HD207897 b: A dense sub-Neptune transiting a nearby and bright K-type star

Files

2110.08597.pdf (1.69 MB)

Links to Files

https://arxiv.org/abs/2110.08597

Permanent Link

http://hdl.handle.net/11603/23304

Collections

UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II)
UMBC Faculty Collection
UMBC Physics Department

Author/Creator

Author/Creator ORCID

https://orcid.org/0000-0001-7139-2724

Date

2021-10-16

Type of Work

journal articles
preprints
Text

Department

Program

Citation of Original Publication

Heidari, N. et al.; HD207897 b: A dense sub-Neptune transiting a nearby and bright K-type star; Astronomy and Astrophysics, 16 October, 2021;

Rights

This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Attribution 4.0 International (CC BY 4.0)
©ESO 2021

Subjects

Abstract

We present the discovery and characterization of a transiting sub-Neptune orbiting with a 16.20 day period around a nearby (28 pc) and bright(V=8.37) K0V star HD207897 (TOI-1611). This discovery is based on photometric measurements from the Transiting Exoplanet Survey Satellite(TESS) mission and radial velocity (RV) observations from the SOPHIE, Automated Planet Finder (APF) and HIRES high precision spectrographs. We used EXOFASTv2 for simultaneously modeling the parameters of the planet and its host star, combining photometric and RV data to determine the planetary system parameters. We show that the planet has a radius of 2.50+/-0.08 RE and a mass of either 14.4+/-1.6 ME or 15.9+/-1.6 ME with nearly equal probability; the two solutions correspond to two possibilities for the stellar activity period. Hence, the density is either 5.1+/-0.7 g cm^-3 or 5.5^{+0.8}_{-0.7} g cm^-3, making it one of the relatively rare dense sub-Neptunes. The existence of such a dense planet at only 0.12 AU from its host star is unusual in the currently observed sub-Neptune (2<RE<4) population. The most likely scenario is that this planet has migrated to its current position.