Poster Open Access

# The Multiple-component Binary Hyad, vA 351

G. Fritz Benedict; Otto Franz; Elliot Horch; Guillermo Torres; L. Prato

### Dublin Core Export

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<dc:creator>G. Fritz Benedict</dc:creator>
<dc:creator>Otto Franz</dc:creator>
<dc:creator>Elliot Horch</dc:creator>
<dc:creator>Guillermo Torres</dc:creator>
<dc:creator>L. Prato</dc:creator>
<dc:date>2021-02-24</dc:date>
<dc:description>We extend results first announced by Franz et al. (1998), that identified vA351 = H346 in the Hyades as a multiple star system containing a white dwarf. With Hubble Space Telescope Fine Guidance Sensor fringe tracking and scanning, and more recent speckle observations, all spanning 20.7 years, we establish a parallax, relative orbit, and mass fraction for two components, with a period, P = 2.70y and total mass 2.1M⊙. With ground-based radial velocities, we find that component B consists of BC, two M dwarf stars orbiting with a very short period (PBC = 0.749 days), having a mass ratio MC/MB=0.95. We confirm that the total mass of the system can only be reconciled with the distance and component photometry by including a fainter, higher mass component. The quadruple system consists of three M dwarfs (A,B,C) and one white dwarf (D); MA=0.57M⊙, MB=0.48M⊙, and MC=0.45M⊙. The WD mass, 0.53M⊙, comes from cooling models, an assumed Hyades age of 670My, and consistency with all previous and derived astrometric, photometric, and RV results. Velocities from Hα and He I emission lines confirm the BC period derived from absorption lines, with similar (HeI) and higher (Hα) velocity amplitudes. We ascribe the larger Hα amplitude to emission from a region each component shadows from the other, depending on the line of sight.</dc:description>
<dc:description>Paper submitted to Astronomical Journal</dc:description>
<dc:identifier>https://zenodo.org/record/4560663</dc:identifier>
<dc:identifier>10.5281/zenodo.4560663</dc:identifier>
<dc:identifier>oai:zenodo.org:4560663</dc:identifier>
<dc:relation>doi:10.5281/zenodo.4560662</dc:relation>
<dc:relation>url:https://zenodo.org/communities/coolstars20half</dc:relation>
<dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
<dc:title>The Multiple-component Binary Hyad, vA 351</dc:title>
<dc:type>info:eu-repo/semantics/conferencePoster</dc:type>
<dc:type>poster</dc:type>
</oai_dc:dc>

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