2MASS J05352184−0546085

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.

2MASS J05352184−0546085

Artist's impression of the 2M0535-05 system
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
Right ascension 05h 35m 21.84732s[1]
Declination −05° 46′ 08.5714″[1]
Characteristics
Evolutionary stage brown dwarf
Spectral type M6.5±0.5[2]
Apparent magnitude (J) 14.65±0.03[3]
Apparent magnitude (H) 13.90±0.04[3]
Apparent magnitude (K) 13.47±0.03[3]
Variable type eclipsing binary
Astrometry
Proper motion (μ) RA: 1.960 mas/yr[1]
Dec.: -0.049 mas/yr[1]
Parallax (π)2.6730 ± 0.2658 mas[1]
Distance1,200 ± 100 ly
(370 ± 40 pc)
Orbit[4]
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[4]
A
Mass0.0572±0.0033 M
Radius0.690±0.011 R
Surface gravity (log g)3.52±0.03 cgs
Temperature2715±200 K
Rotation3.293±0.001 d
Rotational velocity (v sin i)10[2] km/s
Age~1 Myr
B
Mass0.0366±0.0022 M
Radius0.540±0.009 R
Surface gravity (log g)3.54±0.03 cgs
Temperature~2850[a] K
Rotation14.05±0.05 d
Rotational velocity (v sin i)<5[2] km/s
Age~1 Myr
Other designations
V2384 Ori, 2MASS J05352184-0546085[3]
Database references
SIMBADdata
Light curves for V2384 Orionis in three infrared bands. Representative error bars are shown in violet. Plotted from data published by Gómez Maqueo Chew et al. (2009)[4]

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]

See also

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  • 2M1510, another eclipsing binary brown dwarf

Notes

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  1. ^ Derived from the primary temperature of 2715 K and the secondary/primary temperature ratio of 1.050

References

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  1. ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d e f Stassun, Keivan G.; Mathieu, Robert D.; Valenti, Jeff A. (August 2007). "A Surprising Reversal of Temperatures in the Brown Dwarf Eclipsing Binary 2MASS J05352184-0546085". The Astrophysical Journal. 664 (2): 1154–1166. arXiv:0704.3106. Bibcode:2007ApJ...664.1154S. doi:10.1086/519231.
  3. ^ a b c d "V* V2384 Ori". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 May 2024.
  4. ^ a b c d e f Gómez Maqueo Chew, Yilen; Stassun, Keivan G.; Prša, Andrej; Mathieu, Robert D. (July 2009). "Near-infrared Light Curves of the Brown Dwarf Eclipsing Binary 2MASS J05352184-0546085: Can Spots Explain the Temperature Reversal?". The Astrophysical Journal. 699 (2): 1196–1208. arXiv:0905.0491. Bibcode:2009ApJ...699.1196G. doi:10.1088/0004-637X/699/2/1196.
  5. ^ Stassun, Keivan G.; Mathieu, Robert D.; Valenti, Jeff A. (March 2006). "Discovery of two young brown dwarfs in an eclipsing binary system". Nature. 440 (7082): 311–314. Bibcode:2006Natur.440..311S. doi:10.1038/nature04570.
  6. ^ a b c "Astronomers Measure Precise Mass of a Binary Brown Dwarf". hubblesite.org. STScI. 15 March 2006. Retrieved 8 May 2024.
  7. ^ Reiners, A.; Seifahrt, A.; et al. (December 2007). "Detection of Strong Activity in the Eclipsing Binary Brown Dwarf 2MASS J05352184-0546085: A Possible Explanation for the Temperature Reversal". The Astrophysical Journal. 671 (2): L149–L152. arXiv:0711.0536. Bibcode:2007ApJ...671L.149R. doi:10.1086/525255.
  8. ^ Mohanty, Subhanjoy; Stassun, Keivan G. (October 2012). "High-resolution Spectroscopy during Eclipse of the Young Substellar Eclipsing Binary 2MASS 0535-0546. II. Secondary Spectrum: No Evidence that Spots Cause the Temperature Reversal". The Astrophysical Journal. 758 (1): 12. arXiv:1208.0300. Bibcode:2012ApJ...758...12M. doi:10.1088/0004-637X/758/1/12.
  9. ^ Heller, R.; Jackson, B.; et al. (May 2010). "Tidal effects on brown dwarfs: application to the eclipsing binary 2MASS J05352184-0546085. The anomalous temperature reversal in the context of tidal heating". Astronomy and Astrophysics. 514: A22. arXiv:1002.1246. Bibcode:2010A&A...514A..22H. doi:10.1051/0004-6361/200912826.
  10. ^ Mohanty, Subhanjoy; Stassun, Keivan G.; Mathieu, Robert D. (May 2009). "Circumstellar Environment and Effective Temperature of the Young Substellar Eclipsing Binary 2MASS J05352184-0546085". The Astrophysical Journal. 697 (1): 713–720. arXiv:0903.1892. Bibcode:2009ApJ...697..713M. doi:10.1088/0004-637X/697/1/713.

Further reading

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