Astronomy

Discovery of a brown dwarf hotter than the sun

June 21, 2023

Phased radial-velocity curves of WD 0032−317. a, trailed UVES spectrum for the H𝛼 line of WD 0032−317 (blue represents decrease fluxes, and yellow represents increased fluxes), folded over the orbital interval (𝑃 = 8340.9090 s). The first absorption is clearly seen in blue. The emission from the companion (in yellow) seems in anti-phase with the first, and is seen solely from the irradiated day facet, between orbital phases ∼ 0.2–0.8. Its “inverted” form, evident particularly close to quadrature, is the results of non-local thermodynamic equilibrium (NLTE) results [40]. b, radial velocity curves (prime panel) of the white dwarf (blue circles) and the irradiated companion (pink diamonds), folded over the orbital interval (𝑃 = 8340.9090 s). The first’s (secondary’s) best-fit curve is marked by the blue dashed (pink dotted) line on each panels. The underside panels present the residuals of the white-dwarf part (center) and the irradiated companion (backside). The error bars present the usual deviation. The illustrations on prime show the system’s configuration at every orbital phase. Credit score: arXiv (2023). DOI: 10.48550/arxiv.2306.08672

A world group of astronomers has found a planet-like object that’s hotter than the sun. Their report has been accepted for publication within the journal Nature Astronomy and is presently out there on the arXiv pre-print server.

Brown dwarfs are generally referred to as failed stars and don’t qualify for the class of both a planet or a star. On this new effort, the researchers have recognized one which orbits a star so carefully that its temperature is hotter than our sun.

The brown dwarf was noticed orbiting a low-mass white dwarf referred to as WD0032-317, a star with simply 40% the mass of our sun, however that’s hotter, with a temperature of roughly 37,000 Kelvin (the floor of the sun is roughly 5,778 Kelvin). The brown dwarf was subsequently named WD0032-317B and its temperature was discovered to be roughly 8,000 Kelvin, a lot hotter than different brown dwarfs, on account of its proximity to the star.

WD0032-317 was first noticed in early 2000 by a group finding out information from the European Southern Observatory’s Very Giant Telescope. Researchers famous that one thing was tugging on the star, suggesting it had a companion. The group on this new effort discovered that it was a brown dwarf, not a companion star. Its mass is roughly 75 to 88 Jupiters and it orbits quickly round its star, with a interval of simply 2.3 hours.

In addition they word that the brown dwarf is tidally locked, which ends up in sizzling temperatures on one facet (roughly 7,250 to 9,800 Kelvin) and cooler temperatures on the opposite (roughly 1,300 to three,000 Kelvin). The temperatures on the new facet are roughly 5,100 Kelvin hotter than another recognized large planet. That makes WD0032-317B the most popular recognized brown dwarf and warmer than any recognized planet. This, the researchers recommend, might yield details about how sizzling stars trigger companion objects to evaporate.

Extra data:
Na’ama Hallakoun et al, An irradiated-Jupiter analogue hotter than the Solar, arXiv (2023). DOI: 10.48550/arxiv.2306.08672

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Discovery of a brown dwarf hotter than the sun (2023, June 21)
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