Wikipedia

2MASS J10475385 2124234

2MASS J10475385 2124234 (abbreviated to 2MASS J1047 21) is a brown dwarf of spectral class T6.5, in the constellation Leo about 34 light-years from Earth, hence in galactic topographical and interstellar medium study terms being in the Local Bubble and very nearby in the Orion Arm. The object 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.

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[1] mas/yr
Dec.: -489[1] mas/yr
Parallax (π)94.73 ± 3.81 mas
Distance34 ± 1 ly
(10.6 ± 0.4 pc)
Details
Mass41.61 ± 26.03[2] MJup
Radius0.94 ± 0.16[2] RJup
Luminosity0.000004365[3] L☉
Surface gravity (log g)4.96 ± 0.49[2] cgs
Temperature880 ± 76[4] K
Rotation1.77 ± 0.04 h[4]
Age0.5–10[2] Gyr
Other designations
2MASSW J1047539 212423[1]
2MASSI J1047539 212423[1]
2MASSI J1047538 212423[1]
WISEA J104752.35 212417.2[1]
Database references
SIMBADdata

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.[5]

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.[6][7] 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.[8][9][10][11] The radio emissions are coming from electrons interacting with the magnetic field, which is rooted deep in the interior.[10] The visible and infrared (IR) data, on the other hand, reveal what's happening in the gas giant's cloud tops.[10]


Characteristics

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

2MASS J1047 21 is a T-type brown dwarf.[5]

Distance

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2MASS J1047 21 is about 34 light-years (10 pc) from Earth.[4]

Magnetic Field

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Radio emissions imply a magnetic field strength greater than 1.7 kG, or approximately 3000 times stronger than the Earth's magnetic field.[12]

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.[4][13][14]


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 j k "2MASSW J1047539 212423 -- Brown Dwarf (M<0.08solMass)". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 May 2020.
  2. ^ a b c d 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.
  3. ^ 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.
  4. ^ a b c d 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.
  5. ^ a b 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.
  6. ^ Phys.org. "Record-breaking radio waves discovered from ultra-cool star" (Press release).
  7. ^ 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.
  8. ^ Finley, Dave (9 April 2020). "Astronomers Measure Wind Speed on a Brown Dwarf". National Radio Astronomy Observatory. Retrieved 23 May 2020.
  9. ^ Cofield, Calla (9 April 2020). "In a First, NASA Measures Wind Speed on a Brown Dwarf". Jet Propulsion Laboratory. NASA. Retrieved 23 May 2020.
  10. ^ 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.
  11. ^ Anderson, Paul Scott (15 April 2020). "First-ever measure of brown dwarf wind speed". EarthSky. Retrieved 23 May 2020.
  12. ^ 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.
  13. ^ 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.
  14. ^ 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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