--> Priority Visitor Observing | Gemini Observatory

Change page style: 

Priority Visitor Observing

You are here

Priority Visitor observing is offered to investigators of Band 1 programs. It is the default observing mode for Band 1 Large and Long Programs (LLPs). Investigators wishing to have their program considered for PV observing should indicate their desire to participate in the Technical Design portion of their queue proposal.

If your visit to Gemini NORTH is already planned, please read the Gemini North Visiting Observers Guide.
If your visit to Gemini SOUTH is already planned, please read the Gemini South Visiting Observers Guide.
Disclaimer: some links embedded in the document are only available internally at Germini.


In PV observing, a visiting observer is placed in the telescope control room for a block exceeding their program’s time allocation, and elects when to carry out their program within that block. This may be when conditions are within their requirement, better than their requirement or even fail to meet their requirement. Whenever they are observing, the program is charged for the time at 100%. For example, a PI with a 40-hour allocation in the semester could ask to be the visiting observer for six nights, and execute their own program during the best 40 hours encountered. If time remains on the program after the priority visitor observing time is complete, the program carries on in the regular queue with priority given by the TAC-assigned science ranking band (1 or 2). For some programs requiring the best conditions, the observatory may start them in the queue before any summit time.


A priority visitor may also make some types of decision about their program in real time that would not normally be made by a Gemini queue observer. For example, a priority visitor may decide that catching targets before they set for the semester is more important than formally meeting the original plans for image quality, or may trade off exposure time for conditions to reach the true signal/noise requirement. Note that targets not included in the proposal cannot be observed without approval, and instruments cannot be changed.

The observatory may set an upper limit on the amount of additional visiting time a priority visiting program will be allocated. Priority Visiting Observers will be required to meet their contact scientist at the base facility, and obtain necessary familiarization on Gemini and instrument-specific procedures ahead of the run. From 2014B, they will be accompanied in the control room by two Gemini staff: a telescope operator and a trained observer (who may or may not be their contact scientist), and will be asked to take part in observing on programs other than their own as a test of the framework laid out above. During these sessions, information will be recorded on issues likely to impact on execution of queue programmes in the longer term (where priority visiting will be expanded to be available for general queue PIs and those PIs will be expected to execute the queue across multiple instruments).


Additional notes: approved targets of opportunity may interrupt the execution of a priority visitor program. Priority visitor runs will be scheduled to avoid extended time-critical observations as far as possible.


Gemini Observatory Participants