2MASS_J05352184–0546085
2MASS J05352184−0546085
Eclipsing binary brown dwarf in the Orion Nebula
2MASS J05352184-0546085, abbreviated to 2M0535-05 and also known by its variable star designation V2384 Orionis, is a young eclipsing binary brown dwarf system in the Orion Nebula, about 1,200 light-years (370 parsecs) away. It was discovered in 2006 and was the first eclipsing brown dwarf system to be discovered,[5][6] predating the discovery of the transiting brown dwarf CoRoT-3b in 2008.
The pair orbit each other with a period of 9.8 days, and are about 60 and 38 times the mass of Jupiter, respectively. The system is very young, at an age of about 1 million years, so the brown dwarfs have yet to cool; they are M-type objects with temperatures comparable to red dwarf stars, and they are inflated in size to over half the radius of the Sun.[4][6] The primary is observed to rotate with a period of 3.3 days and the secondary 14 days, indicating that they have not yet become tidally locked to each other.[4]
Unexpectedly, the less massive (secondary) brown dwarf is the hotter of the pair.[6][2] Possible explanations for this temperature reversal include the two brown dwarfs differing slightly in age;[2] strong magnetic fields on the primary inhibiting convection,[2] supported by the primary's observed fast rotation and strong hydrogen-alpha emission;[7] large starspots on the primary,[4] though this was found to be unsupported by evidence;[8] and tidal heating, which is unlikely to be solely responsible for the temperature reversal.[9]
No infrared excess that would indicate the presence of a circumstellar disk has been detected in this system.[10]