  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02h 49m 17.55924s[1] |
| Declination | +17° 27′ 51.5168″[1] |
| Apparent magnitude (V) | 5.21[2] |
| Characteristics | |
| Spectral type | B6 V + A0 V + F8 V[3] |
| U−Bcolor index | –0.47[2] |
| B−Vcolor index | –0.06[2] |
| Astrometry | |
| Radial velocity (Rv) | +8.8[4] km/s |
| Proper motion (μ) | RA: +2.60[1]mas/yr Dec.: –14.10[1]mas/yr |
| Parallax (π) | 4.18±0.69 mas[1] |
| Distance | approx. 800 ly (approx. 240 pc) |
| Absolute magnitude (MV) | −1.56[5] |
| Details | |
| Luminosity | 538[5] L☉ |
| Rotational velocity (v sin i) | 70[6] km/s |
| Other designations | |
| π Ari, 42 Arietis,BD+16° 355,HD 17543,HIP 13165,HR 836,SAO 93127.[7] | |
| Database references | |
| SIMBAD | data |
Pi Arietis,Latinized from π Arietis, is theBayer designation for a multiplestar system in the northernconstellation ofAries. Based uponparallax measurements made during theHipparcos mission, this system is approximately 800light-years (250parsecs) distant fromEarth and has anapparent visual magnitude of 5.21. This is bright enough to be faintly seen with the naked eye.
The primary member of this system is a massive,B-type main sequence star with astellar classification of B6 V. It is a closespectroscopic binary with anorbital period of 3.854 days, aneccentricity of 0.04, and a combined visual magnitude of 5.30. At anangular separation of 3.28 arcseconds is a magnitude 8.46A-type main sequence star with a classification of A0 Vp. Finally, a fourth member of the system is a magnitude 11.0F-type main sequence star with a classification of F8V at an angular separation of 25.2 arcseconds from the primary.[3]
This star, along withδ Ari,ε Ari,ζ Ari, andρ3 Ari, were Al Bīrūnī'sAl Buṭain (ألبطين), the dual ofAl Baṭn, the Belly.[8] According to the catalogue of stars in theTechnical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars,Al Buṭain were the title for five stars :δ Ari asBotein, π Ari asAl Buṭain I,ρ3 Ari asAl Buṭain II,ε Ari asAl Buṭain III danζ Ari asAl Buṭain IV.[9]
InChinese,左更 (Zuǒ Gēng), meaningOfficial in Charge of the Forest, refers to an asterism consisting of π Arietis,ν Arietis,μ Arietis,ο Arietis andσ Arietis.[10] Consequently, theChinese name for π Arietis itself is左更五 (Zuǒ Gēng wu, English:the Fifth Star of Official in Charge of the Forest.)[11]
