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2MASS J10475385+2124234

Coordinates: Sky map 10h 47m 53.85s, +21° 24′ 29.8″
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2MASS J10475385+2124234
Observation data
Epoch J2000      Equinox J2000
Constellation Leo
Right ascension 10h 47m 53.85456s[1]
Declination 21° 24′ 23.4684″[1]
Characteristics
Spectral type T6.5
Apparent magnitude (J) 15.819 ± 0.059[1]
Apparent magnitude (H) 15.797 ± 0.120[1]
Apparent magnitude (K) 16.20 ± 0.03[1]
Astrometry
Proper motion (μ) RA: −1714 mas/yr[2]
Dec.: −489 mas/yr[2]
Parallax (π)94.73±3.81 mas[3]
Distance34 ± 1 ly
(10.6 ± 0.4 pc)
Details
Mass42±26[4] MJup
Radius0.94 ± 0.16[4] RJup
Luminosity4.35×10−6[5] L☉
Surface gravity (log g)4.96 ± 0.49[4] cgs
Temperature880 ± 76[6] K
Rotation1.77 ± 0.04 h[6]
Other designations
2MASSW J1047539+212423[1]
2MASSI J1047539+212423[1]
2MASSI J1047538+212423[1]
WISEA J104752.35+212417.2[1]
Database references
SIMBADdata

2MASS J10475385+2124234 (abbreviated to 2MASS J1047+21) is a brown dwarf of spectral class T6.5, in the constellation Leo. This object lies at a distance of 34 light-years from Earth. It first attracted attention by becoming the first brown dwarf of spectral class T from which radio waves were detected. This discovery then permitted its wind speeds to be computed.

Discovery

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2MASS J1047+21 was discovered in 1999 along with eight other brown dwarf candidates during the Two Micron All-Sky Survey (2MASS), conducted from 1997 to 2001. Follow-up observations with the Keck I 10-meter telescope's Near Infrared Camera (NIRC) were conducted on 27 May 1999 and identified methane in 2MASS J1047+21's near-infrared spectrum, classifying it as a T-type brown dwarf.[7]

Detection of radio emissions

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In 2010, astronomers using the Arecibo radio telescope discovered bursts of low-frequency radio waves coming from 2MASS J1047+21. This radio emission comes from electrons spiraling around the magnetic field lines of the brown dwarf.[8][9] Since the frequency of the radio emission is linked to the strength of the magnetic field, the team measured a magnetic field strength of 1.7 kG. The bursts were also found to drift in frequency, in a manner reminiscent of certain types of solar radio emission. The radio emissions, together with the detection of Hα, which is usually found in stellar chromospheres, shows that 2MASS J1047+21 is magnetically active.

Measurement of wind speed

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The wind speed is directly inferred from minute, regular cycles in its visible (which matches its ultra-violet) appearance compared to the same at radio wave spectra.[10][11][12][13] The radio emissions are coming from electrons interacting with the magnetic field, which is rooted deep in the interior.[12] The visible and infrared (IR) data, on the other hand, reveal what's happening in the gas giant's cloud tops.[12]

Characteristics

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Artist's impression of a brown dwarf and its magnetic field

Radio emissions imply a magnetic field strength greater than 1.7 kG, or approximately 3000 times stronger than the Earth's magnetic field.[14]

Wind speeds

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Artist's concept of the interior structure of a brown dwarf. The magnetic field rotates at a different rate than the top of the atmosphere.

