Instrument Availability and Target Accessibility: 2004B

The tables below indicate the current best estimates of instrument availability and corresponding target (RA, dec) accessibility for 2004B. Typically several observations or programs are rejected at the ITAC each semester because of target accessibility so please read carefully the following notes:

• For each given declination, the table shows the target RA that has two hours above airmass = 2 at the start of the night early in the semester ("minimum" RA) and the target RA that has two hours above airmass = 2 at the end of the night late in the semester ("maximum" RA).
• For some high and low declinations (noted *), an airmass limit of 2.5 is used.
• If best image quality is desired, typically achieved at smaller zenith distance, the RA range should be reduced appropriately.
• The comments column indicates whether all RAs are potentially observable. 
• "no restriction" means that all RAs are potentially observable. 
• "restricted" means that only RAs between the "minimum" and "maximum" can be accepted for observation in this semester. Targets with RA less than the "minimum" will set too early in the night and cannot be observed; targets with RA greater than the "maximum" will rise too late in the night and cannot be observed.
• At the extrema of the RA range, shown by the early- and late-semester values, targets may not be observable in practice due to detailed instrument and engineering schedules and other constraining factors (e.g. lunar phase). Moreover, the time for which the target (RA, dec) is accessible may be very limited and applicants should bear this in mind for faint targets. The likelihood of execution is greatly increased if extreme RAs are avoided.
• In some cases, an instrument or instrument mode is forseen to be available for only part of the semester. Such instances are listed after the main table. 

Last update February 23, 2004; Phil Puxley