* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: K giant exoplanet


L

Posts: 131433
Date:
K giant exoplanet
Permalink  
 


Title: Planetary companions in K giants beta Cancri, mu Leonis, and beta Ursae Minoris
Author: B.-C. Lee, I. Han, M.-G. Park, D. E. Mkrtichian, A. P. Hatzes, K.-M. Kim

Aims. The aim of our paper is to investigate the low-amplitude and long-period variations in evolved stars with a precise radial velocity (RV) survey.
Methods. The high-resolution, the fibre-fed Bohyunsan Observatory Echelle Spectrograph (BOES) was used from 2003 to 2013 for a radial velocity survey of giant stars as part of the exoplanet search program at Bohyunsan Optical Astronomy Observatory (BOAO).
Results. We report the detection of three new planetary companions orbiting the K giants beta Cnc, mu Leo, and beta UMi. The planetary nature of the radial velocity variations is supported by analysis of ancillary data. The HIPPARCOS photometry shows no variations with periods close to those in RV variations and there is no strong correlation between the bisector velocity span (BVS) and the radial velocities for each star. Furthermore, the stars show weak or no core reversal in Ca II H lines indicating that they are inactive stars. The companion to beta Cnc has a minimum mass of 7.8 M_Jup in a 605-day orbit with an eccentricity of 0.08. The giant mu Leo is orbited by a companion of minimum mass of 2.4 M_Jup having a period of 357 days and an eccentricity of 0.09. The giant beta UMi is a known barium star and is suspected of harboring a white dwarf or substellar mass companion. Its companion has a minimum mass of 6.1 M_Jup, a period of 522 days, and an eccentricity e = 0.19.

Read more (255kb, PDF)



__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard