Stellar companions to two exoplanet hosts

The multiplicity of exoplanet host stars - New low-mass stellar companions of the exoplanet host stars HD125612 and HD212301
http://arxiv.org/abs/0812.2561

Abstract wrote:

Aims: We present new results from our ongoing multiplicity study of exoplanet host stars, carried out with SofI/NTT. We provide the most recent list of confirmed binary and triple star systems that harbor exoplanets.
Methods: We use direct imaging to identify wide stellar and substellar companions as co-moving objects to the observed exoplanet host stars, whose masses and spectral types are determined with follow-up photometry and spectroscopy.
Results: We found two new co-moving companions of the exoplanet host stars HD125612 and HD212301. HD125612B is a wide M4 dwarf (0.18 Msun) companion of the exoplanet host star HD125612, located about 1.5 arcmin (~4750 AU of projected separation) south-east of its primary. In contrast, HD212301B is a close M3 dwarf (0.35 Msun), which is found about 4.4 arcsec (~230 AU of projected separation) north-west of its primary.
Conclusions: The binaries HD125612AB and HD212301AB are new members in the continuously growing list of exoplanet host star systems of which 43 are presently known. Hence, the multiplicity rate of exoplanet host stars is about 17%.
Based on observations obtained on La Silla in ESO programs 079.C-0099(A), 080.C-0312(A)

This paper, at the very end, makes a very nifty listing of all exopanet host binary star systems, followed by an equally spiffy exoplanet tripple star systems list. In the binary star system list, HD 101903 is mentioned. I'm unsure why this star is amongst them, as it isn't known to host any planets.

Sirius_Alpha wrote:

This paper, at the very end, makes a very nifty listing of all exopanet host binary star systems, followed by an equally spiffy exoplanet tripple star systems list. In the binary star system list, HD 101903 is mentioned. I'm unsure why this star is amongst them, as it isn't known to host any planets.

The reference is to a paper which includes the discovery of a stellar companion around HD 101930. Typo.

Now introducing: TrES-2, TrES-4, and WASP-2, as binary stars.
http://arxiv.org/abs/0902.2179

As these stars are now known to be binary, the radius of the planets they possess is slightly larger than thought. Starlight from the secondary source was probably mixed in with photometry data which was used to determine the planet's radius.