2MASS 0939-2448

2MASS 0939-2448
Observation data
Epoch J2000      Equinox J2000
Constellation Antlia
Right ascension 09h 39m 35.48s
Declination −24° 48′ 27.9″
Characteristics
Spectral type T8[1]
Apparent magnitude (J) 15.61 ± 0.09[1]
Apparent magnitude (H) 15.96 ± 0.09[1]
Apparent magnitude (K) 16.83 ± 0.09[1]
Astrometry
Proper motion (μ) RA: +573.4 ± 2.3[2] mas/yr
Dec.: −1044.7 ± 2.5[2] mas/yr
Parallax (π)187.3 ± 4.6[2] mas
Distance17.4 ± 0.4 ly
(5.3 ± 0.1 pc)
Details
2MASS 0939-2448 A
Mass20 - 50[1] MJup
Radius0.08 - 0.09[1] R☉
Temperature600 - 700[1] K
Metallicity−0.3 - 0.0[1]
Age2 – 10[1] Gyr
2MASS 0939-2448 B
Mass20 - 40[1] M☉
Radius0.09[1] R☉
Temperature600 - 700[1] K
Metallicity−0.3 - 0.0[1]
Age2 – 10[1] Gyr
Other designations
2MASS J09393548-2448279[3]
Database references
SIMBADdata

2MASS 0939-2448 (full designation is 2MASS J09393548-2448279)[3] is a probable system of two nearby T-type brown dwarfs, located in constellation Antlia at 17.4 light-years from Earth.[2]

Discovery

2MASS 0939-2448 was identified as a brown dwarf through analysis of data from the 2MASS survey by Tinney et al. The discovery was published in 2005.[3]

Distance

2MASS 0939-2448 distance estimates

Source Parallax, mas Distance, pc Distance, ly Distance, Pm Ref.
Tinney et al. (2005) ~ 8 ~ 26.1 ~ 246.9 [3]
Burgasser et al. (2008) 187.3±4.6 5.34±0.13 17.4±0.4 164.7+4.1
−3.9		 [2]
RECONS TOP100 (2012) 187.3±4.6[nb 1] 5.34±0.13 17.4±0.4 164.7+4.1
−3.9		 [4]
Faherty et al. (2012) 196.0±10.4 5.1+0.29
−0.26		 16.6+0.9
−0.8		 157.4+8.8
−7.9		 [5]
Smart et al. (2013) 7±1 22.8±3.3 216±30.9 [6]
Tinney et al. (2014) 187±5[nb 2] 5.35+0.15
−0.14		 17.4±0.5 165+4.5
−4.3		 [7][2]

Non-trigonometric distance estimates are marked in italic. The most precise estimate is marked in bold.

Proper motion

2MASS 0939-2448 proper motion estimates

Source μ, mas/yr P. A., ° μRA, mas/yr μDEC, mas/yr Ref.
Tinney et al. (2005)1150 ± 60155 ± 1486 ± 44−1042 ± 63[3]
Burgasser et al. (2008)1192 ± 3151.24 ± 0.15573.4 ± 2.3−1044.7 ± 2.5[2]
Faherty et al. (2012)1172 ± 8151.6 ± 0.4558.1 ± 5.8−1030.5 ± 5.6[5]

The most accurate estimates are marked in bold. Italic are computed values, not italic are values, given in the sources.

Properties

Model calculations suggest that 2MASS 0939-2448 is a system of two brown dwarfs with effective temperatures of about 500 and 700 K and masses of about 25 and 40 Jupiter masses, it is also possible that it is a pair of identical objects with temperatures of 600 K and 30 Jupiter masses.[1]

Dimmest known brown dwarf

From publication of the discovery in 2005 till at least 2008 2MASS 0939-2448 or its dimmer component was the dimmest brown dwarf known.[8] Later dimmer objects, including (sub-)brown dwarfs and rogue planets of new spectral class Y, were discovered, using data from WISE and from other surveys. In 2011—2014 the dimmest known of these objects was WISE 1828+2650, and from 2014 the dimmest one is WISE 0855−0714.

