TVLM 513-46546
Brown dwarf star in the constellation Boötes
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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.[9] 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.[10]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Boötes[1] |
| Right ascension | 15h 01m 08.18646s[2] |
| Declination | +22° 50′ 02.1379″[2] |
| Apparent magnitude (V) | 15.09[3] |
| Characteristics | |
| Evolutionary stage | Brown dwarf[4] |
| Spectral type | M9[5] |
| Astrometry | |
| Proper motion (μ) | RA: −43.120±0.111 mas/yr[2] Dec.: −65.138±0.140 mas/yr[2] |
| Parallax (π) | 93.1655±0.1355 mas[2] |
| Distance | 35.01 ± 0.05 ly (10.73 ± 0.02 pc) |
| Details | |
| Mass | 0.06–0.08[4][6] M☉ |
| Radius | 0.097 – 0.109[6] R☉ |
| Luminosity | 0.00026[6] L☉ |
| Temperature | 2242±55[7] K |
| Rotation | 1.96 h[6] |
| Rotational velocity (v sin i) | 60[6] km/s |
| Age | >400[6][5] Myr |
| Other designations | |
| 2MASS J15010818+2250020, 2MASSI J1501081+225001, 2MUCD 20596 | |
| Database references | |
| SIMBAD | data |

Planetary system
On 4 August 2020 astronomers announced the potential discovery of a Saturn-like planet TVLM 513b around this star with a period of 221±5 days, a mass of between 0.35 and 0.42 MJ, a circular orbit (e≃0), a semi-major axis of between 0.28 and 0.31 AU and an inclination angle of 71−88°. The companion would have been detected by the radio astrometry method.[5] However, the discovery awaits independent confirmation.
| 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 | — |