Brown Dwarf

An international team of astronomers have discovered the first aurora outside the solar system around a brown dwarf which is approximately 18 light years away from Earth and about 10,000 times more powerful than any previously seen. An aurora is a natural light display which is predominantly seen in the high altitude regions of earth. Astronomers described the aurora to be similar to the famous ‘Northern Lights’ which in this case is not the result of a planet but of a low mass star at the boundary between stars and the brown dwarf.

The findings published in the journal Nature states that the luminous glow, although it looks like Northern Lights, is up to a million times brighter and more red than green in colour. The brown dwarf has been named LSR J1835 and it was discovered using the Very Large Array radio telescope and the Hale and Keck optical telescopes.

Astronomers state that the dwarf shows a major difference between the magnetic activity of more massive stars and that of brown dwarfs and planets. Brown dwarfs are often referred to as failed stars which are more massive than planets but are too small to trigger thermonuclear reactions. The dwarf is similar in size to that of Jupiter but is a few dozen times more massive than the largest planet of the solar system. This indicates that it is too heavy to be a planet but too light to be a star. The discovery has opened up new doors to study extrasolar planets.