November 13, 2012
A New Set Of Directions For Exoplanet Hunting
Lawrence LeBlond for redOrbit.com - Your Universe Online
The search for planets around other stars might have gotten a little easier now that a Lowell Observatory astronomer and her colleagues have developed a set of directions, per se, to aid others in the hunt for exoplanets.
Publishing their work in the journal Astrophysical Letters, Evgenya Shkolnik and her collaborators examined new and existing data from known stars and brown dwarfs that are less than 300 million years old, as determined from strong X-ray emission readings. The team identified more than 140 young targets for exoplanet searches, with no less than 20 very strong candidates.
Involved in this exoplanetary search are Institute of Astronomy, University of Hawaii astronomer Michael Liu and graduate student Brendan Bowler. Both collaborators have been using Gemini´s NICI Planet-Finding Campaign and the Planets Around Low-Mass Stars survey to search out candidate planets.
Shkolnik and her team carefully examined the age of the stars they tracked down using spectroscopic data and measuring the motions of stars. Since low-mass stars are small and dim, they make ideal candidates for directly imaging any potential planets around them. And young stars make the process even easier since young planets would still be hot and bright. The team added that knowing the age of the system allows for characterizations of the planet itself beyond initial detection.
Getting their list of candidates was no easy task–they had to sift through data of nearly 8,700 stars within 100 light years of our Sun. The spectra were collected using the Keck Telescope and the Canada-France-Hawaii Telescope, both located on Mauna Kea in Hawaii. Star Distances were measured by Guillem Anglada-Escude (UniversitÃ¤t GÃ¶ttingen) using the du Pont telescope in Chile, operated by the Carnegie Institution for Science.
Bowler said in a statement that “low-mass stars are the most common type of star in our galaxy,” and these environments are the most likely place to find planets. “Finding young versions of these stars to search for planets is fundamental to understanding the galactic census of exoplanets.”
“These young stars help point the way. And if the Jupiter-mass planets are there, we will find them,” added Dr. Shkolnik.