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Through the combination of high-order Adaptive Optics and coronagraphy, we report the discovery of a faint stellar companion to the A3V star zeta Virginis. This companion is ~7 magnitudes fainter than its host star in the H-band, and infrared imaging spanning 4.75 years over five epochs indicates this companion has common proper motion with its host star. Using evolutionary models, we estimate its mass to be 0.168+/-.016 solar masses, giving a mass ratio for this system q = 0.082. Assuming the two objects are coeval, this mass suggests a M4V-M7V spectral type for the companion, which is confirmed through integral field spectroscopic measurements. We see clear evidence for orbital motion from this companion and are able to constrain the semi-major axis to be greater than 24.9 AU, the period > 124$ yrs, and eccentricity > 0.16. Multiplicity studies of higher mass stars are relatively rare, and binary companions such as this one at the extreme low end of the mass ratio distribution are useful additions to surveys incomplete at such a low mass ratio. Moreover, the frequency of binary companions can help to discriminate between binary formation scenarios that predict an abundance of low-mass companions forming from the early fragmentation of a massive circumstellar disk. A system such as this may provide insight into the anomalous X-ray emission from A stars, hypothesized to be from unseen late-type stellar companions. Indeed, we calculate that the presence of this M-dwarf companion easily accounts for the X-ray emission from this star detected by ROSAT.
We report the discovery of an L dwarf companion to the A3V star beta{} Circini. VVV J151721.49-585131.5, or beta{} Cir B, was identified in a proper motion and parallax catalogue of the Vista Variables in the V{i}a L{a}ctea survey as having near infr
We report the discovery of a wide co-moving substellar companion to the nearby ($D=67.5pm1.1$ pc) A3V star $zeta$ Delphini based on imaging and follow-up spectroscopic observations obtained during the course of our Volume-limited A-Star (VAST) multip
Radial velocity (RV) searches for exoplanets have surveyed many of the nearest and brightest stars for long-term velocity variations indicative of a companion body. Such surveys often detect high-amplitude velocity signatures of objects that lie outs
Context. High contrast imaging has thoroughly combed through the limited search space accessible with first-generation ground-based adaptive optics instruments and the Hubble Space Telescope. Only a few objects were discovered, and many non-detection
The $sim500$, Myr A2IV star HR 1645 has one of the most significant low-amplitude accelerations of nearby early-type stars measured from a comparison of the {it Hipparcos} and {it Gaia} astrometric catalogues. This signal is consistent with either a