Astronomers Must Compete for Telescope Time
by Richard Wainscoat
Over 90 IfA astronomers and graduate students are among those competing
for the UH's 10-15 percent of the observing time on Mauna Kea
telescopes. Photo by Richard Wainscoat.
There is a limited amount of observing time on the big telescopes on Mauna
Kea, and astronomers compete strongly for it. UH astronomers have access
to between 10 and 15 percent of the observing time on each of the Mauna
Kea telescopes. For all telescopes except the NASA Infrared Telescope Facility,
the IfA director allocates the UH observing time based on the recommendations
of the UH Time Allocation Committee (TAC). Since the IRTF is a national
telescope, it has its own TAC that includes scientists from throughout
the United States.
Most Mauna Kea telescopes are scheduled using common six-month semesters:
February-July and August-January. Twice each year (with deadlines on April
1 and October 1), UH scientists—including astronomers at IfA and
UH Hilo, and planetary geoscientists at the Hawaii Institute of Geophysics
and Planetology—write comprehensive research proposals detailing
all the observing time they are requesting during the upcoming semester.
Astronomers prioritize their proposed research projects to assist the TAC's
decision because the total time requested by UH scientists often far exceeds
The TAC is composed of nine UH faculty members, one postdoctoral research
fellow, and one graduate student. Most members of the committee are active
observational astronomers who regularly use the telescopes on Mauna Kea.
Their areas of expertise span a broad range of nighttime astronomy, including
the solar system, stars, star formation, extragalactic astronomy, and cosmology.
At present, two of the TAC members are located in Hilo. One is a UH Hilo
faculty member, and the other is an IfA faculty member located in Hilo.
The Hilo committee members sometimes fly to Honolulu for meetings, but
recently they have found it more convenient to attend via video-conferencing
The TAC must recommend how best to use our precious observing time. This
task is often formidable, with the requests for observing time far exceeding
what is available. Competition for observing time in the months of March
and April, when the North Galactic Pole is high in the sky, is particularly
For a typical semester, between 50 and 60 proposals will be submitted.
Each proposal comprises a scientific justification of up to five pages
of text, up to two pages of illustrations, and at least five pages of additional
information. Each committee member reads all of these proposals—a
daunting task—and ranks them. About three weeks after the proposal deadline, the committee members meet for an often
long (and usually exhausting) meeting, during which each proposal is thoroughly
discussed. The meeting typically lasts two to three full days. The committee
produces a prioritized list of recommended proposals for each telescope
and forwards this to the IfA director. The approved programs are then forwarded
to the directors of the respective telescopes for scheduling.
For classically scheduled observing, in which each project is assigned
one or more specific nights, astronomers remain at the mercy of the weather.
Poor luck with the weather can set back an observing program by a year.
However, high-ranked programs on queue-scheduled telescopes, which include
the Gemini North Telescope and the Canada-France-Hawaii Telescope, have
a high likelihood of being completed, independent of the weather. This
is because in queued observing, a list of objects to be observed is submitted
for each project, and these objects are observed in order of priority by
astronomers who work for that observatory. The data they collect is then
sent to the project astronomers. Space observatories such as the Hubble
Space Telescope also work in this manner.
The current observing schedule for the UH 2.2-meter (88-inch)
telescope shows who is observing and what instruments they are using. It
also lists IfA observers and equipment on other Mauna Kea telescopes.