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Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary.

ABSTRACT: Cool subdwarfs are metal-poor low-mass stars that formed during the early stages of the evolution of our Galaxy. Because they are relatively rare in the vicinity of the Sun, we know of few cool subdwarfs in the solar neighbourhood, and none with both the mass and the radius accurately determined. This hampers our understanding of stars at the low-mass end of the main-sequence. Here we report the discovery of SDSS J235524.29+044855.7 as an eclipsing binary containing a cool subdwarf star, with a white dwarf companion. From the light-curve and the radial-velocity curve of the binary we determine the mass and the radius of the cool subdwarf and we derive its effective temperature and luminosity by analysing its spectral energy distribution. Our results validate the theoretical mass-radius-effective temperature-luminosity relations for low-mass low-metallicity stars.

SUBMITTER: Rebassa-Mansergas A

PROVIDER: S-EPMC6558239 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary.

Rebassa-Mansergas Alberto A Parsons Steven G SG Dhillon Vikram S VS Ren Juanjuan J Littlefair Stuart P SP Marsh Thomas R TR Torres Santiago S

Nature astronomy 20190408 6

Cool subdwarfs are metal-poor low-mass stars that formed during the early stages of the evolution of our Galaxy. Because they are relatively rare in the vicinity of the Sun, we know of few cool subdwarfs in the solar neighbourhood, and none with both the mass and the radius accurately determined. This hampers our understanding of stars at the low-mass end of the main-sequence. Here we report the discovery of SDSS J235524.29+044855.7 as an eclipsing binary containing a cool subdwarf star, with a ...[more]

PMID: 31187071

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Dataset Information

Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary.

Publications

Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary.

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