Issue |
A&A
Volume 424, Number 2, September III 2004
|
|
---|---|---|
Page(s) | 619 - 625 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361:20040016 | |
Published online | 23 August 2004 |
X-ray detections of two young bona-fide brown dwarfs*
Max Planck für Extraterrestrische Phyisk, Giessenbachstraße, 85748 Garching bei München, Germany e-mail: hbouy@mpe.mpg.de Laboratoire d'Astrophysique de l'Observatoire de Grenoble, 414 rue de la piscine, 38400 Saint Martin d'Hères, France European Southern Observatory, Karl Schwarzschildtstraße 2, 85748 Garching bei München, Germany
Received:
6
January
2004
Accepted:
17
April
2004
I report the detection of two bona-fide brown dwarfs by XMM-Newton: [GY92] 141 in the ρ -Ophiuchus star-forming region and DENIS J155601-233809 in the Upper Scorpius OB association. The two objects have been detected with luminosities of erg s-1 and
erg s-1 respectively, corresponding to luminosity ratios of
log (
and log (
. The two sources were close to the limit of detection of the instruments at only 2~3-σ above the background level, and no significant flare or variation could be detected during the 48.3 ks and 33.9 ks observations. [GY92] 141 had already been observed 10 months earlier with Chandra by [CITE] with a luminosity ~14 times fainter than the one reported here, indicating that the X-ray emission of this object is strongly variable.
Key words: stars: low-mass, brown dwarfs / stars: coronae / X-rays: individuals: [GY92] 141, DENIS J155601-233809
© ESO, 2004
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