The mass-radius relationship for very low mass stars: four new discoveries from the HATSouth Survey

We report the discovery of four transiting F-M binary systems with companions between 0.1 and 0.2 M in mass by the HATSouth survey. These systems have been characterized via a global analysis of the HATSouth discovery data, combined with high-resolution radial velocities and accurate transit photome...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society 2014-01, Vol.437 (3), p.2831-2844
Main Authors: Zhou, G., Bayliss, D., Hartman, J. D., Bakos, G. Á., Penev, K., Csubry, Z., Tan, T. G., Jordán, A., Mancini, L., Rabus, M., Brahm, R., Espinoza, N., Mohler-Fischer, M., Ciceri, S., Suc, V., Csák, B., Henning, T., Schmidt, B.
Format: Article
Language:English
Subjects:
Astronomy
Star & galaxy formation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We report the discovery of four transiting F-M binary systems with companions between 0.1 and 0.2 M in mass by the HATSouth survey. These systems have been characterized via a global analysis of the HATSouth discovery data, combined with high-resolution radial velocities and accurate transit photometry observations. We determined the masses and radii of the component stars using a combination of two methods: isochrone fitting of spectroscopic primary star parameters and equating spectroscopic primary star rotation velocity with spin-orbit synchronization. These new very low mass companions are HATS550-016B ( , ), HATS551-019B ( , ), HATS551-021B ( , ) and HATS553-001B ( , ). We examine our sample in the context of the radius anomaly for fully convective low-mass stars. Combining our sample with the 13 other well-studied very low mass stars, we find a tentative 5 per cent systematic deviation between the measured radii and theoretical isochrone models.
ISSN:0035-8711
1365-2966
DOI:10.1093/mnras/stt2100