last updated: Sun, 08 Jan 2012 18:47:41 -0600 caldwell