Tracking Advanced Planetary Systems (TAPAS) with HARPS-N^⋆,⋆⋆

IV. TYC 3667-1280-1: The most massive red giant star hosting a warm Jupiter

¹ Toruń Centre for Astronomy, Faculty of Physics, Astronomy and Applied Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Toruń, Poland
e-mail: Andrzej.Niedzielski@umk.pl
² Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco 28049 Madrid, Spain
e-mail: Eva.Villaver@uam.es
³ Instituto de Astrofísica de Canarias, 38205, La Laguna, Tenerife, Spain
⁴ Departamento de Astrofísica, Universidad de La Laguna, 38206, La Laguna, Tenerife, Spain
⁵ McDonald Observatory and Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1402, Austin, TX 78712-1206, USA
⁶ National Center for Supercomputing Applications, University of Illinois, Urbana-Champaign, 1205 W Clark St, MC-257, Urbana, IL 61801, USA
⁷ Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802, USA
e-mail: alex@astro.psu.edu
⁸ Center for Exoplanets and Habitable Worlds, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802, USA

Received: 1 March 2016
Accepted: 17 March 2016

Abstract

Context. We present the latest result of the TAPAS project that is devoted to intense monitoring of planetary candidates that are identified within the PennState-Toruń planet search.

Aims. We aim to detect planetary systems around evolved stars to be able to build sound statistics on the frequency and intrinsic nature of these systems, and to deliver in-depth studies of selected planetary systems with evidence of star-planet interaction processes.

Methods. The paper is based on precise radial velocity measurements: 13 epochs collected over 1920 days with the Hobby-Eberly Telescope and its High-Resolution Spectrograph, and 22 epochs of ultra-precise HARPS-N data collected over 961 days.

Results. We present a warm-Jupiter (T_eq = 1350 K, m₂ sin i = 5.4 ± 0.4 M_J) companion with an orbital period of 26.468 days in a circular (e = 0.036) orbit around a giant evolved (log g = 3.11 ± 0.09, R = 6.26 ± 0.86 R_⊙) star with M_⋆ = 1.87 ± 0.17 M_⊙. This is the most massive and oldest star found to be hosting a close-in giant planet. Its proximity to its host (a = 0.21 au) means that the planet has a 13.9 ± 2.0% probability of transits; this calls for photometric follow-up study.

Conclusions. This massive warm Jupiter with a near circular orbit around an evolved massive star can help set constraints on general migration mechanisms for warm Jupiters and, given its high equilibrium temperature, can help test energy deposition models in hot Jupiters.