Gliese 22
Gliese 22, also catalogued V547 Cassiopeiae or ADS 440, is a hierarchical star system approximately 33 light-years away in the constellation of Cassiopeia. The system consists of pair of red dwarf stars, Gliese 22A and Gliese 22C, orbited by Gliese 22B in an outer orbit of about 320 years.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia |
| Gliese 22 A | |
| Right ascension | 00h 32m 29.4336s |
| Declination | +67° 14′ 08.409″ |
| Apparent magnitude (V) | 10.29 |
| Gliese 22 B | |
| Right ascension | 00h 32m 29.575s |
| Declination | +67° 14′ 04.63″ |
| Apparent magnitude (V) | 12.19 |
| Gliese 22 C | |
| Right ascension | 00h 32m 29.4s |
| Declination | +67° 14′ 08″ |
| Apparent magnitude (V) | 13.2 |
| Characteristics | |
| Spectral type | M2.5Ve / M3V |
| U−B color index | 1.16 |
| B−V color index | 1.54 |
| R−I color index | 0.99 |
| Variable type | Flare stars |
| Astrometry | |
| Radial velocity (Rv) | 10 km/s |
| Proper motion (μ) | RA: 1739.0 mas/yr Dec.: -224.93 mas/yr |
| Parallax (π) | 99.35 ± 2.17[1] mas |
| Distance | 32.8 ± 0.7 ly (10.1 ± 0.2 pc) |
| Absolute magnitude (MV) | 11.83 |
| Orbit | |
| Primary | Gliese 22 AC |
| Companion | Gliese 22 B |
| Period (P) | 320 yr |
| Semi-major axis (a) | 4″ |
| Inclination (i) | 140° |
| Orbit[2] | |
| Primary | Gliese 22 A |
| Companion | Gliese 22 C |
| Period (P) | 16.12±0.20 yr |
| Semi-major axis (a) | 0.529±0.005″ |
| Eccentricity (e) | 0.18±0.03 |
| Inclination (i) | 46±1° |
| Details[3] | |
| Mass | = 0.378(A) + 0.136(C) M☉ |
| Radius | 0.5(A) R☉ |
| Luminosity | 0.04 L☉ |
| Temperature | 2000–3500 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
Planetary system
As of 2008, it was announced that a possible extrasolar planet, Gliese 22B b, or brown dwarf orbits Gliese 22B but this is currently unconfirmed. The study in 2011 has indicated the orbit of the purported planet is stable.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | 16 MJ | — | 5,500 | 0 | — | — |
References
- van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
- Woitas, J.; Tamazian, V. S.; Docobo, J. A.; Leinert, Ch. (2003), "Visual orbit for the low-mass binary Gliese 22 AC from speckle interferometry", Astronomy & Astrophysics, 406: 293–298, arXiv:astro-ph/0305330, Bibcode:2003A&A...406..293W, doi:10.1051/0004-6361:20030756, S2CID 12279366
- The low-mass companion of gliese 22A: First results of the steward observatory infrared speckle camera
- ON THE DYNAMICAL STABILITY OF THE VERY LOW-MASS OBJECT GLIESE 22 BB
External links
- "Descoberta de novo planeta gigante extrasolar". Universia (in Spanish). 2008-03-16. Retrieved 2008-08-10.
- "Notes for star Gliese 22 B". The Extrasolar Planets Encyclopaedia. Retrieved 2008-08-10.
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