Alpha Cancri
α Cancri, circled, is the bottom left star in the "crab". | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer[1] |
| Right ascension | 08h 58m 29.2042s[2] |
| Declination | +11° 51′ 27.649″[2] |
| Apparent magnitude (V) | 4.20 to 4.27[3] |
| Characteristics | |
| Spectral type | kA7VmF0/2III/IVSr[4] |
| U−B color index | +0.15[5] |
| B−V color index | +0.14[5] |
| R−I color index | +0.04[5] |
| Astrometry | |
| Radial velocity (Rv) | −12.1±0.8[6] km/s |
| Proper motion (μ) | RA: 42.181 mas/yr[2] Dec.: −31.160 mas/yr[2] |
| Parallax (π) | 18.3304±0.3216 mas[2] |
| Distance | 178 ± 3 ly (54.6 ± 1.0 pc) |
| Absolute magnitude (MV) | 0.46[1] |
| Details | |
| A | |
| Mass | 2.10[7] M☉ |
| Radius | 3.655[8] R☉ |
| Luminosity | 49[8] L☉ |
| Surface gravity (log g) | 3.73[9] cgs |
| Temperature | 7,943[9] K |
| Rotational velocity (v sin i) | 75[10] km/s |
| B | |
| Mass | 0.38[7] M☉ |
| Other designations | |
| Acubens, Sertan, Sartan[5], α Cnc, Alpha Cancri, Alpha Cnc, 65 Cancri, 65 Cnc, BD+12 1948, FK5 337, GC 12406, HD 76756, HIP 44066, HR 3572, SAO 98267, PPM 125972, ADS 7115 A, CCDM J08585+1151A[11] | |
| Database references | |
| SIMBAD | data |
| B | |
Alpha Cancri is a star system in the northern constellation of Cancer. Its name is a Bayer designation that is Latinized from α Cancri, and abbreviated Alpha Cnc or α Cnc. The primary component has the proper name Acubens, pronounced /ˈækjuːbɛnz/.[12] It forms a fourth-magnitude star with an apparent magnitude of 4.20, making it barely visible to the naked eye under good viewing conditions. Based on parallax measurements, it is located at a distance of 178 light-years (55 pc) from the Sun, but is drifting closer with a radial velocity of −12 km/s.[6] Since it is near the ecliptic, it can be occulted by the Moon.[13]
Properties
[edit | edit source]The primary component, α Cancri A, has a stellar classification of kA7VmF0/2III/IVSr, indicating an Am star with calcium K-lines similar to an A7 main sequence star and hydrogen lines more like an F0 giant or subgiant star. It is a white A-type main-sequence star with an apparent magnitude of +4.26. The star has 2.10[7] times the mass of the Sun and 3.7[8] times the Sun's radius. It has a high rate of spin, showing a projected rotational velocity of 75 km/s.[10] The star is radiating 49 times the luminosity of the Sun from its photosphere at an effective temperature of 7,943 K.[9]
Its companion, α Cancri B, is an eleventh-magnitude star. In the year 1836, its position angle was observed at 325 degrees with a separation from the main star α Cancri A of 11.3 arcseconds.[14][15] α Cancri A may itself be a close binary, consisting of two stars with similar brightness and a separation of 0.1 arcsecond, though this is questioned.[5] Indeed, a light curve generated during a 2014 lunar occultation failed to demonstrate a close companion.[13]
Nomenclature
[edit | edit source]α Cancri (Latinised to Alpha Cancri) is the star's Bayer designation.
The traditional name Acubens (Açubens) is derived from the Arabic الزبانى al zubanāh, 'the claws'.[16] A second name, Sertan /ˈsɜːrtæn/, derives from the Arabic al-saraṭān, 'the crab'. The International Astronomical Union Working Group on Star Names (WGSN) choose 'Acubens' as the proper name for the primary component of this star.[17]
In modern culture
[edit | edit source]USS Acubens (AKS-5) was a United States Navy ship.
References
[edit | edit source]- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). XHIP record for this object at VizieR.
- ^ a b c d 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.
- ^ 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).
- ^ a b c d e 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). Acubens' database entry at VizieR.
- ^ a b c 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).
- ^ 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).
- ^ a b 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).
External links
[edit | edit source]- Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