Wind speeds on 2MASS J1047+21 were measured to be 650 ± 310 metres per second (1,450 ± 690 mph) by the Spitzer Space Telescope.[6][15][16]

See also

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other T-dwarfs with radio emission:

References

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  1. ^ a b c d e f g h i "2MASSW J1047539+212423 -- Brown Dwarf (M<0.08solMass)". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 May 2020.
  2. ^ . Bibcode:2009AJ....137....1F. {{cite journal}}: Cite journal requires |journal= (help); Missing or empty |title= (help)
  3. ^ . Bibcode:2012ApJ...752...56F. {{cite journal}}: Cite journal requires |journal= (help); Missing or empty |title= (help)
  4. ^ a b c Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. (September 2015). "Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime". The Astrophysical Journal. 810 (2): 46. arXiv:1508.01767. Bibcode:2015ApJ...810..158F. doi:10.1088/0004-637X/810/2/158. S2CID 89611607. 158.
  5. ^ Williams, Peter K. G.; Berger, Edo; Zauderer, B. Ashley (April 2013). "Quasi-quiescent Radio Emission from the First Radio-emitting T Dwarf". The Astrophysical Journal Letters. 767 (2): 6. arXiv:1301.2321. Bibcode:2013ApJ...767L..30W. doi:10.1088/2041-8205/767/2/L30. S2CID 119117469. L30.
  6. ^ a b c Allers, Katelyn N.; Vos, Johanna M.; Biller, Beth A.; Williams, Peter K. G. (10 April 2020). "A measurement of the wind speed on a brown dwarf" (PDF). Science. 368 (6487): 169–172. Bibcode:2020Sci...368..169A. doi:10.1126/science.aaz2856. hdl:20.500.11820/06e2e379-467a-456f-956c-b37912b8d95a. PMID 32273464. S2CID 215551310.
  7. ^ Burgasser, Adam J.; Kirkpatrick, J. Davy; Brown, Michael E.; Reid, I. Neill; Gizis, John E.; Dahn, Conard C.; et al. (September 1999). "Discovery of Four Field Methane (T-Type) Dwarfs with the Two Micron All-Sky Survey". The Astrophysical Journal. 522 (1): L65 – L68. arXiv:astro-ph/9907019. Bibcode:1999ApJ...522L..65B. doi:10.1086/312221. S2CID 15326092.
  8. ^ Phys.org. "Record-breaking radio waves discovered from ultra-cool star" (Press release).
  9. ^ Route, M.; Wolszczan, A. (10 March 2012). "The Arecibo Detection of the Coolest Radio-flaring Brown Dwarf". The Astrophysical Journal Letters. 747 (2): L22. arXiv:1202.1287. Bibcode:2012ApJ...747L..22R. doi:10.1088/2041-8205/747/2/L22. S2CID 119290950.
  10. ^ Finley, Dave (9 April 2020). "Astronomers Measure Wind Speed on a Brown Dwarf". National Radio Astronomy Observatory. Retrieved 23 May 2020.
  11. ^ Cofield, Calla (9 April 2020). "In a First, NASA Measures Wind Speed on a Brown Dwarf". Jet Propulsion Laboratory. NASA. Retrieved 23 May 2020.
  12. ^ a b c Wall, Mike (9 April 2020). "How the brown dwarf blows: Wind speed of a 'failed star' measured for 1st time". Space.com. Retrieved 23 May 2020.
  13. ^ Anderson, Paul Scott (15 April 2020). "First-ever measure of brown dwarf wind speed". EarthSky. Retrieved 23 May 2020.
  14. ^ Route, M.; Wolszczan, A. (10 March 2012). "The Arecibo Detection of the Coolest Radio-flaring Brown Dwarf". The Astrophysical Journal Letters. 747 (2): L22. arXiv:1202.1287. Bibcode:2012ApJ...747L..22R. doi:10.1088/2041-8205/747/2/L22. S2CID 119290950.
  15. ^ Allers, Katelyn; Vos, Johanna; Biller, Beth; Williams, Peter; Berger, Edo (August 2016). "Wind speeds on extrasolar worlds". Spitzer Proposal. Infrared Science Archive: 13031. Bibcode:2016sptz.prop13031A.
  16. ^ Allers, Katelyn; Vos, Johanna; Biller, Beth; Williams, Peter (October 2017). "Measuring the wind speed on a radio-emitting brown dwarf". Spitzer Proposal. Infrared Science Archive: 13231. Bibcode:2017sptz.prop13231A.
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