Psi Centauri
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 14h 20m 33.43s |
| Declination | −37° 53′ 07.1″ |
| Apparent magnitude (V) | +4.05 |
| Characteristics | |
| Spectral type | A0 IV (B9 and A2) |
| U−B color index | −0.11 |
| B−V color index | −0.03 |
| Variable type | eclipsing |
| Astrometry | |
| Radial velocity (Rv) | 1.8±0.9 km/s |
| Proper motion (μ) | RA: −63.69±0.18 mas/yr Dec.: −10.65±0.15 mas/yr |
| Parallax (π) | 13.049±0.063 mas |
| Distance | 250.0±1.2 ly (76.64±0.37 pc) |
| Absolute magnitude (MV) | −0.35±0.14 |
| Orbit | |
| Period (P) | 38.8121(2) d |
| Semi-major axis (a) | 0.3874±0.0017 |
| Eccentricity (e) | 0.550±0.001 |
| Inclination (i) | 89.20±0.13° |
| Longitude of the node (Ω) | 115.79±0.10° |
| Argument of periastron (ω) (secondary) | 19.45±0.27° |
| Semi-amplitude (K1) (primary) | 49.51±0.16 km/s |
| Semi-amplitude (K2) (secondary) | 80.48±0.33 km/s |
| Details | |
| ψ Cen A | |
| Mass | 3.187±0.031 M☉ |
| Radius | 3.814±0.007 R☉ |
| Luminosity | 140+17 −15 L☉ |
| Surface gravity (log g) | 3.811±0.003 cgs |
| Temperature | 10,450±300 K |
| Metallicity [Fe/H] | +0.05±0.10 dex |
| Rotation | 1.49±0.26 d |
| Rotational velocity (v sin i) | 123.7 km/s |
| Age | 280±10 Myr |
| ψ Cen B | |
| Mass | 1.961±0.015 M☉ |
| Radius | 1.896±0.004 R☉ |
| Luminosity | 17.5+2.6 −2.2 L☉ |
| Surface gravity (log g) | 4.206±0.007 cgs |
| Temperature | 8,800±300 K |
| Metallicity [Fe/H] | +0.05±0.10 dex |
| Rotational velocity (v sin i) | 126.9 km/s |
| Age | 280±10 Myr |
| Other designations | |
| ψ Cen, CD−37°9336, FK5 1373, GC 19337, HD 125473, HIP 70090, HR 5367, SAO 205453, CCDM J14206-3753, WDS J14206-3753 | |
| Database references | |
| SIMBAD | data |
Psi Centauri, which is Latinized from ψ Centauri, is a binary star system in the southern constellation of Centaurus. It is visible to the naked eye with a baseline apparent visual magnitude of +4.05. The distance to this system is 250 light years based on parallax. The radial velocity is poorly constrained, but it appears to be slowly drifting away from the Sun at the rate of +2 km/s.
This is a detached eclipsing binary system with the secondary eclipse being total. The pair are orbiting each other with a period of 38.81 days and an eccentricity of 0.55.The brightness of the system dips by 0.28 and 0.16 magnitude during the two eclipses per orbit. 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.
The pair have a combined stellar classification of A0 IV, matching a white-hued A-type subgiant. The two components appear to be at different evolutionary stages. Both have high rotation rates, with projected rotational velocities over 120 km/s. The primary has 3.814 times the Sun's radius while the secondary is 1.896 times. The primary showed evidence of pulsational behavior with 1.996 and 5.127 cycles per day, which suggests it is a slowly pulsating B star. But this remains unconfirmed as of 2017, and the finding may instead be the result of instrumental error.