From: LARRY KLAES (ljk4_at_msn.com)
Date: Sun Oct 14 2007 - 17:19:13 PDT
Discovery of 18 Jupiter mass RV companion orbiting the brown dwarf candidate
ChaHa8
Authors: Viki Joergens, Andre Mueller
(Submitted on 12 Oct 2007)
Abstract: We report the discovery of a 16-20 Jupiter mass radial velocity
companion around the very young (3 Myr) brown dwarf candidate ChaHa8. Based
on high-resolution echelle spectra of ChaHa8 taken between 2000 and 2007
with UVES at the VLT, a companion was detected through RV variability with a
semi-amplitude of 1.6 km/s. A Kepler fit to the data yields an orbital
period of the companion of 1590 days and an eccentricity of e=0.49. A
companion minimum mass M2sin i between 16 and 20 Jupiter masses is derived
when using model-dependent mass estimates for the primary. The mass ratio
M2/M1 might be as small as 0.2 and, with a probability of 87%, it is less
than 0.4. ChaHa8 harbors most certainly the lowest mass companion detected
so far in a close (~1 AU) orbit around a brown dwarf or very low-mass star.
>From the uncertainty in the orbit solution, it cannot completely be ruled
out that the companion has a mass in the planetary regime. Its discovery is
in any case an important step towards RV planet detections around BDs.
Further, ChaHa8 is the fourth known spectroscopic brown dwarf or very
low-mass binary system with an RV orbit solution and the second known very
young one.
Comments: Proceeding of conference 'Extreme Solar Systems' held on
Santorini in June 2007, 4 pages, 1 figure
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0710.2437v1 [astro-ph]
Submission history
From: Viki Joergens [view email]
[v1] Fri, 12 Oct 2007 11:37:17 GMT (25kb)
http://arxiv.org/abs/0710.2437
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