Brown Dwarf found in the vicinity of the Sun

A faint and lonely Brown Dwarf was discovered recently in the vicinity of the Sun by Maria Teresa Rui¥of the astronomy department at the Universidad de Chile (Santiago, Chile) while working at the European Southern Observatory (ESO) La Silla facility.

Brown Dwarf found in the vicinity of the Sun

Roland Roux

A faint and lonely Brown Dwarf was discovered recently in the vicinity of the Sun by Maria Teresa Rui¥of the astronomy department at the Universidad de Chile (Santiago, Chile) while working at the European Southern Observatory (ESO) La Silla facility.

Brown Dwarfs are star-like objects that are too small to become real stars but too large to be considered planets. Their mass is not enough to ignite the nuclear processes responsible for the high energy and temperatures associated with stars, but it is much larger than that of any of the known planets in our solar system.

It has been suggested that Brown Dwarfs may constitute a substantial part of the unseen dark matter in our galaxy. This discovery may, therefore, have important implications for those working in this area.

Earlier this year Rui¥was checking two similar photographic plates taken 11 years apart and discovered a very faint object in the southern constellation of Hydra (Water-Snake) moving at 0.35 arc sec per year. Further observations were made on March 15 in the visible and near-infrared spectral regions (between 450 and 1000 nm) using the ESO 3.6-m telescope and the EFOSC 1 spectrograph.

The new object is apparently quite near to us--about 10 par sec from the Sun--and is unaffected by other objects. Its visual magnitude is 22.3--that is, more than 3 million times fainter than can be seen with the unaided eye. The new object has been called KELU 1, and its discovery was confirmed in April by Sandra K. Leggett of the USA using the UK infrared telescope on Mauna Kea (Hawaii).

For the future, high-resolution spectral investigations with large telescope facilities such as the ESO`s Very Large Telescope at the Paranal observatory in northern Chile will enable investigation of the processes that take place in the relatively cold upper layers of Brown Dwarfs.

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