Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123

Details Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123 Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123

Mar 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006a%26a...447.1035p&link_type=abstract

Astronomy and Astrophysics, Volume 447, Issue 3, March I 2006, pp.1035-1039

Astronomy and Astrophysics

Astrophysics

20

Binaries: Eclipsing, Stars: Low-Mass, Brown Dwarfs

Scientific paper

The system OGLE-TR-123, detected by the OGLE planetary transit survey in Carina, was shown by subsequent spectroscopic follow-up to be an eclipsing binary with a very low mass companion (M2 ˜ 0.07 M_&sun;). Neither the light curve nor the radial velocity data were sufficient to constrain the parameters more precisely and to exclude alternative explanations in terms of a triple system. In this paper, new HARPS radial velocity data and a precise photometric monitoring of the transit with VLT/FORS2 are presented, resulting in an improved mass and radius determination for OGLE-TR-123b and the rejection of alternative scenarios. We find M_2=0.085 ± 0.011~M_&sun; and R_2=0.133± 0.009 R_&sun; for the transiting companion, confirming its nature as a small M dwarf near the hydrogen-burning limit. Its mass-radius relation corresponds to expectations for a relatively young object. The primary is an F dwarf that does not rotate synchronously with the orbital motion. Asynchronous rotation is unexpected in such a close binary (P=1.8 days) but could be explained by the small mass of the secondary, the young age for the system, and the absence of convective envelope in the primary. OGLE-TR-123b is one of only two known objects below 0.1 M_&sun; with directly determined radii, after a similar object was characterised around OGLE-TR-122. The characterisation of OGLE-TR-123 provides another example of the type of system that can closely mimic planetary transits and contaminate transit surveys.

Affiliated with

Also associated with

No associations

Rating

Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1579004