Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Octans |
Right ascension | 21h 25m 27.4805s [2] |
Declination | −81° 38′ 27.692″ [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: 60.645(46) mas/yr [2] Dec.: −107.740(48) mas/yr [2] |
Parallax (π) | 29.0266 ± 0.0401 mas [2] |
Distance | 112.4 ± 0.2 ly (34.45 ± 0.05 pc) |
Details | |
Mass | 0.53 [5] M☉ |
Radius | 0.46 [6] R☉ |
Luminosity | 0.032 [6] L☉ |
Surface gravity (log g) | 4.3 [7] cgs |
Temperature | 3,490 [8] K |
Metallicity [Fe/H] | −1.3 [7] dex |
Rotation | 0.541945 [3] days |
Rotational velocity (v sin i) | 43.5±1.2 [8] km/s |
Age | 10-45 [8] 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 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. [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. [5] : 7
The planet 2MASS J21265040-8140293 orbits TYC 9486-927-1 at a projected separation of 7400 AU. [5] With a mass from 11.6 to 15 Jupiter masses, it is considered to be either a brown dwarf, or a giant planet. [9] [10]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
2MASS J2126–8140/b | 13.3 (± 1.7) [11] MJ | 6,900 [8] | 328 725 000[ citation needed ] | — | — | — |
HD 142 is a wide binary star system in the southern constellation of Phoenix. The main component has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.7. The system is located at a distance of 85.5 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +6 km/s.
Gliese 105 is a triple star system in the constellation of Cetus. It is located relatively near the Sun at a distance of 23.6 light-years. Despite this, even the brightest component is barely visible with the unaided eye (see Bortle scale). No planets have yet been detected around any of the stars in this system.
HD 142022 is a binary star system located in the southernmost constellation of Octans. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.70. The distance to this system is 112 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −10 km/s.
Gliese 445 is an M-type main sequence star in the northern part of the constellation Camelopardalis.
HAT-P-4 is a wide binary star consisting of a pair of G-type main-sequence stars in the constellation of Boötes. It is also designated BD+36°2593.
XO-3 is a star in the constellation Camelopardalis. The star has a magnitude of 10 and is not visible to the naked eye but is visible through a small telescope. A search for a binary companion star using adaptive optics at the MMT Observatory was negative.
Gliese 433 is a dim red dwarf star with multiple exoplanetary companions, located in the equatorial constellation of Hydra. The system is located at a distance of 29.6 light-years from the Sun based on parallax measurements, and it is receding with a radial velocity of +18 km/s. Based on its motion through space, this is an old disk star. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 9.81 and an absolute magnitude of 10.07.
HD 9578 is a candidate wide binary star system located at a distance of approximately 183 light-years from the Sun in the southern constellation of Sculptor. The main star must be viewed with binoculars or a telescope, as its low apparent visual magnitude of 8.35 is too faint to be viewed with the naked eye. The system is drifting closer to the Sun with a radial velocity of −4 km/s.
HIP 12961 is a star with an exoplanetary companion in the equatorial constellation of Eridanus. It is too faint to be visible to the naked eye, with an apparent visual magnitude of 10.24. The distance to this system can be estimated from its parallax measurements, which yield a separation of 76.4 light-years from the Sun. It is receding with a radial velocity of +33 km/s and has a high proper motion, traversing the celestial sphere at an angular rate of 0.300″ yr−1.
2MASS J0441+2301 is a young quadruple system hosting a planetary-mass object, a red dwarf star and two brown dwarfs, approximately 470 light years away.
2MASS J15404341−5101357 is a red dwarf of spectral type M7, located in Norma at approximately 17 light-years from Earth. It is the nearest known M7 dwarf.
2MASS J18450079–1409036 and 2MASS J18450097–1409053 is a system of two red dwarf stars both of which have spectral types of M5, with projected separation of 3.2 seconds of arc. The system is located in the constellation Scutum. The Gaia parallaxes place the system at 18.2 parsecs from Earth. Kinematically, it belongs to young Argus association.
ADS 7251 is a binary star system 6.33 parsecs from the Sun. The components are near-identical red dwarfs separated by 17″ in 2019.
2MASS J19383260+4603591 is a binary star system with at least one known planet, Kepler-451b. The system comprises two stars, a pulsating subdwarf B star as well as a small red dwarf star.
2MASS J21265040−8140293, also known as 2MASS J2126−8140, is an exoplanet orbiting the red dwarf TYC 9486-927-1, 111.4±0.3 light-years away from Earth. Its estimated mass, age, spectral type (L3), and Teff are similar to the well-studied planet β Pictoris b. With an estimated distance of around 1 trillion kilometres from its host star, it is one of the largest solar systems ever found.
HD 44120 is a wide binary star system in the southern constellation of Pictor. Although visible to the naked eye, it is a challenge to view having an apparent visual magnitude of 6.44. The system is located at a distance of 118 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −2 km/s. It has an absolute magnitude of 3.57.
HD 197037 is a binary star system. Its primary or visible star, HD 197037 A, is a F-type main-sequence star. Its surface temperature is 6150±34 K. HD 197037 A is depleted in heavy elements compared to the Sun, with a metallicity Fe/H index of −0.16±0.03, but is younger at an age of 3.408±0.924 billion years.
Kepler-411 is a binary star system. Its primary star Kepler-411A is a K-type main-sequence star, orbited by the red dwarf star Kepler-411B on a wide orbit, discovered in 2012.
HD 72945 and HD 72946 form a co-moving star system in the northern constellation of Cancer. HD 72945 is a binary star that is dimly visible to the naked eye as a point of light with an apparent visual magnitude of 5.91. At an angular separation of 10.10″ is the fainter companion star HD 72946 at magnitude 7.25. It is being orbited by a brown dwarf. The system as a whole is located at a distance of approximately 84 light years from the Sun based on parallax measurements.
HR 8526, also known as HD 212168, is the primary of a triple star located in the southern circumpolar constellation Octans. The star and its companion have apparent magnitudes of 6.12 and 9.36 respectively. The system is located relatively close at a distance of 76 light years based on Gaia DR3 parallax measurements, but is receding with a heliocentric radial velocity of 15 km/s.