Vanderbilt astronomers getting into planet-finding game

NASHVILLE, Tenn. Vanderbilt astronomers have constructed a special-purpose
telescope that will allow them to participate in one of the
hottest areas in astronomy the hunt for earthlike planets circling other
stars.

The instrument, called the Kilodegree Extremely Little Telescope
(KELT), has been assembled and is being tested at Vanderbilt's Dyer
Observatory. Shortly, it will be shipped to South Africa where it will
become only the second dedicated planet-finder scanning the stars in the
southern sky.

The KELT project is a collaboration between Vanderbilt and the
University of Cape Town. The instrument will be set up at the South African
Astronomical Observatory located about 200 miles northeast of the city of
Cape Town. The South Africans have built a special enclosure to hold the
telescope. They will maintain the instrument and ship the data that it
produces back to Nashville. The telescope is designed for remote operation
so it can be controlled by astronomers at both universities.

As its name implies, KELT is a very small telescope, about the
size of some of the telescopes used by amateur astronomers. Its optics are
surprisingly modest: It uses a professional quality photographic lens. But
it has an extremely high quality imaging system that captures the light and
converts it to digital data. It cost about $50,000 to construct.

"The telescope has been designed to detect planets passing
across the face of bright stars,"says Joshua Pepper, the post-doctoral
fellow who is managing the project. As a doctoral student at Ohio State
University, he worked on the problem of finding planets around distant stars
using large amounts of data. If a planet crosses the face of the star, it
blocks a small percentage of the sunlight. KELT is designed to detect these
subtle fluctuations in nearby stars similar to the sun. It is a copy of a
similar instrument that Pepper helped design for OSU that has been set up in
Arizona.

Unlike large telescopes that focus in on small parts of the sky
in order to produce extremely high resolution images, KELT looks at large
areas of the sky that contain thousands of stars. In order to see variations
in brightness, it must frequently revisit each area many times every night.
As a result, the small scope will produce prodigious amounts of data (enough
to fill a typical laptop' hard drive in a few days). In order to pick out
the variations caused by planets from other effects, such as dimming caused
by passing clouds or variations in a star' overall brightness, the
astronomers will process the data with the supercomputer in Vanderbilt's
Advanced Computing Center for Research & Education.

According to Associate Professor of Astronomy Keivan Stassun,
KELT is an example of a new program called the Vanderbilt Initiative in
Data-Intensive Astrophysics (VIDA) [http://www.vanderbilt.edu/astro/vida].
"Astronomy is now entering a period when the way astronomers do their work
is fundamentally changing," Stassun says. "The traditional model has been
that of an individual astronomer, or a small team of astronomers, going to a
telescope and pointing it at a star or a galaxy, collecting data, analyzing
the data and publishing the results. But, with the advent of
high-performance computers, robotic telescopes and digital detectors that
are able to see large swaths of the sky at once, the quantities of data that
we can collect are rapidly increasing so we need new ways of analyzing them
in real time." The purpose of VIDA, which is funded by the Office of the
Provost, is to give Vanderbilt astronomers the resources they need to become
leaders in this new way of conducting astronomical research.

The agreement to place the new telescope in South Africa was the
result of a second campus initiative coming from the Vanderbilt
International Office. "We are in the process of identifying peer
institutions in all parts of the world with whom we can collaborate on
research projects in a variety of disciplines," explains Joel Harrington,
assistant provost for international affairs.

The Cape Town agreement is one of four "International core
partnerships" that Vanderbilt has established. The other three are with the
University of Melbourne in Australia, The University in Sao Paulo in Brazil
and Fudan University in Shanghai, China.

In addition to collaborating on research projects, the
partnerships involve the exchange of students. Two Nashville students have
gone to Cape Town to study and two Cape Town students will come to
Nashville. A number of the Nashville exchange students will be drawn from
the Fisk-Vanderbilt Masters-to-PhD Program, a joint program with Fisk
University, Nashville's historically black university.

"An important goal of the new research partnership is building
and enhancing the scientific capacity among black South Africans and African
Americans," according to a media statement issued by the University of Cape
Town.

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on the Internet at www.vanderbilt.edu/News.