For the first time, the James Webb Space Telescope (JWST) has identified potential brown dwarfs outside the Milky Way, specifically in the Small Magellanic Cloud, located approximately 200,000 light-years from Earth. This discovery marks a significant advancement in our understanding of these substellar objects, which were theorized over 60 years ago but only observed in our galaxy until now.
The findings, detailed in a recent publication in The Astrophysical Journal, stemmed from observations of the young star cluster NGC 602. The JWST's exceptional sensitivity and spatial resolution allowed researchers to detect these distant brown dwarf candidates.
Peter Zeidler, the lead author from AURA/STScI for the European Space Agency, emphasized that such detections were previously impossible from Earth and highlight the capabilities of the JWST. Elena Manjavacas, another team member, noted that prior to this, only about 3,000 brown dwarfs were known, all within our galaxy.
The research team, including Antonella Nota, pointed out the collaborative power of Hubble and Webb in studying young star clusters. While Hubble revealed the presence of very young low-mass stars in NGC 602, Webb provided insights into the extent of substellar mass formation in the cluster.
These brown dwarfs provide a unique opportunity to study star formation under conditions similar to those in the early universe, with low abundances of elements heavier than hydrogen and helium. The findings bring us closer to understanding the formation of stars and planets in the challenging environments of the primordial universe.
Theoretical predictions of brown dwarfs date back to the work of Indian astronomer Shiv S. Kumar between 1958 and 1962, who referred to them as black dwarfs. These objects are too massive to be gas giants like Jupiter but not massive enough to be classified as stars, leading to their designation as brown dwarfs.
Brown dwarfs serve as valuable subjects for studying the evolution and atmospheres of giant planets, as lighter brown dwarfs and Jupiter-like planets may exhibit similar characteristics.