2MASS J05352184−0546085
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 35m 21.84732s |
| Declination | −05° 46′ 08.5714″ |
| Characteristics | |
| Evolutionary stage | brown dwarf |
| Spectral type | M6.5±0.5 |
| Apparent magnitude (J) | 14.65±0.03 |
| Apparent magnitude (H) | 13.90±0.04 |
| Apparent magnitude (K) | 13.47±0.03 |
| Variable type | eclipsing binary |
| Astrometry | |
| Proper motion (μ) | RA: 1.960 mas/yr Dec.: −0.049 mas/yr |
| Parallax (π) | 2.6730±0.2658 mas |
| Distance | 1,200 ± 100 ly (370 ± 40 pc) |
| Orbit | |
| Period (P) | 9.779556(19) d |
| Semi-major axis (a) | 0.0407±0.0008 AU |
| Eccentricity (e) | 0.3216±0.0019 |
| Inclination (i) | 88.49±0.06° |
| Argument of periastron (ω) (secondary) | 215.3±0.5° |
| Semi-amplitude (K1) (primary) | 18.61±0.55 km/s |
| Semi-amplitude (K2) (secondary) | 29.14±1.40 km/s |
| Details | |
| A | |
| Mass | 0.0572±0.0033 M☉ |
| Radius | 0.690±0.011 R☉ |
| Surface gravity (log g) | 3.52±0.03 cgs |
| Temperature | 2715±200 K |
| Rotation | 3.293±0.001 d |
| Rotational velocity (v sin i) | 10 km/s |
| Age | ~1 Myr |
| B | |
| Mass | 0.0366±0.0022 M☉ |
| Radius | 0.540±0.009 R☉ |
| Surface gravity (log g) | 3.54±0.03 cgs |
| Temperature | ~2850 K |
| Rotation | 14.05±0.05 d |
| Rotational velocity (v sin i) | <5 km/s |
| Age | ~1 Myr |
| Other designations | |
| V2384 Ori, 2MASS J05352184-0546085 | |
| Database references | |
| SIMBAD | data |
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, 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. 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.
Unexpectedly, the less massive (secondary) brown dwarf is the hotter of the pair. Possible explanations for this temperature reversal include the two brown dwarfs differing slightly in age; strong magnetic fields on the primary inhibiting convection, supported by the primary's observed fast rotation and strong hydrogen-alpha emission; large starspots on the primary, though this was found to be unsupported by evidence; and tidal heating, which is unlikely to be solely responsible for the temperature reversal.
No infrared excess that would indicate the presence of a circumstellar disk has been detected in this system. The system is a source of X-ray emission.