21 Canum Venaticorum
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canes Venatici |
| Right ascension | 13h 18m 14.50953s[1] |
| Declination | +49° 40′ 55.4292″[1] |
| Apparent magnitude (V) | +5.14[2] |
| Characteristics | |
| Evolutionary stage | main sequence[1] |
| Spectral type | B9 IV (Si)[3] or A0 V Si:[4] |
| B−V color index | −0.049±0.002[2] |
| Variable type | α2 CVn[5] |
| Astrometry | |
| Radial velocity (Rv) | −2.9±2.8[2] km/s |
| Proper motion (μ) | RA: −35.161[1] mas/yr Dec.: +16.342[1] mas/yr |
| Parallax (π) | 11.6974±0.0898 mas[1] |
| Distance | 279 ± 2 ly (85.5 ± 0.7 pc) |
| Absolute magnitude (MV) | 0.48[6] |
| Details | |
| Mass | 2.73[7] M☉ |
| Radius | 2.8±0.3[6] R☉ |
| Luminosity | 72.49[2] L☉ |
| Surface gravity (log g) | 4.05[7] cgs |
| Temperature | 11,036±375[7] K |
| Rotational velocity (v sin i) | 96[7] km/s |
| Age | 201[7] Myr |
| Other designations | |
| 21 CVn, BK Canum Venaticorum, BD+50°1994, FK5 3063, HD 115735, HIP 64906, HR 5023, SAO 44556[8] | |
| Database references | |
| SIMBAD | data |
21 Canum Venaticorum is a single[9] variable star[5] in the northern constellation of Canes Venatici, located 279 light years away from the Sun.[1] This object has the variable star designation BK Canum Venaticorum; 21 Canum Venaticorum is the Flamsteed designation. It is visible to the naked eye as a faint white-hued star with a baseline apparent visual magnitude of +5.14.[2]
According to Garrison et al. (1994)[3] this is a B-type subgiant star with a stellar classification of B9 IV (Si), where the suffix notation indicates this is a Silicon star. Cowley et al. (1969) listed it with a class of A0 V Si:,[4] which would match an A-type main-sequence star with the ':' indicating some uncertainty in the classification. It is a marginally chemically-peculiar star[10] with weaker than normal helium absorption lines and displaying helium line variability.[11] The widths of the lines of ionized silicon vary with a period of 21.12 ± 0.48 hours.[12]
21 Canum Venaticorum is classified as an Alpha2 Canum Venaticorum type variable star and its brightness varies by 0.04 magnitudes over a period of 18.4 hours.[5] Its variability was discovered in 1984 by Juraj Zverko[13] and it was given its variable star designation in 1987.[14] It is around 201 million years old and is spinning with a relatively high projected rotational velocity of 96 km/s.[7] The star has 2.73[7] times the mass of the Sun and 2.8[6] times the Sun's radius. It is radiating 72[2] times the luminosity of the Sun from its photosphere at an effective temperature of 11,036 K.[7]
References
[edit | edit source]- ^ a b c d e f g Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR3 record for this source at VizieR.
- ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d e f g h Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
