OTS 44

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Brown dwarf
OTS 44
Artist's impression of OTS 44 with its protoplanetary disk
Artist's impression of OTS 44 with its protoplanetary disk
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation chameleon
Right ascension 11 h 10 m 9.34 s
declination −76 ° 32 ′ 17.9 ″
distance 554  ly
(170  pc )
Typing
Spectral class M9.5
Physical Properties
Luminosity 0.0013-0.0024 L ☉
Effective temperature 1700-2300 K
Other names
and catalog entries
Further designations:

2MASS J11100934-7632178, Cha I 27

OTS 44 is a planetary mass or brown dwarf object in the constellation Chameleon at a distance of approximately 550 light years (170 pc). It has a mass between 5 and 17 Jupiter's masses , with the most likely value at around 11.5 Jupiter's masses, or 1.1% of the Sun's mass . It is thus one of the lowest-mass substellar objects that we know of not gravitationally bound to a larger body (as of November 2014), and most likely an object of planetary mass; however, its mass is not safely below the lower limit of mass for brown dwarfs (13 masses of Jupiter). In 2004 it was described as the smallest brown dwarf known at the time, with a mass of 15 Jupiter, which is surrounded by a protoplanetary disk .

The exact radius is not known, but it is estimated to be around 23–57% of the solar radius.

It was discovered in 1998/99 by Oasa, Tamura and Sugitani, whose first letter OTS became part of its name. Mid-infrared observations made with the Spitzer Space Telescope indicate dust in the vicinity of OTS 44. The discovery of OTS 44 with the Herschel Space Telescope in the far infrared shows that OTS 44 is surrounded by a disk with at least 10 Earth masses . Observations with the SINFONI spectrograph of the Very Large Telescope show that OTS 44 attracts matter from the disk at a rate of 10 −11 solar masses per year. Both disk formation and active mass accretion are processes found in young stars. These discoveries suggest that OTS 44 formed similarly to a star. It is conceivable that low-mass planets could arise in the disk around OTS 44 and that OTS 44 represents a mini-planetary system.

Web links

Commons : OTS 44  - collection of images, videos and audio files

Individual evidence

  1. ↑ 2MASS J11100934-7632178 - Brown Dwarf (M <0.08solMass). In: SIMBAD . Retrieved July 1, 2018 .
  2. ↑ a b c d K. L. Luhman, Paola D'Alessio, Nuria Calvet, Lori E. Allen, Lee Hartmann, ST Megeath, PC Myers, GG Fazio: Spitzer Identification of the Least Massive Known Brown Dwarf with a Circumstellar Disk . In: The Astrophysical Journal . 620, No. 1, February 2005, pp. L51-L54. arxiv : astro-ph / 0502100 . bibcode : 2005ApJ ... 620L..51L . doi : 10.1086 / 428613 .
  3. ↑ a b c d e V. Joergens, M. Bonnefoy, Y. Liu, A. Bayo, S. Wolf, G. Chauvin, P. Rojo: OTS 44: Disk and accretion at the planetary border . In: Astronomy & Astrophysics . 558, No. 7, 2013. doi : 10.1051 / 0004-6361 / 201322432 .
  4. ↑ a b M. Bonnefoy, G. Chauvin, A.-M. Lagrange, P. Rojo, F. Allard, C. Pinte, C. Dumas, D. Homeier: A library of near-infrared integral field spectra of young ML dwarfs . In: Astronomy & Astrophysics . 562, No. 127, 2014. doi : 10.1051 / 0004-6361 / 201118270 .
  5. ^ KL Luhman, DE Peterson, ST Megeath: Spectroscopic Confirmation of the Least Massive Known Brown Dwarf in Chamaeleon . In: The Astrophysical Journal . 617, No. 1, 2004. doi : 10.1086 / 425228 .
  6. ↑ M. Tamura, Y. Itoh, Y. Oasa, T. Nakajima: Isolated and Companion Young Brown Dwarfs in the Taurus and Chamaeleon Molecular Clouds . In: Science . 282, No. 5391, 1998, p. 1095. doi : 10.1126 / science.282.5391.1095 .
  7. ↑ Y. Oasa, M. Tamura, K. Sugitani: A Deep Near-Infrared Survey of the Chamaeleon I dark cloud core . In: The Astrophysical Journal . 526, No. 1, 1999, pp. 336-343. doi : 10.1086 / 307964 .