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We are resolving the orbits of spectroscopic binary stars in the Hyades Cluster using the CHARA Array. We obtained positions and flux ratios in the H-band using the MIRC-X combiner and the K-band using the recently commissioned MYSTIC combiner. We present preliminary orbital fits and mass estimates for four binary systems (HD 27691, HD 28033, HD 28294, and HD 28394). The sample consists of binaries where the primary stars have F-G spectral types and the companions are low mass stars with masses in the range of 0.3-0.9 Msun. The results will be used to test evolutionary models for low mass stars. The large mass difference between the components will provide leverage for testing the isochrones and refining the age of the Hyades cluster.
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Orbits and Dynamical Masses for Six Binary Systems in the Hyades Cluster
Abstract We report long-baseline interferometric observations with the CHARA Array that resolve six previously known double-lined spectroscopic binary systems in the Hyades cluster, with orbital periods ranging from 3 to 358 days: HD 27483, HD 283882, HD 26874, HD 27149, HD 30676, and HD 28545. We combine those observations with new and existing radial-velocity measurements, to infer the dynamical masses for the components as well as the orbital parallaxes. For most stars, the masses are determined to be better than 1%. Our work significantly increases the number of systems with mass determinations in the cluster. We find that, while current models of stellar evolution for the age and metallicity of the Hyades are able to reproduce the overall shape of the empirical mass–luminosity relation, they overestimate theV-band fluxes by about 0.1 mag between 0.5 and 1.4M⊙. The disagreement is smaller inH, and near zero inK, and depends somewhat on the model. We also make use of the TESS light curves to estimate rotation periods for our targets, and detect numerous flares in one of them (HD 283882), estimating an average flaring rate of 0.44 events per day.
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- PAR ID:
- 10536137
- Publisher / Repository:
- The Astrophysical Journal
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 971
- Issue:
- 1
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 31
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.3847/1538-4357/ad54b2
