Astronomers discover clouds of sand in failed star’s atmosphere

(ORDO NEWS) — New observations from the James Webb Space Telescope have given us direct confirmation that rocky clouds exist on some alien worlds.

The telescope was the first to detect directly silicate clouds in the atmosphere of a brown dwarf. , according to an international team of astronomers, such a detection was made in a planetary-mass companion outside the solar system.

The full results, according to the group, represent the best spectrum for a planetary mass. mass object. These results may not only help us better understand these so-called “failed stars”, but are just a preview of what JWST can do.

The article has been submitted to AAS journals and is available on the arXiv preprint server while it is being reviewed and published.

We’ve already seen JWST take a direct image of an exoplanet, but a brown dwarf is a slightly different matter.

These objects arise when a young star does not accumulate enough mass to start hydrogen fusion in its core, and they occupy a position in mass between the most unstable planets and the smallest stars.

However, at about 13.6 times the mass of Jupiter (sorry Jupiter, you tried), brown dwarfs can fuse deuterium or heavy hydrogen—hydrogen with a proton and a neutron in the core, not just one proton.

The fusion pressure and temperature of deuterium are lower than those of hydrogen, which means that brown dwarfs are similar to light stars. ‘.

This means that, unlike exoplanets, brown dwarfs emit their own heat and light. Obviously, this is much smaller than stars, but we can detect it directly, especially in the infrared, which JWST specializes in.

Observations made by a team led by astronomer Brittany Miles of the University of California. Santa Cruz originated from the brown dwarf VHS 1256-1257 b, which is about 72 light-years away and was first described in 2015.

It has a mass about 19 times that of Jupiter and is relatively young. with a reddish atmosphere.

This hue had previously been attributed to clouds in young brown dwarfs, so the team took infrared spectra to see if they could determine the brown dwarf’s composition.

This works because different elements absorb and re-emit light at different wavelengths. Scientists can look at the spectrum to see fainter and brighter details and identify the elements that are causing them.

The atmospheric composition of VHS 1256-1257 b, the team found, was similar to that of other brown dwarfs studied at infrared wavelengths, but much clearer.

“Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium are observed in several parts of the JWST spectrum based on comparison with template brown dwarf spectra, molecular opacity, and atmospheric models,” the researchers write in their paper.

Carbon monoxide, according to the researchers, is the clearest observed. They also found, as they had hoped, clouds – long hypothetical clouds of silicate particles in a thick layer, with submicron grain sizes. The researchers note that these are likely minerals such as forsterite, enstatite, or quartz.

This seems to be conclusive evidence that young brown dwarfs may be surrounded by patchy silicate clouds that affect brightness variability.

This gives us a tool to interpret future observations of brown dwarfs and what to look for in future observations, the researchers note.

“These initial scientific observational results from the early JWST release are groundbreaking and also accessible to many other nearby brown dwarfs that will be observed in future observation cycles,” they write in their paper.

“This observatory will be a pioneer in advancing our understanding of atmospheric physics on a planetary scale. moons, brown dwarfs and exoplanets for years to come.”


Contact us: [email protected]

Our Standards, Terms of Use: Standard Terms And Conditions.