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 Leggett, S. K.; Cushing, Michael C.; Saumon, D.; Marley, M. S.; Roellig, T. L.; Warren, S. J.; Burningham, Ben; Jones, H. R. A.; Kirkpatrick, J. D.; Lodieu, N.; Lucas, P. W.; Mainzer, A. K.; Martín, E. L.; McCaughrean, M. J.; Pinfield, D. J.; Sloan, G. C.; Smart, R. L.; Tamura, M.; Van Cleve, J. (2009). "The Physical Properties of Four ~600 K T Dwarfs". The Astrophysical Journal 695 (2): 1517–1526. arXiv:0901.4093. Bibcode:2009ApJ...695.1517L. doi:10.1088/0004-637X/695/2/1517.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Burgasser, Adam J.; Tinney, C. G.; Cushing, Michael C.; Saumon, Didier; Marley, Mark S.; Bennett, Clara S.; Kirkpatrick, J. Davy (2008). "2MASS J09393548-2448279: The Coldest and Least Luminous Brown Dwarf Binary Known?". The Astrophysical Journal 689 (1): L53–L56. Bibcode:2008ApJ...689L..53B. doi:10.1086/595747.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Tinney, C. G.; Burgasser, Adam J.; Kirkpatrick, J. Davy; McElwain, Michael W. (2005). "The 2MASS Wide-Field T Dwarf Search. IV. Hunting Out T Dwarfs with Methane Imaging". The Astronomical Journal 130 (5): 2326–2346. arXiv:astro-ph/0508150. Bibcode:2005AJ....130.2326T. doi:10.1086/491734.
  4. ↑ "RECONS TOP100". THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars). 2012.
  5. ↑ 5.0 5.1 Faherty, Jacqueline K.; Burgasser, Adam J.; Walter, Frederick M.; Van der Bliek, Nicole; Shara, Michael M.; Cruz, Kelle L.; West, Andrew A.; Vrba, Frederick J.; Anglada-Escud, Guillem (2012). "The Brown Dwarf Kinematics Project (BDKP). III. Parallaxes for 70 Ultracool Dwarfs". The Astrophysical Journal 752 (1): 56. arXiv:1203.5543. Bibcode:2012ApJ...752...56F. doi:10.1088/0004-637X/752/1/56.
  6. ↑ Smart, R. L.; Tinney, C. G.; Bucciarelli, B.; Marocco, F.; Abbas, U.; Andrei, A.; Bernardi, G.; Burningham, B.; Cardoso, C.; Costa, E.; Crosta, M. T.; Daprá, M.; Day-Jones, A.; Goldman, B.; Jones, H. R. A.; Lattanzi, M. G.; Leggett, S. K.; Lucas, P.; Mendez, R.; Penna, J. L.; Pinfield, D.; Smith, L.; Sozzetti, A.; Vecchiato, A. (2013). "NPARSEC: NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results". Monthly Notices of the Royal Astronomical Society 433 (3): 2054–2063. arXiv:1306.4527. Bibcode:2013MNRAS.433.2054S. doi:10.1093/mnras/stt876.
  7. ↑ Tinney, C. G.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Cushing, Mike; Morley, Caroline V.; Wright, Edward L. (2014). "The Luminosities of the Coldest Brown Dwarfs". The Astrophysical Journal 796 (1): 39. arXiv:1410.0746. Bibcode:2014ApJ...796...39T. doi:10.1088/0004-637X/796/1/39.
  8. ↑ "Astronomers Find the Two Dimmest Stellar Bulbs" (Press release). NASA/JPL. 2008-12-10. Retrieved 2008-12-20.

Notes

  1. ↑ According RECONS TOP100 list (2012), this parallax is from a work by Tinney. Actually it is from Burgasser et al. (2008), Tinney is one of coauthors of the article.
  2. ↑ Rounded value of parallax from Burgasser et al. (2008).

Coordinates: 09h 39m 35.48s, −24° 48′ 27.9″