Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Centaurus |
Right ascension | 14h 20m 33.43s[1] |
Declination | −37° 53′ 07.1″[1] |
Apparent magnitude (V) | +4.05[2] |
Characteristics | |
Spectral type | A0 IV[3] (B9 and A2)[4] |
U−B color index | −0.11[3] |
B−V color index | −0.03[3] |
Variable type | eclipsing[4] |
Astrometry | |
Radial velocity (Rv) | 1.8±0.9[5] km/s |
Proper motion (μ) | RA: −63.69±0.18[1] mas/yr Dec.: −10.65±0.15[1] mas/yr |
Parallax (π) | 12.60 ± 0.20 mas[1] |
Distance | 259 ± 4 ly (79 ± 1 pc) |
Absolute magnitude (MV) | −0.35±0.14[6] |
Orbit[4] | |
Period (P) | 38.81252±0.00029 d |
Eccentricity (e) | 0.55408±0.00024 |
Inclination (i) | 88.955±0.012° |
Argument of periastron (ω) (secondary) | 20.095±0.098° |
Semi-amplitude (K1) (primary) | 49.01±0.11[7] km/s |
Semi-amplitude (K2) (secondary) | 79.92±0.15[7] km/s |
Details | |
ψ Cen A | |
Mass | 3.114[8] M☉ |
Radius | 3.634[8] R☉ |
Luminosity | 141[8] L☉ |
Surface gravity (log g) | 3.811±0.003[7] cgs |
Temperature | 10,450[8] K |
Rotation | 1.49±0.26 d[4] |
Rotational velocity (v sin i) | 123.7[7] km/s |
Age | 269[6] Myr |
ψ Cen B | |
Mass | 1.909[8] M☉ |
Radius | 1.811[8] R☉ |
Luminosity | 18[8] L☉ |
Surface gravity (log g) | 4.206±0.007[7] cgs |
Temperature | 8,800[8] K |
Rotational velocity (v sin i) | 126.9[7] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Psi Centauri, which is Latinized from ψ Centauri, is a binary star[10] system in the southern constellation of Centaurus. It is visible to the naked eye with a baseline apparent visual magnitude of +4.05.[2] The distance to this system is approximately 259 light years based on parallax.[1] The radial velocity is poorly constrained, but it appears to be slowly drifting away from the Sun at the rate of +2 km/s.[5]
This is a detached eclipsing binary system with the secondary eclipse being total.[4] The pair are orbiting each other with a period of 38.81 days and an eccentricity of 0.55.[10] The brightness of the system dips by 0.28 and 0.16 magnitude during the two eclipses per orbit.[4] The system displays an infrared excess at a wavelength of 60 μm, indicating the presence of a circumstellar debris disk with a temperature of 120 K, orbiting at a distance of 64 AU.[11]
The pair have a combined stellar classification of A0 IV,[3] matching a white-hued A-type subgiant.[2] The two components appear to be at different evolutionary stages.[4] Both have high rotation rates, with projected rotational velocities over 120 km/s.[7] The primary has 3.6 times the Sun's radius while the secondary is 1.8 times.[8] The primary showed evidence of pulsational behavior with 1.996 and 5.127 cycles per day,[4] which suggests it is a slowly pulsating B star.[7] But this remains unconfirmed as of 2017,[12] and the finding may instead be the result of instrumental error.[7]