Changing Details of Approved Programs

It is recognised that some PIs may wish to modify observations after the ITAC-recommended queue and schedule has been approved by the Director. This might occur, for example, due to a change in scientific or technical priorities or a genuine mistake in the Phase I proposal (e.g. incorrect observing condition constraints).

Requests for change may be made by the PI to the Head of Science Operations for the relevant telescope (ijorgensengemini.edu, brodgersgemini.edu) and copied to the program's contact scientist and the National Gemini Office to which the proposal was originally submitted. Genuine or accidental differences between approved Phase I programs and the detailed Phase II observations may be also be identified by National Office or Gemini Observatory staff during verification. These too will be notified to the Heads of Sci. Ops. and copied to the NGO.

If the change is "substantial", the Heads of Sci. Ops. will, at their discretion, contact the relevant ITAC member to seek a recommendation for approval or rejection of the change. Note that changes may affect other approved programs, creating new duplicate observations or altering their likelihood of execution. Examples of substantial change include:

• Change of observing condition constraints (to better conditions, including any changes to airmass or hour angle constraints)
• Change of science target (to an identifiably different source)
• Change of integration time (such that the total time of all targets is greater than the allocation)
• Change in observing configuration (to a different instrument or instrument mode)

Minor changes would not normally trigger communication with the ITAC member. Examples include:

• Refinement of target co-ordinates (for the same source)
• Modest adjustment of integration time between observations within the same Science Program
• Refinement of observing technique (e.g. to a subtly different filter, say, K rather than K')

The minimum (‘guaranteed’) interval for Gemini Observatory to act on a request for change is seven days. Final authority for resolving disputes over observation modifications rests with the Gemini Director.

Last update July 05 , 2007; Rachel Mason