RT Andromedae
 RT Andromedae system. | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 11m 10.099s[1] |
| Declination | +53° 01′ 33.04″[1] |
| Apparent magnitude (V) | 9.043[2] |
| Characteristics | |
| Spectral type | G0V / K2V[3] |
| Variable type | RS CVn |
| Astrometry | |
| Proper motion (μ) | RA: -7.01[1] mas/yr Dec.: -20.80[1] mas/yr |
| Parallax (π) | 10.05 ± 0.22 mas |
| Distance | 270.7 ± 6.5 ly (83 ± 2[3] pc) |
| Absolute bolometric magnitude (Mbol) | 5.707 / 4.079[4] |
| Orbit[5] | |
| Period (P) | 0.62893095 ± 0.00000009 d |
| Semi-major axis (a) | 0.01635 AU |
| Eccentricity (e) | 0.31 ± 0.05 |
| Inclination (i) | 87.6 ± 0.1[3]° |
| Periastron epoch (T) | JD 2435454.4554 ± 0.0009 |
| Argument of periastron (ω) (secondary) | 306 ± 15° |
| Details | |
| RT And A | |
| Mass | 1.088 ± 0.030[4] M☉ |
| Radius | 1.286 ± 0.011[4] R☉ |
| RT And B | |
| Mass | 0.837 ± 0.030[4] M☉ |
| Radius | 0.956 ± 0.012[4] R☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
RT Andromedae is a variable star in the constellation of Andromeda. The system is estimated to be 270.7 light-years (83 parsecs) away.[3]
RT Andromedae is classified as a RS Canum Venaticorum variable, a type of close eclipsing binary star. It varies from an apparent visual magnitude of 9.83 at minimum brightness to a magnitude of 8.97 at maximum brightness, with a period of 0.6289216 days.[6] The system consists of a G-type main-sequence star slightly more massive than the Sun, and a K-type main-sequence star.[3]
Presence of a third body
According to Pribulla et al. (2000), a third object could be present in the system. Its minimum mass is estimated to be 5 percent the mass of the Sun (roughly 50 times the mass of Jupiter), with an orbital period close to 75 years and an eccentricity that is thought to be fairly high (at 0.56).[3] Such an object could likely turn out to be a brown dwarf or even a massive jovian planet. However, a recent paper of Manzoori (2009) states that the minimum mass of the third body is likely to be close to 0.6 Solar masses, making the object stellar rather than substellar.[4] Also, the orbital period has turned out to be more than 85 years.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (retracted) | — | — | 27000 ± 3700 | 0.56 ± 0.13 | — | — |
References
- 1 2 3 4 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. Bibcode:2007A&A...474..653V. arXiv:0708.1752
. doi:10.1051/0004-6361:20078357. Vizier catalog entry - ↑ Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- 1 2 3 4 5 6 7 Pribulla; et al. (2000). "Active eclipsing binary RT Andromedae revisited". Astronomy & Astrophysics. 362: 169–188. Bibcode:2000A&A...362..169P.
- 1 2 3 4 5 6 Manzoori, D. (2009). "Cyclic Variations of Orbital Period and Long-Term Luminosity in Close Binary RT Andromedae". The Astronomical Journal. 138 (6): 1917–1924. Bibcode:2009AJ....138.1917M. doi:10.1088/0004-6256/138/6/1917.
- ↑ Erdem, A.; Demircan, O.; Güre, M. (2001). "The light and period changes of RT Andromedae". Astronomy & Astrophysics. 379 (3): 878. Bibcode:2001A&A...379..878E. doi:10.1051/0004-6361:20011357.
- ↑ RT And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2009-06-22.