The 2.7-m (107-inch) Harlan J. Smith Telescope, is the largest telescope on Mt Locke. The University of Texas at Austin operates the facility through the support of the state of Texas and offers time at no cost to users. Four instruments are currently available for use on the telescope, though only one instrument can be mounted at a time. The instruments are scheduled for use in blocks based on proposal selection and science scheduling constraints.

Remote observing is available at this facility for UT Austin prospers only. Classical observing is available to other proposers, please note that UT Austin proposals are prioritized over others.

Other Links

Observer schedules: https://mcdonald.utexas.edu/for-researchers/observer-tools/observing-schedules

Proposals: https://mcdonald.utexas.edu/for-researchers/observer-tools/telescope-scheduling-policies-procedures

Important Updates

Telescope Information

Primary Mirror
Diameter	2.72 m (107")	Focal Length	10.68 m (35')	F-ratio	3.93
Cassegrain f/8.8 (Ritchey-Chretien) focus
Focal length	23.91 m (78.4')	F-ratio	8.8
Field of view	61.5 arcmin	Plate scale	8.62 arctic/mm
Cassegrain f/17.7 focus
Focal length	47.98 m (157.4')	F-ratio	17.65
Field of view	31 arcmin	Plate Scale	4.29 arcsec/mm
Coudé f/32.5 focus
Focal length	88.43 m (290.1')	F-ratio	32.54
Field of view	6 arcmin	Plate scale	2.32 arcsec/mm

Instrument Resources

Operational Resources

Publication Credits

Documenting the published scientific output of our facilities is an important part of our reporting duties and essential for our understanding of our productivity as a facility. Therefore, authors who publish papers wholly or partially based on data collected at the HJST are required to credit the use of the telescope with the following acknowledgement: "Based on observations made with the Harlan J. Smith Telescope, owned by the University of Texas at Austin at the McDonald Observatory, Texas"

Public Access

As part of the daily guided tours offered by the Observatory’s Visitors Center, a guide will escort visitors onto the dome floor for roughly 45 minutes starting at, approximately, 12:30 p.m. and again occasionally at 2:30 p.m. Tours vary in size throughout the year. They average around 35 people. School groups may also visit the telescope during the day at various times and are generally the same size as guided tours and receive similar treatment.

As part of the tour experience, the guides (all trained Observatory personnel) have permission to: operate the platform floors, move the telescope in both axes, rotate the dome, open the dome for very brief periods (providing conditions allow), and turn off the dome AC for the duration of the tour.

In the event of work being conducted on the telescope at the time of the tour, guides have been instructed to perform only those demonstrations for which they are given specific permission at the time. Guides have also been instructed to abide by the "Do Not Move" sign when placed in front of the control panel even in the event that no one appears to be working on the telescope at the time.

If your observing project would be hindered by any of these demonstrations, please alert our Observing Support Staff (mcd-os@utlists.utexas.edu) with instructions as to which demonstrations you would prefer they not conduct.

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