Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2B060

Radial velocity variations in EX Lup: hints for a low-mass close companion

Kóspál, Ágnes (European Space Agency)
Mohler-Fischer, Maren (Max-Planck-Institut für Astronomie)
Sicilia-Aguilar, Aurora (Universidad Autonóma de Madrid)
Ábrahám, Péter (Konkoly Observatory)
Curé, Michel (Universidad de Valparaíso)
Henning, Thomas (Max-Planck-Institut für Astronomie)
Kiss, Csaba (Konkoly Observatory)
Launhardt, Ralf (Max-Planck-Institut für Astronomie)
Moór, Attila (Konkoly Observatory)
Müller, André (European Southern Observatory)

EXors are low-mass pre-main sequence objects producing repetitive optical outbursts attributed to highly enhanced accretion from the circumstellar disk onto the star. One type of outburst theories requires a close stellar or sub-stellar companion that perturbs the inner part of the disk and triggers the onset of the enhanced accretion. Here, we look for a possible companion to EX Lup, the prototype of the EXor class, using radial velocity (RV) observations. The RVs show large periodic variations that can be explained by the presence of a close companion in the brown dwarf mass range. Chromospheric activity or starspots are less likely to explain the observed RV curve.

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