Planetary-mass companions to a retired B star BD+37 3172 and a retired F star BD+42 2315

Abstract

Radial velocity searches may lead to detection of exoplanets at large orbital separations only if long-enough time-series of data are available. Therefore publication of precise measurements collected in the past is very valuable even if not successfully completed with a definitive detection. Here we present 309 precise ($\ddot{I}ƒ$RV$\approx$5-7 m s${}^{-1}$) multi-epoch radial velocities for 28 stars observed with the Hobby-Eberly Telescope and its High Resolution Spectrograph between 2004 and 2013. Based on the observations gathered we present a low mass companion ($m_p\sin i$ = 10.6 $M_J$ in 1887.76 $\pm$ 0.01 d, 4.65 au orbit with $e$ = 0.59 $\pm$ 0.01) to a K giant BD+37 3172 ($M$=3.75$\pm$ 0.86 M${}_{\odot }$), and a planetary mass companion (m${}_p\sin i$=0.55 M${}_J$ in 123.05$\pm$0.04 day, 0.55 au orbit with e=0.73$\pm$0.03) to a K giant BD+42 2315 ($M$=1.38$\pm$ 0.30 M${}_{\odot }$). We also present two preliminary detections of new spectroscopic binaries: BD+56 2957 (K5) and HD 236555 (G5).