Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Octans |
Right ascension | 21h 25m 27.4899s[2] |
Declination | −81° 38′ 27.673″[2] |
Apparent magnitude (V) | 11.5 - 12.0[3] |
Characteristics | |
Spectral type | M1 V[4] |
Variable type | BY Dra[3] |
Astrometry | |
Radial velocity (Rv) | 8.7±4.6[4] km/s |
Proper motion (μ) | RA: 59.843 mas/yr Dec.: −107.723 mas/yr |
Parallax (π) | 29.2836 ± 0.0690 mas[5] |
Distance | 111.4 ± 0.3 ly (34.15 ± 0.08 pc) |
Details | |
Mass | 0.53[6] M☉ |
Radius | 0.46[7] R☉ |
Luminosity | 0.032[7] L☉ |
Surface gravity (log g) | 4.3[8] cgs |
Temperature | 3,490[9] K |
Metallicity [Fe/H] | −1.3[8] dex |
Rotation | 0.541945[3] days |
Rotational velocity (v sin i) | 43.5±1.2[9] km/s |
Age | 10-45[9] Myr |
Other designations | |
2MASS J21252752-8138278, FT Octantis | |
Database references | |
SIMBAD | data |
TYC 9486-927-1 (also known as 2MASS J21252752-8138278) is the primary of a possible trinary star system located at a distance of 26.7 parsecs from Earth in the southern direction in the constellation of Octans. It is a BY Draconis variable, with large starspots causing it to change brightness as it rotates every 13 hours.[3]
TYC 9486-927-1 has rapid rotation and coronal and chromospheric activity suggestive of a young age. Observations and multi-epoch radial velocity data suggest that TYC 9486-927-1 is a single, rapidly rotating star rather than a spectroscopic or tight visual binary. However, it is still possible that TYC 9486-927-1 is an equal mass binary with a face-on orbit and close separation.[4]
The candidate secondary stellar companion is 2MASS J21121598–8128452. It is a red dwarf star of spectral class M5.5. Its projected separation from the primary would be 62,700 AU. The candidate tertiary companion is 2MASS J21192028–8145446 - of spectral class M6 or M7 and at a projected separation of 31,000 AU from the primary.[6]: 7
The planet 2MASS J21265040-8140293 orbits TYC 9486-927-1 at a projected separation of 7400 AU.[6] With a mass from 11.6 to 15 Jupiter masses, it is considered to be either a brown dwarf, or a giant planet.[10][11]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
2MASS J2126–8140/b | 13.3 (± 1.7)[12] MJ | 6,900[9] | 328 725 000[citation needed] | — | — | — |