An international team of astronomers, led by the Institute of Astrophysics in the Canary Islands, has identified the most massive brown dwarf ever seen. Beside its massiveness, this dwarf’s composition turns out to be what scientist called the purest dwarf. A record breaking brown dwarf is located 750 light years away, in the Pisces constellation.
Brown dwarfs are known as failed stars. They belong to substellar objects, with size intermediate between stars and gaseous giant planets. However, their mass and density aren’t enough to trigger hydrogen fusion in their core to become a fully-fledged star. This inability of nuclear fusion causes cooling brown dwarf which leads to the possibility to support the atmosphere with methane and water vapor. That’s why some scientists believe dwarfs could be the hosts of some sort of alien life.
The brown dwarf named SDSS J0104+1535, classified as M-class dwarf ( the coolest stars ) was discovered back in 1992 and since then observed. Before measurements, scientists thought it was the typical representative of its kind. However, after measurements, they figure out that this object broke records among failed stars.
It turns out that this dwarf consists more than 99,99 % of hydrogen and helium, which makes it 250 times purer than our Sun. Estimated to have formed about 10 billion years ago, measurements also suggest it has a mass equivalent to 90 times that of Jupiter, making it the most massive brown dwarf found to date.
The team led by astrophysicist ZengHua Zhang have used Very Large Telescope (VLT) at the European Southern Observatory in Chile. Thanks to advanced features of VLT astronomers were able to precisely measure optical and near infrared spectrum of SDSS J0104+1535. Now it is classified as L-class dwarf due to its lack of metallicity that M class stars usually contain.
Dr. Zang adds in research papers: “We really didn’t expect to see brown dwarfs that are this pure. Having found one though often suggests a much larger hitherto undiscovered population. I’d be very surprised if there aren’t many more similar objects out there waiting to be found.”