Substellar-mass companions to the K-giants HD240237, BD +48 738, and HD96127

S. Gettel, A. Wolszczan, A. Niedzielski, G. Nowak, M. Adamów, P. Zieliński, G. MacIejewski

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Abstract

We present the discovery of substellar-mass companions to three giant stars by the ongoing Penn State-Toruń Planet Search conducted with the 9.2m Hobby-Eberly Telescope. The most massive of the three stars, K2-giant HD240237, has a 5.3 MJ minimum mass companion orbiting the star at a 746 day period. The K0-giant BD+48738 is orbited by a ≥0.91 MJ planet which has a period of 393 days and shows a nonlinear, long-term radial velocity (RV) trend that indicates a presence of another, more distant companion, which may have a substellar mass or be a low-mass star. The K2-giant HD96127 has a ≥4.0 MJ mass companion in a 647 day orbit around the star. The two K2-giants exhibit a significant RV noise that complicates the detection of low-amplitude, periodic variations in the data. If the noise component of the observed RV variations is due to solar-type oscillations, we show, using all the published data for the substellar companions to giants, that its amplitude is anti-correlated with stellar metallicity.

Original languageEnglish (US)
Article number28
JournalAstrophysical Journal
Volume745
Issue number1
DOIs
StatePublished - Jan 20 2012

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All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Gettel, S., Wolszczan, A., Niedzielski, A., Nowak, G., Adamów, M., Zieliński, P., & MacIejewski, G. (2012). Substellar-mass companions to the K-giants HD240237, BD +48 738, and HD96127. Astrophysical Journal, 745(1), [28]. https://doi.org/10.1088/0004-637X/745/1/28