Constellation Eridanus | ||
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2MASS J04151954-0935066 (also abbreviated to 2MASS 0415-0935) is a brown dwarf of spectral class T8, in the constellation Eridanus about 18.6 light-years from Earth.
Contents
Discovery
2MASS 0415-0935 was discovered in 2002 by Adam J. Burgasser et al. from Two Micron All-Sky Survey (2MASS), conducted from 1997 to 2001. Follow-up obsrevations were made in 1998—2001 using the Near-Infrared Camera, mounted on the Palomar 60 inch (1.5 m) Telescope; CTIO Infrared Imager (CIRIM) and Ohio State Infrared Imager/Spectrometer (OSIRIS), mounted on the Cerro Tololo Inter-American Observatory (CTIO) 1.5 m Telescope; and some additional observations were made using the Near Infrared Camera (NIRC), mounted on the Keck I 10 m telescope, and nearinfrared camera D78, mounted on the Palomar 5 m Hale Telescope. In 2002 Burgasser et al. published a paper, where they defined new spectral subtypes T1—T8, and presented discovery of 11 new T-type brown dwarfs, among which also was 2MASS 0415-0935 — object of the latest known by the time spectral type T8. These 11 objects were among the earliest T-type brown dwarfs ever discovered: before this, the total number of known T-type objects was 13, and these discoveries increased it up to 24 (apart from additional T-type dwarfs, identified by Geballe et al. 2001 in SDSS data).
Distance
Currently the most precise distance estimate of 2MASS 0415-0935 is published in 2012 by Dupuy & Liu trigonometric parallax, measured under The Hawaii Infrared Parallax Program: 175.2 ± 1.7 milliseconds of arc, corresponding to a distance 5.71 ± 0.05 pc, or 18.62 ± 0.18 ly. A less precise parallax of this object, measured under U.S. Naval Observatory Infrared Astrometry Program, was published in 2004 by Vrba et al.
Space motion
Position of 2MASS 0415-0935 shifts due to its proper motion by 2.2553 arcseconds per year (2.2782 ± 0.0012 arcsec, according to Dupuy & Liu (2012)).
Properties
2MASS 0415-0935 belongs to the spectral class T8V; its surface temperature is 600-750 Kelvin. As with other brown dwarfs of spectral type T, its spectrum is dominated by methane. The Research Consortium On Nearby Stars (RECONS) estimates the brown dwarf to be 0.03 solar masses.