Night swaps on the 1.2m telescope are a frequent occurrence. In 2006, the 1.2m with Keplercam has obtained a significant number of successful, useful observations of planetary transits. Several PIs have participated in these observations, including Dave Latham, Gaspar Bakos, Matt Holman and Dave Charbonneau. The observations require scheduling on particular nights and usually cover at least one-half of a night. Other projects such as measurements of SN lightcurves or follow-up of NEOs also impose tight constraints on the schedule. Several other projects compete for the remaining time, but with less time criticality than those listed above.
Because of the success of the telescope, we are experiencing an over-subscription of about 60%. Thus, the TAC has had to trim time allocations, and scheduling has become more of a challenge than in past years. Because of the nature of transits and their predictions and of their growing rate of discovery, observers have swapped a growing number of nights. Transits usually allow sharing of nights. PIs have been extremely cooperative, but at times there may not be an observer available to cover a given swapped night. We expect the demand for swaps to increase in coming trimesters.
So far, swaps have been conducted informally and successfully, but there have been occasional glitches. We offer the following guidelines for swapping nights to continue efficient observations and minimize glitches.