Public Access Observing Time on the Hobby-Eberly Telescope

Caty Pilachowski and Tom Barnes, University of Texas and McDonald Observatory

Beginning in June 2000, the 9.2-meter Hobby-Eberly Telescope (HET) at McDonald Observatory will be available to the astronomical community for queue-scheduled observing. This time is made available under an agreement with the National Science Foundation administered through NOAO. The HET is a unique, queue-scheduled, segmented-primary telescope optimized for spectroscopic observations. The agreed amount of time is 101 nights of queue-scheduled observing time over six years. This community access time will be distributed over the phases of the moon and the seasons of the year in the same proportion as the scientific observations scheduled for the members of the HET consortium (The University of Texas at Austin, Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universitaet Muenchen, and Georg-August-Universitaet Goettingen).

Access to HET through the Public Access Program will begin in June 2000. Researchers should be aware that a month of summer shutdown of the HET is a possibility (July or August), with a decision in Spring 2000. Proposals for the period from 1 June 2000 through 31 January 2001 will be due on 31 March 2000. Proposals should be submitted through NOAO using the standard NOAO proposal form. Proposals will be reviewed by the NOAO TAC, and those approved will be forwarded to the HET for queue-scheduling (approximately 20% more proposals will be forwarded than can be scheduled to permit a deep queue).

The unique nature of the HET makes it absolutely essential that potential users of the HET become thoroughly familiar with its capabilities and restrictions. Descriptions of the salient features of the HET may be found in eleven papers in the March 1998 SPIE conferences at Kona, Hawaii. Researchers are especially urged to read Ramsey et al. (SPIE, 3352-06, 1998), Booth et al. (SPIE, 3351-20, 1998), and Gaffney & Cornell (SPIE, 3349-17, 1998). Potential PIs are also strongly urged to become familiar with the HET scheduling tools available on the Web at http://www.noao.edu/gateway/het/.

Among the most important differences between the HET and other NOAO telescopes are the following:

• HET is fully queue-scheduled using a Phase I, Phase II proposal process similar to that of the HST. Approved research programs resulting from Phase I proposals are required to complete a Phase II proposal prior to the commencement of observations. These proposals are described at http://www.noao.edu/gateway/het/.

• As a queue-scheduled telescope, there is no provision for the researcher to come to the HET. Data and calibrations acquired for a researcher are made available by ftp with notification to the researcher shortly after the observation is received at NOAO.

• The design of the HET permits observation only in a torus centered on the zenith. Time critical and synoptic observations must be considered very carefully with this observing constraint. The central circle of the torus is offset 35° from the zenith, permitting observations from approximately 71° to -10 ° declination (see Figure 8 of Ramsey et al. SPIE, 3352-06, 1998).

• Target tracking is accomplished with a prime focus tracker and is limited in duration to the time it takes the target to transit the torus (12°). This varies from about 0.75 hour at the southern declination limit to 2.5 hours at the northern limit.

• The HET has a roving pupil on the primary mirror. This changes the effective aperture (through a maximum of 9.2 m) over the course of an integration.

Investigators will be able to request telescope time on any or all nighttime facilities available through NOAO, including the HET, in a single proposal. Because the HET is queue-scheduled, approved community access programs will be entered into the queue rapidly upon receipt from NOAO of the completed Phase II proposal. Procedures and forms for applying for telescope time will be available on the Web at http://www.noao.edu/noaoprop/noaoprop.html after 1 February 2000. More detailed information about HET access can be found on the Web at http://www.noao.edu/gateway/het/.