DENIS 0255−4700 is an extremely faint brown dwarf 15.9 light-years (4.9 parsecs) from the Solar System in the southern constellation of Eridanus.[3][7] It is the closest isolated L-type brown dwarf (no undiscovered L-dwarfs are expected to be closer), and only after the binary Luhman 16. It is also the faintest brown dwarf (with the absolute magnitude of MV=24.44) having measured visible magnitude.[8] A number of nearer T and Y-type dwarfs are known, specifically WISE 0855−0714, Epsilon Indi B and C, SCR 1845-6357 B, and UGPS 0722−05.
History of observations
DENIS 0255−4700 was identified for the first time as a probable nearby object in 1999.[7] Its proximity to the Solar System was established by the RECONS group in 2006 when its trigonometric parallax was measured.[8] DENIS 0255-4700 has a relatively small tangential velocity of 27.0 ± 0.5 km/s.[2]
Properties
The photospheric temperature of DENIS 0255−4700 is estimated at 1300 K.[2] Its atmosphere in addition to hydrogen and helium contains water vapor, methane and possibly ammonia.[9] The mass of DENIS 0255−4700 lies in the range from 25 to 65 Jupiter masses corresponding to the age range from 0.3 to 10 billion years.[2] The brown dwarf is rotating rapidly with the period of 1.7 hours, and its rotational axis is inclined 40 degrees from the line-of-sight.[5]
^ abcdefStephens, Denise C.; Leggett, Sandy K.; Cushing, Michael C.; Marley, Mark S.; Saumon, Didier; Geballe, Thomas R.; Golimowski, David A.; Fan, Xiaohui; Noll, Keith S. (2009). "The 0.8–14.5 μm Spectra of Mid-L to Mid-T Dwarfs: Diagnostics of Effective Temperature, Grain Sedimentation, Gas Transport, and Surface Gravity". The Astrophysical Journal. 702 (1): 154–170. arXiv:0906.2991. Bibcode:2009ApJ...702..154S. doi:10.1088/0004-637X/702/1/154. S2CID118650774.
^ abcdCifuentes, C.; Caballero, J. A.; Cortés-Contreras, M.; Montes, D.; Abellán, F. J.; Dorda, R.; Holgado, G.; Zapatero Osorio, M. R.; Morales, J. C.; Amado, P. J.; Passegger, V. M.; Quirrenbach, A.; Reiners, A.; Ribas, I.; Sanz-Forcada, J. (2020-10-01). "CARMENES input catalogue of M dwarfs. V. Luminosities, colours, and spectral energy distributions". Astronomy and Astrophysics. 642: A115. arXiv:2007.15077. Bibcode:2020A&A...642A.115C. doi:10.1051/0004-6361/202038295. ISSN0004-6361.
^ abCosta, E.; Méndez, R. A.; Jao, W. -C.; Henry, T. J.; Subasavage, J. P.; Ianna, P. A. (2006). "The Solar Neighborhood. XVI. Parallaxes from CTIOPI: Final Results from the 1.5 m Telescope Program". The Astronomical Journal. 132 (3): 1234. Bibcode:2006AJ....132.1234C. CiteSeerX10.1.1.622.2310. doi:10.1086/505706. S2CID18952940.
^Cushing, Michael C. (2006). "Spitzer Space Telescope Observations of M, L, and T Dwarfs". ASP Conference Series. 357: 66–67. Bibcode:2006ASPC..357...66C.