Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Chamaeleon |
Right ascension | 11h37m 15.63631s[1] |
Declination | −75° 53′ 47.5626″[1] |
Apparent magnitude (V) | 5.64[2] |
Characteristics | |
Spectral type | A9 IV[3] or F1 III[4] |
U−B color index | −0.01[5] |
B−V color index | +0.35[5] |
Astrometry | |
Radial velocity (Rv) | −9.8±3.7[6] km/s |
Proper motion (μ) | RA: −127.94[1] mas/yr Dec.: −1.82[1] mas/yr |
Parallax (π) | 24.09 ± 0.33 mas[1] |
Distance | 135 ± 2 ly (41.5 ± 0.6 pc) |
Absolute magnitude (MV) | 2.56[7] |
Orbit[1] | |
Period (P) | 223.1845±1.9460 d |
Semi-major axis (a) | 7.86±0.83 mas |
Eccentricity (e) | 0.3244±0.1375 |
Inclination (i) | 104.88±5.52° |
Details | |
Mass | 1.52[8] M☉ |
Radius | 2.2[9] R☉ |
Luminosity | 8[9] L☉ |
Surface gravity (log g) | 4.08[8] cgs |
Temperature | 6,853±80[6] K |
Metallicity [Fe/H] | −0.28[6] dex |
Rotational velocity (v sin i) | 50[10] km/s |
Age | 1.8±0.1[7] Gyr |
Other designations | |
π Cha, CPD−75°744, FK5 438, HD 101132, HIP 56675, HR 4479, SAO 256857[11] | |
Database references | |
SIMBAD | data |
Pi Chamaeleontis, its name Latinized from π Chamaeleontis, is a binary star[12][13] system located in the southern circumpolar constellationofChamaeleon. It is dimly visible to the naked eye with an apparent visual magnitude of 5.64.[2] Parallax measurements by Hipparcos put the system approximately 135 light-years (41.5 parsecs) away.[1] It is drifting closer with a radial velocity of −10 km/s.[6]
The Hipparcos satellite mission derived a 223 d orbit on the basis of its motion caused by an unseen companion.[1] The visible component is an A-type subgiant[3]orF-type giant star with an effective temperature of about 6,900 K.[6] It has an absolute magnitude of 2.56,[7] a mass of 1.52 M☉,[8] and a radius of 2.2 M☉.[9] It is roughly 1.8 billion years old.[7]