V680 Mon -- a young mercury-manganese star in an eclipsing heartbeat system

Abstract

Chemically peculiar stars in eclipsing binary systems are rare objects that allow the derivation of fundamental stellar parameters and important information on the evolutionary status and the origin of the observed chemical peculiarities. Here we present an investigation of the known eclipsing binary system BD+09 1467 = V680 Mon. Using spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and own observations, we identify the primary component of the system as a mercury-manganese (HgMn/CP3) star (spectral type kB9 hB8 HeB9 V HgMn). Furthermore, photometric time series data from the Transiting Exoplanet Survey Satellite (TESS) indicate that the system is a "heartbeat star", a rare class of eccentric binary stars with short-period orbits that exhibit a characteristic signature near the time of periastron in their light curves due to the tidal distortion of the components. Using all available photometric observations, we present an updated ephemeris and binary system parameters as derived from modelling of the system with the ELISa code, which indicates that the secondary star has an effective temperature of Teff = 8300+-200 K (spectral type of about A4). V680 Mon is only the fifth known eclipsing CP3 star and the first one in a heartbeat binary. Furthermore, our results indicate that the star is located on the zero-age main sequence and a possible member of the open cluster NGC 2264. As such, it lends itself perfectly for detailed studies and may turn out to be a keystone in the understanding of the development of CP3 star peculiarities.

Accepted for publication in the Monthly Notices of the Royal Astronomical Society, 10 pages, 6 figures, 4 tables

References in corpus (14)

• The Transiting Exoplanet Survey Satellite
• Clusters and mirages: cataloguing stellar aggregates in the Milky Way
• Heartbeat Stars, Tidally Excited Oscillations, and Resonance Locking
• The asteroseismic potential of TESS: exoplanet-host stars
• Chemically peculiar stars and their temperature calibration
• Beyond the Kepler/K2 bright limit: variability in the seven brightest members of the Pleiades
• Inhomogeneous surface distribution of chemical elements in the eclipsing binary AR Aur: A new challenge for our understanding of HgMn stars
• KIC 8164262: a Heartbeat Star Showing Tidally Induced Pulsations with Resonant Locking
• Mass segregation and sequential star formation in NGC 2264 revealed by Herschel
• The SDSS/APOGEE Catalog of HgMn Stars
• New mercury-manganese stars and candidates from LAMOST DR4
• A Spectroscopic and Photometric Investigation of the Mercury-Manganese Star KIC 6128830
• Detection of weak magnetic fields in two HgMn stars
• V772 Cas: an ellipsoidal HgMn star in an eclipsing binary

Cited by in corpus (5)

• TESS survey of rotational and pulsational variability of mercury-manganese stars
• The OGLE Collection of Variable Stars. One Thousand Heartbeat Stars in the Galactic Bulge and Magellanic Clouds
• New eclipsing binaries with mercury-manganese stars
• A rare phosphorus-rich star in an eclipsing binary from TESS
• Dynamical mass determination and partial eclipses of the heartbeat star HD 181793