Context: Scientists have discovered an extremely rare quadruple star system in the Milky Way. The system known as UPM J1040-3551 AabBab consists of a pair of cold brown dwarfs orbiting a pair of young red dwarf stars.
Relevance of the Topic: Prelims: Key facts about Dwarf stars.
What are Brown Dwarfs?
- Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main-sequence stars.
- They form like stars from collapsing clouds of gas and dust. Their atmospheres can consist of clouds and molecules like H2O. Their mass is approximately 13 to 80 times that of Jupiter.
- They are not massive enough to sustain nuclear fusion of Hydrogen into Helium in their cores (unlike the main-sequence stars). So, they are often known as “failed stars”. However, they emit some light and heat from the fusion of deuterium (2H).
Why are Brown Dwarfs difficult to detect?
- Brown dwarfs can be difficult to detect as they are cold and faint. As a result, astronomers typically search for brown dwarfs orbiting companion stars, which often burn brighter. Measuring the brighter stars can be useful for estimating the properties of the fainter brown dwarfs, like their age, temperature and composition.
Brown dwarfs are usually single, and hence the current findings are exciting because the chances of a low-mass brown dwarf having a companion are less than 5%.
Why do scientists study Brown Dwarfs?
- Brown dwarfs can help astronomers better understand the conditions that are necessary for the formation of stars and planets.
- Determining the abundance and distribution of brown dwarfs gives key information on the distribution of mass in the universe to astronomers (much of the universe’s mass has thus far been undetectable and is known as dark matter).
The findings would help in better understanding brown dwarfs which are difficult to detect and examine.