Japanese astronomers now have access to a powerful spectograph on Keck, and astronomers who use Keck now have access to Subaru's unique Suprime-Cam imaging camera. Keck and Gemini have also made a time sharing agreement.

Four of the world's nine largest telescopes are on Mauna Kea: two Keck telescopes, the Gemini North telescope and Subaru. Each telescope has its characteristic strengths, but each telescope also serves a distinct community of astronomers, usually from the country or institutions that funded the telescope.

Time exchange between telescopes on Mauna Kea promise a new era of close collaboration between observatories on Mauna Kea to maximize the scientific potential of some of the most powerful telescopes in the world and produce ever more exiting discoveries about our Universe.

Drs. Fred Chaffee, Matt Mountain and Hiroshi Karoji, directors of Keck, Gemini and Subaru, respectively, wrote a letter to the newspaper West Hawaii Today to share this exciting news with the people of Hawaii. The full text of the letter follows.

New Capabilities Inaugurate a New Era of Cooperation among the Keck, Gemini and Subaru Observatories

Frederic Chaffee, Matt Mountain and Hiroshi Karoji

Four of the world’s nine largest operational telescopes—the two Keck 10-m telescopes, and the Gemini 8.1-m and Subaru 8.2-m telescopes—reside atop Mauna Kea, making the entire astronomy complex there the most powerful in the world. We have recently taken steps to assure that this entire “system” of premier telescopes is used to maximum advantage by the world’s best astronomers.

Often viewed by non-astronomers as locked in fierce competition with each other, the reality of inter-observatory relationships is much different. Each serves a different community of astronomers. Keck observers come largely from the institutions who fund the observatory—the University of California, Caltech and NASA. Subaru serves the astronomers of Japan and Gemini those of the seven countries—the US, the UK, Canada, Australia, Brazil, Argentina and Chile—who make up the Gemini partnership. In addition, all three provide observing time to astronomers from the University of Hawaii.

With such a huge constituency of worldwide astronomers to serve, the demand for time on these large Mauna Kea telescopes exceeds the supply by a factor of from three to five. Many requests by the world’s best astronomers for observing time at Keck, Gemini and Subaru must be turned down because time is simply not available.

All of the major Mauna Kea telescopes have a suite of basic instruments which record the light from celestial sources for analysis by astronomers. The majority of instruments at any modern observatory are of two basic types—imagers and spectrographs. Imagers take “pictures” of the Universe—the magnificent pictures from the Hubble telescope are familiar to people all over the world; even more spectacular images are beginning to be produced by the Mauna Kea “giants.”

Spectrographs spread out the light from celestial sources into their component colors—providing the equivalent of a “fingerprint” or the “DNA signature” of celestial objects. It is through the study of spectra that astronomers learn most about the nature of the amazing constituents—planets, stars, galaxies, black holes, pulsars, gamma-ray bursters, and the like--of the Universe.

In their determination to provide the best possible facilities for the world’s astronomers Keck, Gemini and Subaru have collaborated informally for many years. Their Directors meet regularly to discuss common problems and concerns. Technical groups at each observatory meet regularly to exchange ideas and share technical insights. Experts from each observatory regularly serve on review and advisory committees for the other two. Equipment is often shared among observatories. We live in and observe the same universe.

Recent advances in astronomical instrumentation have spawned an even closer relationship. In recent months, Gemini has begun commissioning a new instrument named MICHELLE—an acronym meaning “mid-infrared echelle” spectrograph. It offers a unique capability available at none of the other large Mauna Kea telescopes. For example, astronomers can explore the dust in proto-planetary disks to find evidence of hidden planets or probe the dust produced by the very first stars in distant galaxies.

Keck itself has recently commissioned a unique new capability for one of its “workhorse” instruments—the High Resolution Echelle Spectrograph (HIRES). The new capability, many years in development, will greatly increase HIRES’ sensitivity to light of all colors, but especially to ultraviolet light to which it has hitherto been all but “blind.” In the past, HIRES has been the world leader in discovering planets around other stars—in the last 8 years some 70 new Jupiter-sized planets have been discovered by Keck’s “planet-hunter” team. However, planets smaller than Jupiter have so far eluded detection by HIRES. This newly-inaugurated capability should allow Neptune-sized planets—1/3 the mass of Jupiter--around other stars to be detected for the first time.

Recognizing that their respective observatories have developed unique capabilities that both of their user communities could exploit to produce new and exciting discoveries, the Directors of Keck and Gemini recently reached a formal agreement whereby Gemini astronomers will be given access to HIRES on Keck and Keck astronomers to MICHELLE on Gemini. This is the first formal time-exchange agreement between two Mauna Kea observatories.

In a parallel development, Subaru and Keck recently arranged to exchange time when it was realized that a program already assigned time at Keck could better be done using Subaru’s “Suprime-Cam,” and that Keck has a unique and powerful spectrograph—DEIMOS—for which no equivalent is available to Subaru astronomers. Thus a deal was struck whereby Subaru scientists observed with DEIMOS at Keck, and Keck scientists will carry out their research with Suprime-Cam at Subaru.

These first steps toward time exchange among Mauna Kea’s large observatories promise a new era of even closer collaboration, an era when we jointly seek to maximize the creative potential of all Mauna Kea astronomers, telescopes and instruments to produce ever more exciting discoveries about our rich and infinitely varied Universe.

Drs. Frederic H. Chaffee, Matt Mountain and Hiroshi Karoji are the Directors of the Keck, Gemini and Subaru Observatories, respectively.