TVLM 513-46546

TVLM 513-46546 is an M9 ultracool dwarf at the red dwarf/brown dwarf mass boundary in the constellation Boötes. It exhibits flare star activity, which is most pronounced at radio wavelengths. The star has a mass approximately 80 times the mass of Jupiter (or 8 percent of the Sun's mass). The radio emission is broadband and highly circularly polarized, similar to planetary auroral radio emissions.[4] The radio emission is periodic, with bursts emitted every 7054 s, with nearly one hundredth of a second precision. Subtle variations in the radio pulses could suggest that the ultracool dwarf rotates faster at the equator than the poles (differential rotation) in a manner similar to the Sun.[5] Nonetheless, follow-up study in 2020 has failed to find any of expected radio emmisions in 85-101 GHz band, implying the star is not magnetospherically active.[6]

TVLM 513-46546

TVLM 513-46546 (the red dot in the center), as seen by the Sloan Digital Sky Survey.
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
Right ascension 15h 01m 08.187s[1]
Declination +22° 50′ 02.12″[1]
Apparent magnitude (V) 15.09[2]
Characteristics
Spectral type M9[3]
Astrometry
Proper motion (μ) RA: -43.766 ± 0.349[1] mas/yr
Dec.: -63.997 ± 0.329[1] mas/yr
Parallax (π)93.4497 ± 0.1945[1] mas
Distance34.90 ± 0.07 ly
(10.70 ± 0.02 pc)
Details
Mass0.09 M☉
Radius0.11 R☉
Luminosity0.00042 L☉
Temperature2,500 K
Age>1 billion years
Other designations
2MASS J15010818+2250020, 2MASSI J1501081+225001, 2MUCD 20596.
Database references
SIMBADdata

Planetary system

On 4 August 2020 astronomers announced the discovery of a Saturn-like planet TVLM 513b around this star with a period of 221±5 days, a mass of between 0.35−0.42 MJ, a circular orbit (e≃0), a semi-major axis of between 0.28−0.31 AU and an inclination angle of 71−88∘. The companion was detected by the radio astrometry method.[3]

The TVLM 513-46546 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b 0.35−0.42 MJ 0.28−0.31 221 ± 5 0 71−88∘° —

References
  1. Gaia Collaboration (2018-08-01). "Gaia Data Release 2 - Summary of the contents and survey properties". Astronomy & Astrophysics. 616: A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. ISSN 0004-6361. S2CID 49211658.
  2. "TVLM 513-46". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-08-22.
  3. Curiel, Salvador; Ortiz-León, Gisela N.; Mioduszewski, Amy J.; Torres, Rosa M. (2020). "An Astrometric Planetary Companion Candidate to the M9 Dwarf TVLM 513–46546". The Astronomical Journal. 160 (3): 97. arXiv:2008.01595. Bibcode:2020AJ....160...97C. doi:10.3847/1538-3881/ab9e6e. S2CID 220961489.
  4. Hallinan, G. (2006). "Rotational Modulation of the Radio Emission from the M9 Dwarf TVLM 513-46546: Broadband Coherent Emission at the Substellar Boundary?". The Astrophysical Journal. 653 (1): 690–699. arXiv:astro-ph/0608556. Bibcode:2006ApJ...653..690H. doi:10.1086/508678. S2CID 118885768.
  5. Wolszczan, A.; Route, M. (2014). "Timing Analysis of the Periodic Radio and Optical Brightness Variations of the Ultracool Dwarf, TVLM 513-46546". The Astrophysical Journal. 788 (1): 23. arXiv:1404.4682. Bibcode:2014ApJ...788...23W. doi:10.1088/0004-637X/788/1/23. S2CID 119114679.
  6. A search for millimeter emission from the coldest and closest brown dwarf with ALMA, 2020, arXiv:2009.05414


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.