Orbits and masses in the multiple system LHS 1070

We present a study of the orbits of the triple system LHS 1070, with the aim to determine individual masses of its components.<i>Methods.<i/> Sixteen new relative astrometric positions of the three components in the K band were obtained with NACO at the VLT, Omega CASS at the 3.5 m teles...

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Bibliographic Details
Main Authors: Köhler, Rainer (Author) , Ratzka, Thorsten (Author) , Leinert, Christoph (Author)
Format: Article (Journal)
Language:English
Published: 24 April 2012
In: Astronomy and astrophysics
Year: 2012, Volume: 541, Pages: 1-9
ISSN:1432-0746
DOI:10.1051/0004-6361/201118707
Online Access:Verlag, Volltext: http://dx.doi.org/10.1051/0004-6361/201118707
Verlag, Volltext: https://www.aanda.org/articles/aa/abs/2012/05/aa18707-11/aa18707-11.html
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Author Notes:R. Köhler, T. Ratzka and Ch. Leinert
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Summary:We present a study of the orbits of the triple system LHS 1070, with the aim to determine individual masses of its components.<i>Methods.<i/> Sixteen new relative astrometric positions of the three components in the K band were obtained with NACO at the VLT, Omega CASS at the 3.5 m telescope on Calar Alto, and other high-spatial-resolution instruments. We combined them with data from the literature and fit orbit models to the dataset. We derived an improved fit for the orbit of LHS 1070 B and C around each other, and an estimate for the orbit of B and C around A.<i>Results.<i/> The orbits are nearly coplanar, with a misalignment angle of less than 10°. The masses of the three components are <i>M<i/><sub><i>A<i/><sub/> = 0.13<i>...<i/>0.16 <i>M<i/><sub>⊙<sub/>, <i>M<i/><sub><i>B<i/><sub/> = 0.077 ± 0.005 <i>M<i/><sub>⊙<sub/>, and <i>M<i/><sub><i>C<i/><sub/> = 0.071 ± 0.004 <i>M<i/><sub>⊙<sub/>. Therefore, LHS 1070 C is certainly, and LHS 1070 B probably a brown dwarf. Comparison with theoretical isochrones shows that LHS 1070 A is either fainter or more massive than expected. One possible explanation would be that it is a binary. However, the close companion reported previously could not be confirmed.
Item Description:Gesehen am 07.11.2018
Physical Description:Online Resource
ISSN:1432-0746
DOI:10.1051/0004-6361/201118707