WISE 0855−0714

WISE 0855−0714 (full designation WISE J085510.83−071442.5,[8] or W0855 for short) is a sub-brown dwarf 2.28±0.01 parsecs (7.43±0.04 light-years)[5] from Earth, therefore the fourth-closest star or (sub-) brown dwarf system to the Sun,[1] the discovery of which was announced in April 2014 by Kevin Luhman using data from the Wide-field Infrared Survey Explorer (WISE).[1] As of 2014, WISE 0855−0714 has the third-highest proper motion (8151.6±1.8 mas/yr)[5] after Barnard's Star (10300 mas/yr) and Kapteyn's Star (8600 mas/yr)[8] and the fourth-largest parallax (439.0±2.4 mas)[5] of any known star or brown dwarf. It is also the coldest object of its type found in interstellar space, having a temperature in the range 225 to 260 K (−48 to −13 °C; −55 to 8 °F).[1]

WISE J085510.83−071442.5

Time-lapsed photo sequence of WISE 0855−0714's movement in the sky using captured images from the WISE and the Spitzer telescopes.[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Hydra
Right ascension 08h 55m 10.83s
Declination −07° 14′ 42.5″
Characteristics
Evolutionary stage Sub-brown dwarf
Spectral type Y4V[2][3]
Apparent magnitude (J) 25.00±0.53[4]
Astrometry
Proper motion (μ) RA: −8123.7±1.3[5] mas/yr
Dec.: 673.2±1.3[5] mas/yr
Parallax (π)439.0 ± 2.4 mas[5][6]
Distance7.43 ± 0.04 ly
(2.28 ± 0.01 pc)
Details
Mass~3–10 MJup
Temperature225–260 K
Other designations
WISEA J085510.74-071442.5,GJ 11286[7]
Database references
SIMBADdata
WISE 0855−0714 is located in the constellation Hydra.
WISE 0855−0714 is located in the constellation Hydra.
WISE 0855−0714
Location of WISE 0855−0714 in the constellation Hydra

Characterization

Observations
The position of WISE 0855−0714 on a radar map among all stellar objects or stellar systems within 9 light years (ly) from the map's center, the Sun (Sol). The diamond-shapes are their positions entered according to right ascension in hours angle (indicated at the edge of the map's reference disc), and according to their declination. The second mark shows each's distance from Sol, with the concentric circles indicating the distance in steps of one ly.

The WISE object was detected in March 2013, and follow-up observations were taken by the Spitzer Space Telescope and the Gemini North telescope.[1]

Distance

Based on direct observations, WISE 0855−0714 has a large parallax, which specifically relates to its distance from the Solar System. This phenomenon results in a distance of around 7.43±0.04 light-years,[5] with a small margin of error due to the strength of the parallax effect and the clarity of observations. WISE 0855−0714 also has an exceptionally high proper motion.[5]

Spectrometry

Its luminosity in different bands of the thermal infrared in combination with its absolute magnitude—because of its known distance—was used to place it in context of different models; the best characterization of its brightness was in the W2 band of 4.6 μm at an apparent magnitude of 13.89±0.05, though it was brighter into the deeper infrared.[8] Infrared images taken with the Magellan Baade Telescope suggest evidence of water clouds.[9]

Model-derived understanding

Based on models of brown dwarfs WISE 0855−0714's is estimated to have a mass of 3 to 10 MJup.[1] This mass is in the range of a sub-brown dwarf or other planetary-mass object.

