JWST observations shed more light on the properties of a nearby brown dwarf

Utilizing NASA’s James Webb House Telescope (JWST), astronomers have noticed a close-by brown dwarf often known as HD 19467 B. Outcomes of the observational marketing campaign, printed January 26 on the arXiv pre-print server, yield vital insights into the properties of this substellar object.

Brown dwarfs are intermediate objects between planets and stars. Astronomers typically agree that they’re substellar objects occupying the mass vary between 13 and 80 Jupiter plenty. One subclass of brown dwarfs (with efficient temperatures between 500 and 1,500 Okay) is called T dwarfs, and represents the good and least luminous substellar objects to date detected.

Research of T dwarfs may assist astronomers higher perceive objects close to the disputed planet/star boundary, as an illustration, large exoplanets. Nevertheless, though many brown dwarf have been detected so far, T dwarfs usually are not so frequent, as solely about 400 such objects have been recognized.

At a distance of some 100 light years from the Earth, HD 19467 B is a late T dwarf with a floor temperature of about 1,000 Okay. It orbits HD 19467—a sun-like star of spectral sort G3V, estimated to be between 5.4 and 12 billion years outdated. The star’s efficient temperature was measured to be roughly 5,750 Okay.

A crew of astronomers led by Alexandra Z. Greenbaum of the California Institute of Know-how (Caltech) used JWST to carry out medium/slender band imaging and photometry of HD 19467 and its companion, hoping to unveil elementary parameters of the brown dwarf. The research was complemented by information from NASA’s Transiting Exoplanet Survey Satellite tv for pc (TESS).

“We noticed HD 19467 B with JWST’s NIRCam in six filters spanning 2.5–4.6 µm with the Lengthy Wavelength Bar coronagraph…. JWST observations of the G3V star HD 19467 with its T5+ brown dwarf companion, HD 19467 B, symbolize one of many earliest workout routines of the NIRCam Coronagraphic LW Bar, offering a possibility for an early scientific end result and an indication of the capabilities of the instrument,” the researchers wrote within the paper.

The observations allowed the crew to constrain the properties of HD 19467, notably its age. The outcomes counsel that the host star is roughly 9.4 billion years outdated. The star’s radius was measured to be about 1.2 solar radii, whereas its mass was estimated to be some 0.96 solar masses.

In line with the research, the dynamical mass of the brown dwarf was calculated to be at a stage of 81 Jupiter plenty and its model-derived mass was estimated to be 62 Jupiter plenty. The researchers famous that the radius of HD 19467 B is at a stage of 0.62 Jupiter radii and that its floor temperature is roughly 10,800 Okay.

Greenbaum’s crew plans additional JWST observations of HD 19467 B, later this 12 months, with the principle intention of characterizing the environment of this brown dwarf.

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