While preparing Cycle 5 proposals with targets in bright crowded fields, such as the Galactic Center, some JWST users have reported that the Astronomer’s Proposal Tool’s (APT) Visit Planner is unable to find guide stars. This is because of changes in the guide-star selection criteria. These changes have improved the execution of observations in crowded fields, but currently make the observations appear non-schedulable in APT, even though guide stars are available. 

STScI encourages users in this situation to submit their proposals, providing a comment in APT about why they are submitting an un-schedulable program. If the proposals are successful, the Program Coordinators will work with affected PIs to select the guide stars. 

Users with questions about guide-star availability for their programs are encouraged to contact the Help Desk. Make sure to check the Call for Proposals Late Breaking News section for this and other information relevant to JWST users.