TYC 9486-927-1

TYC 9486-927-1

A light curve for FT Octantis, plotted from TESS data
Observation data
Epoch J2000      Equinox J2000
Constellation Octans
Right ascension 21h 25m 27.4805s
Declination −81° 38 27.692
Apparent magnitude (V) 11.5 - 12.0
Characteristics
Spectral type M1 V
Variable type BY Dra
Astrometry
Radial velocity (Rv)8.7±4.6 km/s
Proper motion (μ) RA: 60.645(46) mas/yr
Dec.: −107.740(48) mas/yr
Parallax (π)29.0266±0.0401 mas
Distance112.4 ± 0.2 ly
(34.45 ± 0.05 pc)
Details
Mass0.53 M
Radius0.46 R
Luminosity0.032 L
Surface gravity (log g)4.3 cgs
Temperature3,490 K
Metallicity [Fe/H]−1.3 dex
Rotation0.541945 days
Rotational velocity (v sin i)43.5±1.2 km/s
Age10-45 Myr
Other designations
2MASS J21252752-8138278, FT Octantis
Database references
SIMBADdata

TYC 9486-927-1 (also known as 2MASS J21252752-8138278) is the primary of a possible trinary star system located at a distance of 34.5 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.

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.

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.:7