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> Brown dwarf TWA-5B seen with the VLT

Brown dwarf TWA-5B seen with the VLT

author: ESO/Novapix

reference: a-eto03-00002

Image Size 300 DPI: 6 * 6 cm

An image of TWA-5 A (lower, bright object) and TWA-5 B (upper), taken with the FORS-2 multi-mode instrument at the 8.2-m VLT/KUEYEN telescope on 21 February 2000. The lines emerging from the bright image are caused by optical reflection in the telescope. Brown Dwarfs are smaller than normal stars, they shine by their own energy for a limited time, in contrast to planets. This small object is known as TWA-5 B and with a mass of only 15 - 40 times that of Jupiter, it is near the borderline between planets and Brown Dwarfs. However, visible and infrared VLT spectra unambiguously classify it in the latter category. Accurate positional measurements with the Hubble Space Telescope (HST) and the VLT hint that it is orbiting the central, much heavier and brighter star in this system, TWA-5 A (itself a close double star of which each component presumably has a mass of 0.75 solar masses), with a period that may be as long as 900 years.

Keywords for this photo:

2000 - ASTRONOMY - BROWN DWARF - DWARF - HYDRA - STAR - TW5-A - TW5-B - VERY LARGE TELESCOPE - VLT -