As of 2003, the International Astronomical Union considers an object with a mass above 13 MJup, capable of fusing deuterium, to be a brown dwarf. A lighter object and one orbiting another object is considered a planet.[10] However, if the distinction is based on how the object formed then it might be considered a failed star, a theory advanced for the object Cha 110913-773444.[11]

Combining its luminosity, distance, and mass it is estimated to be the coldest-known brown dwarf, with a modeled effective temperature of 225 to 260 K (−48 to −13 °C; −55 to 8 °F), depending on the model.[1]

See also

References
  1. Clavin, Whitney; Harrington, J. D. (25 April 2014). "NASA's Spitzer and WISE Telescopes Find Close, Cold Neighbor of Sun". NASA.gov. Archived from the original on 26 April 2014.
  2. Davy Kirkpatrick, J.; Gelino, Christopher R.; Faherty, Jacqueline K.; Meisner, Aaron M.; Caselden, Dan; Schneider, Adam C.; Marocco, Federico; Cayago, Alfred J.; Smart, R. L.; Eisenhardt, Peter R.; Kuchner, Marc J.; Wright, Edward L.; Cushing, Michael C.; Allers, Katelyn N.; Bardalez Gagliuffi, Daniella C.; Burgasser, Adam J.; Gagne, Jonathan; Logsdon, Sarah E.; Martin, Emily C.; Ingalls, James G.; Lowrance, Patrick J.; Abrahams, Ellianna S.; Aganze, Christian; Gerasimov, Roman; Gonzales, Eileen C.; Hsu, Chih-Chun; Kamraj, Nikita; Kiman, Rocio; Rees, Jon; et al. (2021). "The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs". The Astrophysical Journal Supplement Series. 253 (1): 7. arXiv:2011.11616. Bibcode:2021ApJS..253....7K. doi:10.3847/1538-4365/abd107. S2CID 227126954.
  3. Mamajek, Eric. "A Modern Mean Dwarf Stellar Color and Effective Temperature Sequence". Retrieved 7 February 2021.
  4. "WISEA J085510.74-071442.5". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 May 2017.
  5. Kirkpatrick, J. Davy; Gelino, Christopher R.; Faherty, Jacqueline K.; Meisner, Aaron M.; Caselden, Dan; Schneider, Adam C.; Marocco, Federico; Cayago, Alfred J.; Smart, R. L.; Eisenhardt, Peter R.; Kuchner, Marc J. (2021). "The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and y Dwarfs". The Astrophysical Journal Supplement Series. 253 (1): 7. arXiv:2011.11616. Bibcode:2021ApJS..253....7K. doi:10.3847/1538-4365/abd107. S2CID 227126954.
  6. Tinney, C., Faherty, J., Kirkpatrick, J., Cushing, M., Morley, C,. Wright, E.L., 'The luminosities of the coldest brown dwarfs.' Astrophysics Journal, 796, 39 (2014/November-3)
  7. Golovin, Alex; Reffert, Sabine; Just, Andreas; Jordan, Stefan; Vani, Akash; Jahreiß, Hartmut (November 2022). "The Fifth Catalogue of Nearby Stars (CNS5)". Astronomy & Astrophysics. 670: A19. arXiv:2211.01449. Bibcode:2023A&A...670A..19G. doi:10.1051/0004-6361/202244250. Catalogue can be accessed here.
  8. Luhman, Kevin L. (21 April 2014). "Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun". The Astrophysical Journal Letters. 786 (2): L18. arXiv:1404.6501. Bibcode:2014ApJ...786L..18L. doi:10.1088/2041-8205/786/2/L18. S2CID 119102654.
  9. Faherty, Jacqueline K.; Tinney, C. G.; Skemer, Andrew; Monson, Andrew J. (August 2014). "Indications of Water Clouds in the Coldest Known Brown Dwarf". Astrophysical Journal Letters. 793 (1): L16. arXiv:1408.4671. Bibcode:2014ApJ...793L..16F. doi:10.1088/2041-8205/793/1/L16. S2CID 119246100.
  10. "Working Group on Extrasolar Planets: Definition of a "Planet"". Working Group on Extrasolar Planets of the International Astronomical Union. 28 February 2003. Archived from the original on 16 December 2014. Retrieved 28 April 2014.
  11. Papadopoulos, Leonidas (28 April 2014). "Between the Planet and the Star: A New Ultra-Cold, Sub-Stellar Object Discovered Close to Sun". AmericaSpace.com. Retrieved 28 April 2014.

Further reading
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