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.[5] 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.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 15h 01m 08.18646s[1] |
| Declination | +22° 50′ 02.1379″[1] |
| Apparent magnitude (V) | 15.09[2] |
| Characteristics | |
| Spectral type | M9[3] |
| Astrometry | |
| Proper motion (μ) | RA: −43.120±0.111 mas/yr[1] Dec.: −65.138±0.140 mas/yr[1] |
| Parallax (π) | 93.1655 ± 0.1355 mas[1] |
| Distance | 35.01 ± 0.05 ly (10.73 ± 0.02 pc) |
| Details | |
| Mass | 0.09 M☉ |
| Radius | 0.11 R☉ |
| Luminosity | 0.00042 L☉ |
| Temperature | 2,500 K |
| Age | >1 billion years |
| Other designations | |
| Database references | |
| SIMBAD | data |
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 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 was detected by the radio astrometry method.[3]
| 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° | — |