Illustration of a brown dwarf. Image: NASA’s Goddard Space Flight Center.
According to a study published on the arXiv database and expected to be published in the journal Nature Astronomy, the newly discovered brown dwarf boasts a temperature of about 7,730 degrees Celsius, whereas the surface temperature of the Sun is approximately 5,500 degrees Celsius, as reported by Newsweek on June 20th. An international team
of experts, led by astrophysicist Na’ama Hallakoun from the Weizmann Institute of Science in Israel, has named this celestial body WD0032-317B.
Brown dwarfs are celestial objects that are half star, half planet, sometimes referred to as “failed stars.” They are gigantic gas balls typically with masses ranging from 13 to 80 times that of Jupiter, yet they lack the mass required to sustain the nuclear fusion process necessary to become a true star like the Sun.
Brown dwarfs usually have much cooler temperatures than WD0032-317B, setting a record as the hottest observed brown dwarf to date. Brown dwarfs typically have temperatures between 480 and 1,930 degrees Celsius because their energy production is insufficient compared to a full-fledged star. WD0032-317B has a mass 75 to 88 times that of Jupiter and orbits its host star in just 2.3 hours.
WD0032-317B’s unusual heat is attributed to its close proximity to its host star and the substantial exposure to ultraviolet radiation on its surface. This can lead to a process called thermal dissociation, causing the atmosphere of the celestial body to evaporate, and its molecules to be torn apart. Another example of an object moving closely to its host star to the point of undergoing thermal dissociation is KELT-9b, a giant gas exoplanet with a surface temperature of around 4,430 degrees Celsius on its sun-facing side.
The research team hopes that this new discovery might provide insights into the conditions on giant gas planets like Jupiter, such as KELT-9b, which orbit massive and super-hot stars. Observing these planets has proven to be extremely challenging due to their close proximity to their host stars.