The BANANA project. V. Misaligned and precessing stellar rotation axes in CV Velorum

Abstract

As part of the BANANA project (Binaries Are Not Always Neatly Aligned), we have found that the eclipsing binary CV Velorum has misaligned rotation axes. Based on our analysis of the Rossiter-McLaughlin effect, we find sky-projected spin-orbit angles of ${\beta }_{\mathrm{p}}=-52\pm 6^{\circ }$ and ${\beta }_{\mathrm{s}}=3\pm 7^{\circ }$ for the primary and secondary stars (B2.5V $+$ B2.5V, $P=6.9$ d). We combine this information with several measurements of changing projected stellar rotation speeds ($v\sin i_{\star }$) over the last $30$ years, leading to a model in which the primary star's obliquity is $\approx 65^{\circ }$, and its spin axis precesses around the total angular momentum vector with a period of about $140$ years. The geometry of the secondary star is less clear, although a significant obliquity is also implicated by the observed time variations in the $v\sin i_{\star }$. By integrating the secular tidal evolution equations backward in time, we find that the system could have evolved from a state of even stronger misalignment similar to DI Herculis, a younger but otherwise comparable binary.

Accepted for publication in ApJ; 11 pages, 12 figures

References in corpus (3)

• Tidal dissipation within hot Jupiters: a new appraisal
• The spin axes orbital alignment of both stars within the eclipsing binary system V1143Cyg using the Rossiter-McLaughlin effect
• The early-type close binary CV Velorum revisited

Cited by in corpus (21)

• Mergers and Obliquities in Stellar Triples
• Stellar obliquities in exoplanetary systems
• The Formation and Gravitational-Wave Detection of Massive Stellar Black-Hole Binaries
• Planets Transiting Non-Eclipsing Binaries
• First Results From The Hertzsprung Song Telescope: Asteroseismology Of The G5 Subgiant Star {\Mu}Her
• The EBLM Project IV. Spectroscopic orbits of over 100 eclipsing M dwarfs masquerading as transiting hot-Jupiters
• Chaotic Dynamics of Stellar Spin in Binaries and the Production of Misaligned Hot Jupiters
• A Misaligned Prograde Orbit for Kepler-13 Ab via Doppler Tomography
• Rossiter--McLaughlin models and their effect on estimates of stellar rotation, illustrated using six WASP systems
• Eccentricity and Spin-Orbit Misalignment in Short-Period Stellar Binaries as a Signpost of Hidden Tertiary Companions
• Time variation of Kepler transits induced by stellar rotating spots - a way to distinguish between prograde and retrograde motion I. Theory
• KIC 8164262: a Heartbeat Star Showing Tidally Induced Pulsations with Resonant Locking
• Temperature and Distance Dependence of Tidal Circularization in Close Binaries: A Catalog of Eclipsing Binaries in the Southern Hemisphere Observed by the TESS Satellite
• The spin-orbit alignment of visual binaries
• The PLATO field selection process. II. Characterization of LOPS2, the first long-pointing field
• The EBLM project. VII. Spin-orbit alignment for the circumbinary planet host EBLM J0608-59 A/TOI-1338 A
• THE BANANA PROJECT. VI. Close double stars are well aligned with noticeable exceptions; results from an ensemble study using apsidal motion and Rossiter-McLaughlin measurements
• Study of rotational splittings in $\delta$~Scuti stars using pattern finding techniques
• KOI-3890: A high mass-ratio asteroseismic red-giant$+$M-dwarf eclipsing binary undergoing heartbeat tidal interactions
• Projected spin-orbit alignments from Kepler asteroseismology and Gaia astrometry
• Spin-spin coupling in stellar binaries