English

A Dance with Dragons: TESS reveals $\alpha$ Draconis is a detached eclipsing binary

Solar and Stellar Astrophysics 2019-10-30 v2

Abstract

Detached eclipsing binaries allow stellar masses and radii to be measured with unrivalled accuracy. While inspecting light curves obtained with the Transiting Exoplanet Survey Satellite (TESS), we noticed that the A0 III star α\alpha Dra shows clear and well-separated primary and secondary eclipses. This star is known to be a single-lined spectroscopic binary, with a period of 51.5 d and an eccentricity of 0.43. The currently available TESS observations cover two 27-d sectors and the light curve shows a primary eclipse (depth 9%) and a secondary eclipse (depth 2%), separated in time by 38.5 days. Additional TESS observations of α\alpha Dra will come from TESS Sectors 16, 21 and 22, and we predict that an eclipse will be visible in each of these. With a VV magnitude of 3.68, α\alpha Dra is one of the brightest known detached eclipsing binaries.

Keywords

Cite

@article{arxiv.1910.12449,
  title  = {A Dance with Dragons: TESS reveals $\alpha$ Draconis is a detached eclipsing binary},
  author = {Timothy R. Bedding and Daniel R. Hey and Simon J. Murphy},
  journal= {arXiv preprint arXiv:1910.12449},
  year   = {2019}
}

Comments

to appear in Research Notes of the AAS

R2 v1 2026-06-23T11:56:43.364Z