Vanderbilt astronomers getting into planet-finding game

The instrument, called the Kilodegree Extremely Little Telescope (KELT), has been assembled and is being tested at Vanderbilt¹s 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.

³The telescope has been designed to detect planets passing across the face of bright stars,² 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 laptop¹s 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 star¹s overall brightness, the astronomers will process the data with the supercomputer in Vanderbilt¹s 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].

³Astronomy is now entering a period when the way astronomers do their work is fundamentally changing,² Stassun says. ³The 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.² 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. ³We 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,² explains Joel Harrington, assistant provost for international affairs.

The Cape Town agreement is one of four ³international core partnerships² that Vanderbilt has established. The other three are with the University of Melbourne in Australia, The University in São 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 Master¹s-to-PhD Program, a joint program with Fisk University, Nashville¹s historically black university.

³An important goal of the new research partnershipŠis building and enhancing the scientific capacity among black South Africans and African Americans,² according to a media statement issued by the University of Cape Town.

Vanderbilt University is a private research university of approximately 6,500 undergraduates and 5,300 graduate and professional students. Founded in 1873, the University comprises 10 schools, a public policy institute, a distinguished medical center and The Freedom Forum First Amendment Center.

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