Scientists have carried out a new study with the aim to answer many boiling questions surrounding brown dwarfs. A brown dwarf is an object that has a mass between that of a planet and a star. One of the questions the study tries to answer is where the mass limit lies. The question is the subject of debate because brown dwarfs are similar to low-mass stars.
Astronomers are trying to understand how to figure out the difference between a brown dwarf and a very low mass star. Scientists at the University of Geneva and the Swiss National Center of Confidence in Research PlanetS and from the University of Bern have identified five objects that are said to have masses near the limit that differentiates stars and brown dwarfs.
Bigger than planets, smaller than stars
The team believes these objects could allow them to learn the nature of a brown dwarf. Jupiter along with other gas giant planets is made of mostly hydrogen and helium. Stars are made of similar materials but are so huge in size and the high gravitational force that hydrogen atoms inside them fuse, releasing helium that eventually results in energy and light.
By comparison, brown dwarfs aren’t huge enough to produce heat and light like stars. However, they can fuse deuterium, which is a heavy atomic version of hydrogen. Since that process is not as powerful as fusing hydrogen atoms to produce helium, the brown dwarf produces less light and heat.
Five objects identified using TESS
The team believes that the mass limits for a brown dwarf might differ depending on its chemical composition. They may also differ depending on how they form and their initial radius. Researchers studied multiple examples in detail to understand more about the brown dwarfs, but they are rare.
As of now, only 30 brown dwarfs have been identified. However, the team characterized five companions that were identified using TESS as TESS objects of interest (TOI). They include TOI-148, TOI-587, TOI-681, TOI-746 and TOI-1213. All of them orbit their respective stars in an orbital span of 5 to 27 days.
