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 is classified as a Beta Lyrae variable with a period roughly of 0.4628 days.[3]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Andromeda |
Right ascension | 00h 20m 30.54209s[2] |
Declination | +40° 13′ 33.80342″[2] |
Apparent magnitude (V) | 9.62 – 10.21 variable [3] |
Characteristics | |
Spectral type | F5V[3] |
Apparent magnitude (B) | 10.24[4] |
Apparent magnitude (V) | 9.706[4] |
Apparent magnitude (G) | 9.6637[2] |
Apparent magnitude (J) | 8.670[5] |
Apparent magnitude (H) | 8.452[5] |
Apparent magnitude (K) | 8.427[5] |
B−V color index | 0.49725[4] |
Variable type | EB[3] |
Astrometry | |
Radial velocity (Rv) | −24.2±1.0[6] km/s |
Proper motion (μ) | RA: −8.549±0.054 [2] mas/yr Dec.: −35.291±0.024[2] mas/yr |
Parallax (π) | 4.9670 ± 0.0425 mas[2] |
Distance | 657 ± 6 ly (201 ± 2 pc) |
Orbit[6] | |
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[7] M☉ |
Radius | 1.48±0.03[7] R☉ |
Luminosity | 3.40[7] L☉ |
Surface gravity (log g) | 4.24[6] cgs |
Temperature | 6,450[7] K |
Secondary | |
Mass | 0.552±0.020[7] M☉ |
Radius | 0.95[7] R☉ |
Luminosity | 0.40[7] L☉ |
Surface gravity (log g) | 4.22[6] cgs |
Temperature | 4,726[7] K |
Other designations | |
Database references | |
SIMBAD | data |
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,[7] and there is a mass flow from the primary star to the secondary at a rate of 1.4 × 10−7 M☉ yr−1.[6] The binary orbit is slowly decaying at rate 1.5*10−7 days/year. The third suspected component of the system is the red dwarf star with mass about 0.11 M☉, at 38±4 years orbit around binary. [8]
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.[3] 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 other.[6]