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Haleakala telescope finds planet

University of Hawaiʻi
Dr. James Heasley, (808) 956-6826
UH Institute for Astronomy
Karen Rehbock, (808) 956-6829
UH Institute for Astronomy
Posted: May 18, 2006

An international team of astronomers has used a small, automated telescope located on Haleakala to discover a planet orbiting a Sun-like star 600 light-years from Earth.

The team, led by Peter McCullough of the Space Telescope Science Institute in Baltimore, includes UH astronomer James Heasley. They used a relatively inexpensive telescope made from off-the-shelf components to scan the skies for extrasolar planets. Called the XO telescope, it consists of two 200-millimeter telephoto camera lenses and looks like a pair of binoculars.

The team found the planet, dubbed XO-1b, by noticing two percent dips in the star's light output when the planet passed in front of the star. The observation also revealed that XO-1b is in a tight four-day orbit around its parent star, which is in the constellation Corona Borealis.

Heasley stated, "In the future, we can use small telescopes such as XO to find out where planets around stars may be, and larger telescopes such as those on Mauna Kea to confirm such discoveries." The team confirmed XO-1b's existence by using the Harlan J. Smith Telescope and the Hobby-Eberly Telescope at the University of Texas's McDonald Observatory to measure the slight wobble induced by the planet on its parent star. This so-called radial-velocity method allowed the team to calculate a precise mass for the planet, which is slightly less than that of Jupiter (about 0.9 Jupiter masses).

University of Hawaii staff members on Maui who made operation of the XO telescope possible include Bill Giebink, Les Hieda, Jake Kamibayashi, Daniel O‘Gara, and Joey Perreira.

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The Institute for Astronomy at the University of Hawaii conducts research into galaxies, cosmology, stars, planets, and the sun. Its faculty and staff are also involved in astronomy education, deep space missions, and in the development and management of the observatories on Haleakala and Mauna Kea.

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