A lucky imaging multiplicity study of exoplanet host stars
Version of Record online: 20 FEB 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society
Volume 421, Issue 3, pages 2498–2509, April 2012
How to Cite
Ginski, C., Mugrauer, M., Seeliger, M. and Eisenbeiss, T. (2012), A lucky imaging multiplicity study of exoplanet host stars. Monthly Notices of the Royal Astronomical Society, 421: 2498–2509. doi: 10.1111/j.1365-2966.2012.20485.x
- Issue online: 4 APR 2012
- Version of Record online: 20 FEB 2012
- Accepted 2012 January 2. Received 2012 January 2; in original form 2011 September 15
- techniques: high angular resolution;
- binaries: close;
- stars: individual: HD 126614;
- stars: individual: HD 185269
To understand the influence of additional wide stellar companions on planet formation, it is necessary to determine the fraction of multiple stellar systems amongst the known extrasolar planet population.
We target recently discovered radial velocity exoplanetary systems observable from the Northern hemisphere and with sufficiently high proper motion to detect stellar companions via direct imaging. We utilize the Calar Alto 2.2-m telescope in combination with its lucky imaging camera AstraLux.
71 planet host stars have been observed so far, yielding one new low-mass (0.239 ± 0.022 M⊙) stellar companion, 4.5 arcsec (227 au of projected separation) north-east of the planet host star HD 185269, detected via astrometry with AstraLux. We also present follow-up astrometry on three previously discovered stellar companions, showing for the first time common proper motion of the 0.5-arcsec companion to HD 126614. Additionally, we determined the achieved detection limits for all targets, which allow us to characterize the detection space of possible further companions of these stars.