Alpha Chamaeleontis
Star in the constellation Chamaleon
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Alpha Chamaeleontis, Latinized from α Chamaeleontis, is a solitary[11] star in the southern circumpolar constellation of Chamaeleon. It has an apparent visual magnitude of 4.06[2] and thus is bright enough to be seen with the naked eye. With an annual parallax shift of 51.12 mas,[1] it is located 63.8 light years from the Sun. The star is drifting closer with a radial velocity of −13 km/s,[5] and is predicted to come to within 47 light-years in 666,000 years.[6]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 08h 18m 31.55319s[1] |
| Declination | −76° 55′ 10.9964″[1] |
| Apparent magnitude (V) | 4.06[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | F5 V Fe-0.8[4] |
| U−B color index | −0.04[2] |
| B−V color index | +0.40[2] |
| Astrometry | |
| Radial velocity (Rv) | −13.4±0.5[5] km/s |
| Proper motion (μ) | RA: 111.12[1] mas/yr Dec.: 107.49[1] mas/yr |
| Parallax (π) | 51.12±0.12 mas[1] |
| Distance | 63.8 ± 0.1 ly (19.56 ± 0.05 pc) |
| Absolute magnitude (MV) | +2.59[6] |
| Details | |
| Mass | 1.42[7] M☉ |
| Radius | 2.11+0.14 −0.05[8] R☉ |
| Luminosity | 7.542±0.062[8] L☉ |
| Surface gravity (log g) | 4.28±0.14[7] cgs |
| Temperature | 6,580+91 −209[8] K |
| Metallicity [Fe/H] | −0.26[4] dex |
| Rotational velocity (v sin i) | 0[9] km/s |
| Age | 1.8[7] Gyr |
| Other designations | |
| α Cha, Alpha Cha, CPD−76°507, GJ 305, HD 71243, HIP 40702, HR 3318, SAO 256496[10] | |
| Database references | |
| SIMBAD | data |
This is an F-type main sequence star with a stellar classification of F5 V Fe−0.8,[4] where the 'Fe−0.8' notation indicates an anomalously low abundance of iron. It has an estimated 1.4 times the mass of the Sun,[7] 2.1 times the Sun's radius,[8] and radiates 7.5 times the solar luminosity from its outer atmosphere at an effective temperature of 6,580 K.[8] The star is around 1.8[7] billion years old with a projected rotational velocity that is too low to be measured.[9] The star has been examined for an infrared excess that would suggest the presence of an orbiting debris disk, but none was found.[12]