Beta Chamaeleontis
Star in the constellation Chamaeleon
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Beta Chamaeleontis is the third-brightest star in the southern constellation of Chamaeleon. Its name is a Bayer designation that is Latinized from β Chamaeleontis, and abbreviated Beta Cha or β Cha. A solitary,[14] suspected variable star,[4] it is visible to the naked eye as a faint blue-white point of light with an apparent visual magnitude that has been measured ranging between 4.24 and 4.30.[4] Parallax measurements yield a distance estimate of 298 light-years (91 pc) from the Sun. It is drifting further away with a radial velocity of +23 km/s.[9]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Chamaeleon[1] |
| Right ascension | 12h 18m 20.82459s[2] |
| Declination | −79° 18′ 44.0710″[2] |
| Apparent magnitude (V) | 4.24[3] (4.24 to 4.30)[4] |
| Characteristics | |
| Evolutionary stage | main sequence[5] |
| Spectral type | B4 V[6] or B5 IV[7] |
| U−B color index | −0.52[3] |
| B−V color index | −0.13[3] |
| R−I color index | −0.10[8] |
| Variable type | SPB[7] |
| Astrometry | |
| Radial velocity (Rv) | +23.0[9] km/s |
| Proper motion (μ) | RA: −37.97 mas/yr[2] Dec.: +11.15 mas/yr[2] |
| Parallax (π) | 10.93±0.15 mas[2] |
| Distance | 298 ± 4 ly (91 ± 1 pc) |
| Absolute magnitude (MV) | −0.57[1] |
| Details | |
| Mass | 5.0±0.1[10] M☉ |
| Radius | 2.84±0.13[11] R☉ |
| Luminosity | 212[12] L☉ |
| Surface gravity (log g) | 4.03±0.05[11] cgs |
| Temperature | 14,495±157[11] K |
| Rotational velocity (v sin i) | 255[8] km/s |
| Age | 22.7±7.2[10] Myr |
| Other designations | |
| β Cha, CD−78°495, CPD−78°741, FK5 459, GC 16775, HD 106911, HIP 60000, HR 4674, SAO 256924, PPM 371459[13] | |
| Database references | |
| SIMBAD | data |
This is a B-type main-sequence star with a stellar classification of B4 V[6] that is generating energy through core hydrogen fusion. It has been catalogued both as a Be star[3] and a normal star.[15] Based on pulsation measurements made by the TESS space telescope, this is a slowly pulsating B-type variable.[7]
Beta Chamaeleontis is about 23[10] million years old with a high projected rotational velocity of 255 km/s.[8] The rapid rotation is creating an equatorial bulge that is 12% larger than the polar radius.[16] The star has five[10] times the mass of the Sun and 2.8[11] times the Sun's radius. It is radiating 212[12] times the luminosity of the Sun from its photosphere at an effective temperature of 14,495 K.[11]