A transiting M-dwarf showing beaming effect in the field of Ruprecht 147

Abstract

We report the discovery and characterization of an eclipsing M5V dwarf star, orbiting a slightly evolved F7V main sequence star. In contrast to previous claims in the literature, we confirm that the system does not belong to the galactic open cluster Ruprecht 147. We determine its fundamental parameters combining K2 time-series data with spectroscopic observations from the McDonald Observatory, FIES@NOT, and HIRES@KECK. The very precise photometric data from the K2 mission allows us to measure variations caused by the beaming effect (relativistic doppler boosting), ellipsoidal variation, reflection, and the secondary eclipse. We determined the radial velocity using spectroscopic observations and compare it to the radial velocity determined from the beaming effect observed in the photometric data. The M5V star has a radius of $0.200\begin{array}{c}+0.007\\ -0.008\end{array}$ $R_{\odot }$ and a mass of $0.187\begin{array}{c}+0.012\\ -0.013\end{array}$ $M_{\odot }$. The primary star has radius of $1.518\begin{array}{c}+0.038\\ -0.049\end{array}$ $R_{\odot }$ and a mass of $1.008\begin{array}{c}+0.081\\ -0.097\end{array}$ $M_{\odot }$. The orbital period is $5.441995\pm 0.000007$ days. The system is one of the few eclipsing systems with observed beaming effect and spectroscopic radial velocity measurements and it can be used as test case for the modelling of the beaming effect. Current and forthcoming space missions such as TESS and PLATO might benefit of the analysis of the beaming effect to estimate the mass of transiting companions without the need for radial velocity follow up observations, provided that the systematic sources of noise affecting this method are well understood.

accepted for publication in MNRAS, https://doi.org/10.1093/mnras/sty2155 8 pages

References in corpus (12)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Dartmouth Stellar Evolution Database
• How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
• Precision Stellar Characterization of FGKM Stars using an Empirical Spectral Library
• Stellar parameters and chemical abundances of 223 evolved stars with and without planets
• New low-mass eclipsing binary systems in Praesepe discovered by K2
• A study of the performance of the transit detection tool DST in space-based surveys. Application of the CoRoT pipeline to Kepler data
• BEER analysis of Kepler and CoRoT light curves: IV. Discovery of four new low-mass white dwarf companions in the Kepler data
• K2-99: a subgiant hosting a transiting warm Jupiter in an eccentric orbit and a long-period companion
• K2-98 b: A 32-M${}_{\oplus }$ Neptune-sized planet in a 10-day orbit transiting an F8 star
• Masses and radii of four very low mass stars in F+M eclipsing binary systems
• K2-60b and epic 216468514b. A sub-jovian and a jovian planet from the k2 mission

Cited by in corpus (3)

• NGTS-7Ab: An ultra-short period brown dwarf transiting a tidally-locked and active M dwarf
• Search for Dormant Black Holes in Ellipsoidal Variables I. Revisiting the Expected Amplitudes of the Photometric Modulation
• Analysis of TESS field eclipsing binary star V948 Her: a pulsating or non-pulsating star?