Search for Exoplanets around Northern Circumpolar Stars V. Three likely planetary companions to the giant stars HD 19615, HD 150010, and HD 174205

TL;DR

This paper reports the discovery of three long-period planetary companions orbiting giant stars, identified through precise radial velocity measurements, contributing valuable data on planets around intermediate-mass stars.

Contribution

First detection of planetary companions around three giant stars via RV measurements in the SENS survey, expanding knowledge of planets around intermediate-mass stars.

Findings

Orbital periods of 402, 562, and 582 days.

Minimum masses of 8.5, 2.4, and 4.2 Jupiter masses.

No variability in photometry or line shape correlating with RV signals.

Abstract

Aims. We report the detection of long-period radial velocity (RV) variations in three giant stars, HD 19615, HD 150010, and HD 174205, using precise RV measurements. Methods. These detections are part of the Search for Exoplanets around Northern Circumpolar Stars (SENS) survey being conducted at the Bohyunsan Optical Astronomy Observatory (BOAO). The nature of the RV variations was investigated by analyzing the photometric and line shape variations. We found no variability with the RV period in these quantities and conclude that the RV variations are most likely caused by planetary companions. Results. Orbital solutions for the three stars yield orbital periods of 402 d, 562 d, and 582 d and minimum masses of 8.5 MJ , 2.4 MJ , and 4.2 MJ , respectively. These masses and periods are typical for planets around intermediate-mass stars, although some unclear interpretations and recent studies may being calling some planet convictions into question. Nevertheless, the SENS program is contributing to our knowledge of giant planets around intermediate-mass stars.