Time-domain observations will serve as the backbone for 21st century astrophysics. Wide-field imaging at all wavelengths demonstrates that the universe is highly dynamic, with variability on all time-scales. Of great interest are exploding stars, black hole mergers, eclipsing planets, gravitational microlensing events, and flaring sources, which stem from a diverse set of astrophysical processes. Central to resolving the astrophysics of these events is high-precision spectroscopy and imaging, ideally at critical times and/or high cadence. Such observations demand the use of large-aperture telescopes; but while a telescope may possess a suite of suitable instrumentation, the scientific returns of time-domain astrophysics are only available if those instruments can be flexibly and rapidly accessed on each observing night. Indeed, the growing demands for precious follow-up time using the world?s largest telescopes conflicts with the classical approach of telescope allocation: one night, one instrument.
Dr. Jason Prochaska of the University of California, Santa Cruz seeks to remedy this situation for the 10-m diameter optical/infrared Keck I telescope at the W. M. Keck Observatory atop Mauna Kea by replacing the manually positioned tertiary mirror with a remotely-articulated mirror capable of rapid (~2 minutes) switchover among the instruments that reside on the Cass focus and either of the two Nasmyth foci. When coupled with a planned change in telescope scheduling, this technologically straightforward modification will not only enable prompt response to astronomical events (e.g., supernova eruptions, gamma-ray bursts, planetary impacts), but also more easily permit cadence observing, address limited-access targets, and select the instrument and observing program which make best use of a particular night?s weather conditions. These developments will further enhance the capabilities of what is by virtually any measure one of the most productive and significant facilities available to modern-day astronomers, and allow it to continue to play a major role in understanding the time-variable universe.
Funding for development and construction of the prototype spectrograph is being provided by NSF's Division of Astronomical Sciences through its participation in the Major Research Instrumentation program.
