Astronomy:Gliese 393
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Sextans |
| Right ascension | 10h 28m 55.551s[1] |
| Declination | +00° 50′ 27.60″[1] |
| Apparent magnitude (V) | 9.65[2] |
| Characteristics | |
| Spectral type | M2V[3] |
| U−B color index | 1.192[2] |
| B−V color index | 1.507±0.014[2] |
| Astrometry | |
| Radial velocity (Rv) | +8.34±0.10[2] km/s |
| Proper motion (μ) | RA: −602.992[1] mas/yr Dec.: −731.882[1] mas/yr |
| Parallax (π) | 142.0951 ± 0.0212[1] mas |
| Distance | 22.953 ± 0.003 ly (7.038 ± 0.001 pc) |
| Absolute magnitude (MV) | 10.40[2] |
| Details[3] | |
| Mass | 0.432±0.011 M☉ |
| Radius | 0.4459±0.0073 R☉ |
| Luminosity | 0.02687±0.00054 L☉ |
| Surface gravity (log g) | 4.88±0.07 cgs |
| Temperature | 3,579±51 K |
| Metallicity [Fe/H] | −0.09±0.16 dex |
| Rotation | 34.15±0.22 d[4] |
| Rotational velocity (v sin i) | 1.5[5] km/s |
| Age | 3.28[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gliese 393, or GJ 393, is a single[7] star with an orbiting exoplanet companion in the equatorial constellation of Sextans, positioned about 1.5° to the NNW of Beta Sextantis.[8] At an apparent visual magnitude of 9.65,[2] it is much too faint to be seen with the unaided eye. This star is located at a distance of 22.9 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +8.3 km/s.[2] It has a large proper motion, traversing the celestial sphere at the rate of 0.950″ per year.[9] The net velocity of this star relative to the Sun is 32.9 km/s.[2] It shares a similar space motion as members of the AB Doradus moving group, but is considered a random interloper.[5]
The stellar classification of GJ 393 is M2V,[3] indicating this is a small red dwarf star that is generating energy through core hydrogen fusion. It is rotating slowly and appears to be chromospherically inactive, suggesting it is an older star; perhaps as much as 10 billion years old.[5] The star has 43% of the mass of the Sun and 44.6% of the Sun's radius. The metallicity, what astronomers term the abundance of heavy elements, is lower than in the Sun. It is radiating just 2.7% of the Sun's luminosity from its photosphere at an effective temperature of 3,579 K.[3]
Planetary system
In 2019, one candidate planet was detected by the radial velocity method. It is classified as a hot super-Earth, with an orbital period of one week and a semimajor axis of 8.2 Gm. Longer period signals found in the data were interpreted as stellar activity.[10]
In 2021, the planet was confirmed as real after being detected independently in three different datasets.[11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.71±0.24 M⊕ | 0.05402±0.00072 | 7.0268±0.00082 | 0 | — | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A
- ↑ 3.0 3.1 3.2 3.3 Schweitzer, A. et al. (May 2019). "The CARMENES search for exoplanets around M dwarfs. Different roads to radii and masses of the target stars". Astronomy & Astrophysics 625: 16. doi:10.1051/0004-6361/201834965. A68. Bibcode: 2019A&A...625A..68S.
- ↑ 4.0 4.1 Engle, Scott G.; Guinan, Edward F. (September 2023). "Living with a Red Dwarf: The Rotation-Age Relationships of M Dwarfs". The Astrophysical Journal Letters 954 (2): L50. doi:10.3847/2041-8213/acf472. L50. Bibcode: 2023ApJ...954L..50E.
- ↑ 5.0 5.1 5.2 Schaefer, G. H. et al. (May 2018), "AB Dor Moving Group Stars Resolved with the CHARA Array", The Astrophysical Journal 858 (2): 14, doi:10.3847/1538-4357/aaba71, 71, Bibcode: 2018ApJ...858...71S
- ↑ "GJ 393". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=GJ+393.
- ↑ Winters, Jennifer G. et al. (June 2019). "The Solar Neighborhood. XLV. The Stellar Multiplicity Rate of M Dwarfs Within 25 pc". The Astronomical Journal 157 (6): 32. doi:10.3847/1538-3881/ab05dc. 216. Bibcode: 2019AJ....157..216W.
- ↑ Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. 2. Sky Publishing Corporation and the European Space Agency. p. 779. ISBN 0-933346-83-2.
- ↑ Lépine, Sébastien; Shara, Michael M. (March 2005). "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)". The Astronomical Journal 129 (3): 1483–1522. doi:10.1086/427854. Bibcode: 2005AJ....129.1483L.
- ↑ 10.0 10.1 Barnes, J. R.; et al. (2019-06-11). "Frequency of planets orbiting M dwarfs in the Solar neighbourhood". arXiv:1906.04644 [astro-ph.EP].
- ↑ 11.0 11.1 Amado, Pedro J. et al. (2021-05-28). "The CARMENES search for exoplanets around M dwarfs". Astronomy & Astrophysics 650: A188. doi:10.1051/0004-6361/202140633.
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