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]