ScienceDaily (Mar. 9, 2005) — An international team of astronomers have accurately determined the radius and mass of the smallest core-burning star known until now.

The observations were performed in March 2004 with the FLAMES multi-fibre spectrograph on the 8.2-m VLT Kueyen telescope at the ESO Paranal Observatory (Chile). They are part of a large programme aimed at measuring accurate radial velocities for sixty stars for which a temporary brightness "dip" has been detected during the OGLE survey.

The astronomers find that the dip seen in the light curve of the star known as OGLE-TR-122 is caused by a very small stellar companion, eclipsing this solar-like star once every 7.3 days.

This companion is 96 times heavier than planet Jupiter but only 16% larger. It is the first time that direct observations demonstrate that stars less massive than 1/10th of the solar mass are of nearly the same size as giant planets. This fact will obviously have to be taken into account during the current search for transiting exoplanets.

In addition, the observations with the Very Large Telescope have led to the discovery of seven new eclipsing binaries, that harbour stars with masses below one-third the mass of the Sun, a real bonanza for the astronomers.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by European Southern Observatory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

This is a comparison between the newly found low-mass star OGLE-TR-122b and the Sun and Jupiter. OGLE-TR-122b, while still 96 times as massive as Jupiter, is only 16% larger than this giant planet. It weighs 1/11th the mass of the Sun and has 1/8th of its diameter. (credits: Sun image: SOHO/ESA; Jupiter: Cassini/NASA/JPL/University of Arizona/ESA)

Related Stories

Astronomers Take a Look Inside Red Giant Stars (Mar. 31, 2011) — Astronomers have used data from NASA's Kepler spacecraft to see into the core of red giant stars. The scientists said the discovery will help astronomers learn more about red giants. Our sun will ...  > read more

Exoplanet Orbiting Sun-Like Star Discovered (July 25, 2008) — Astronomers have discovered an exoplanet orbiting a star slightly more massive than the Sun. After just 555 days in orbit, the COROT mission has now observed more than 50 000 stars and is adding ...  > read more

First Habitable-Zone Super-Earth Discovered in Orbit Around a Sun-Like Star (Dec. 5, 2011) — NASA's Kepler Mission has discovered the first super-Earth orbiting in the habitable zone of a star similar to the Sun. A team of researchers, including Carnegie's Alan Boss, has discovered what ...  > read more

Jet Of Molecular Hydrogen Arising From A Forming High-Mass Star (Mar. 7, 2007) — A team of European astronomers offer new evidence that high-mass stars could form in a similar way to low-mass stars, that is, from accretion of gas and dust through a disk surrounding the forming ...  > read more

Search ScienceDaily