50 pc of all Exoplanet's host stars may actually be Binaries

Researchers have recently suggested that half of all Exoplanet's host stars are actually Binary stars.

A team of astronomers, led by Dr. Elliott Horch, Southern Connecticut State University, have shown that stars with exoplanets are just as likely to have a binary companion; that is, 40 percent to 50 percent of the host stars are actually binary stars.

The NASA Kepler Space Telescope has confirmed about 1000 exoplanets, as well as thousands more stars considered "Kepler objects of interest", dubbed KOIs, stars that could possibly host planets.

Binary stars have long been known to be commonplace; about half the stars in the sky are believed to consist of two stars orbiting each other.

The study used very high spatial resolution observations that were carried out on the WIYN telescope located on Kitt Peak in southern Arizona and the Gemini North telescope located on Mauna Kea in Hawaii.

The team used the technique called speckle imaging and consists of obtaining digital images of a small portion of the sky surrounding a star of interest, 15 to 25 times a second.

Dr. Steve B. Howell (NASA Ames Research Center), said that the findings are interesting, however, they cannot, in general, say which star in the system the planet actually orbits.

Kepler has discovered a number of circumbinary planets, a planet that orbits both stars in very close binary systems. There also exist exoplanets that are known to orbit one of the stars in very wide binary systems.

The study is published in the Astrophysical Journal.