Computation of the Cost of a Night of Keck Telescope Observing

The cost of one night of observing with one of the Keck 10-meter telescopes is derived from two numbers; total annual cost of the Keck facility divided by the number of nights the telescopes are used for observations by the Keck Observatory partners.

Cost per night = (Annual cost) / (Number of nights telescopes used by partners)

The annual cost is a combination of three cost areas:

• Amortized telescope development
• Amortized instrument development
• Annual operations cost

The latest allocation of observing from Keck was proposed to begin in Semester 2012B, so the costs as presented in the most recent Keck proposal reflect the Keck 2012 budget and the costs of new capabilities for which funds have been committed through FY12:

• Telescope development costs are linearly amortized over 20 years.
• Instrumentation costs are linearly amortized over 10 years.
• The costs are in actual year dollars (no inflation factor used).
• The annual operation cost is the amount of funds provided annually by the Keck Observatory partners.
• The Keck Interferometer project is not included in the cost. The TSIP computation is for the two single apertures and associated instrumentation.

The total development cost for the Keck telescopes was $192.3 million, through FY12. The total development cost for the instruments is $78.2 million.

Keck I instrumentation: HIRES, LRIS red & blue, MOSFIRE (available Semester 2013A)

Keck II instrumentation: Adaptive Optics, DEIMOS, ESI, NIRC2, NIRSPEC, OSIRIS

The annual operations funds come from contributions by the University of California and NASA. In FY12, these funds are projected to be $14.8 million. Combining these figures, the total annual cost for FY12 is computed (figures are in millions of dollars).

The number of observing nights available to the Keck Observatory partners is the time remaining after subtraction of engineering time and U.Hawaii observing time. The expected allocation over the period of time anticipated for the most recent exchange is as shown in the table below.

With an annual cost of $30.8 million and 574 nights available for observing, the cost of one observing night on a Keck telescope is $53.7 thousand dollars.