CN Andromedae
CN Andromedae (CN And) is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.62 and drops down to a minimum of 10.2 during the main eclipse. It's classified as a Beta Lyrae variable with a period roughly of 0.4628 days.[2]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Andromeda |
Right ascension | 00h 20m 30.54209s[1] |
Declination | +40° 13′ 33.80342″[1] |
Apparent magnitude (V) | 9.62 – 10.21 variable [2] |
Characteristics | |
Spectral type | F5V[2] |
Apparent magnitude (B) | 10.24[3] |
Apparent magnitude (V) | 9.706[3] |
Apparent magnitude (G) | 9.6637[1] |
Apparent magnitude (J) | 8.670[4] |
Apparent magnitude (H) | 8.452[4] |
Apparent magnitude (K) | 8.427[4] |
B−V color index | 0.49725[3] |
Variable type | EB[2] |
Astrometry | |
Radial velocity (Rv) | −24.2±1.0[5] km/s |
Proper motion (μ) | RA: −8.549±0.054 [1] mas/yr Dec.: −35.291±0.024[1] mas/yr |
Parallax (π) | 4.9670 ± 0.0425[1] mas |
Distance | 657 ± 6 ly (201 ± 2 pc) |
Orbit[5] | |
Period (P) | 0.4627952±0.000035 days |
Semi-major axis (a) | 3.066±0.035 |
Inclination (i) | 68.51±0.17° |
Periastron epoch (T) | HJD 2445231.51710±0.00059 |
Details | |
Primary | |
Mass | 1.433±0.030[6] M☉ |
Radius | 1.48±0.03[6] R☉ |
Luminosity | 3.40[6] L☉ |
Surface gravity (log g) | 4.24[5] cgs |
Temperature | 6,450[6] K |
Secondary | |
Mass | 0.552±0.020[6] M☉ |
Radius | 0.95[6] R☉ |
Luminosity | 0.40[6] L☉ |
Surface gravity (log g) | 4.22[5] cgs |
Temperature | 4,726[6] K |
Other designations | |
Database references | |
SIMBAD | data |
System
The two stars in this system orbit very close to each other; their spectrum cannot be separated and as a whole they have a spectrum of an F5V star. They are in marginal contact,[6] and there is a mass flow from the primary star to the secondary at a rate of 1.4 × 10−7 M☉ yr−1.[5]
Variability
The light curve of CN Andromedae shows a primary eclipse, with its brightness dropping down to 10.21 magnitude, and a secondary one down to a magnitude of 9.9.[2] This phenomenon repeats with a cycle of approximately 11.1 hours, with period decreasing in time due to the mass transfer from one star to the another.[5]
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- CN 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 2018-10-17.
- Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy & Astrophysics, 355: L27–L30, Bibcode:2000A&A...355L..27H.
- Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; et al. (June 2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues (2246): II/246. Bibcode:2003yCat.2246....0C.
- Van Hamme, W.; Samec, R. G.; Gothard, N. W.; Wilson, R. E.; Faulkner, D. R.; Branly, R. M. (2001). "CN Andromedae: A Broken-Contact Binary?". The Astronomical Journal. 122 (6): 3436–3446. Bibcode:2001AJ....122.3436V. doi:10.1086/324110.
- Siwak, M.; Zola, S.; Koziel-Wierzbowska, D. (2010). "A Study of Contact Binaries with Large Temperature Differences between Components". Acta Astronomica. 60 (4): 305–336. Bibcode:2010AcA....60..305S.