Delta2 Chamaeleontis
Star in the constellation Chamaeleon
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Delta2 Chamaeleontis is a solitary[11] star located in the southern circumpolar constellation of Chamaeleon. Its name is a Bayer designation that is Latinized from δ2 Chamaeleontis, and abbreviated Delta2 Cha or δ2 Cha. This star has an apparent visual magnitude of 4.42,[3] which is bright enough it to be viewed with the naked eye. Based upon an annual parallax shift of 8.73 mas,[2] it is located at a distance of around 374 light-years (115 pc) 351 light years from the Sun. The star is drifting further away with a line of sight velocity component of +23 km/s.[7]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Chamaeleon[1] |
| Right ascension | 10h 45m 47.00487s[2] |
| Declination | −80° 32′ 24.6785″[2] |
| Apparent magnitude (V) | 4.42[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | B3 V[4] or B2.5 IV[5] |
| U−B color index | −0.728[3] |
| B−V color index | −0.192[3] |
| Variable type | β Cep+SPB[6] |
| Astrometry | |
| Radial velocity (Rv) | +22.6[7] km/s |
| Proper motion (μ) | RA: −36.917 mas/yr[2] Dec.: +6.327 mas/yr[2] |
| Parallax (π) | 8.7273±0.1058 mas[2] |
| Distance | 374 ± 5 ly (115 ± 1 pc) |
| Absolute magnitude (MV) | −0.71[1] |
| Details | |
| Mass | 5.0±0.1[8] M☉ |
| Radius | 3.9[9] R☉ |
| Luminosity | 1,072[6] L☉ |
| Temperature | 18,363[6] K |
| Rotational velocity (v sin i) | 55[6] km/s |
| Age | 32.6±16.3[8] Myr |
| Other designations | |
| δ2 Cha, CPD−79°556, FK5 411, HD 93845, HIP 52633, HR 4234, SAO 258593[10] | |
| Database references | |
| SIMBAD | data |
This star is one of two systems named Delta Chamaeleontis, the other being the fainter Delta1 Chamaeleontis located about 6 arcminutes away.[12] Delta Chamaeleontis forms the southernmost component of the constellation's "dipper" or bowl. Together with Gamma Chamaeleontis, they point to a spot that is within 2° of the south celestial pole.[13]
Delta2 Chamaeleontis is a B-type main sequence star with a stellar classification of B3 V.[4] However, Hiltner et al. (1969) give a classification of B2.5 IV,[5] which would suggest it is a more evolved subgiant star. Based on data from the TESS space telescope, it is a pulsating star that displays characteristics of a Beta Cephei variable, a slowly pulsating B-type star, and a rotating variable.[6]
It is estimated to have five[8] times the mass of the Sun and 3.9[9] times the Sun's radius. With an age of 32.6[8] million years, it has a high rate of spin, showing a projected rotational velocity of 55 km/s. It is radiating over 1,000 times the solar luminosity from its outer atmosphere at an effective temperature of 18,363 K.[6] There is a 70% likelihood that this star is a member of Gould's Belt.[14]