Pi Boötis
Pi Boötis, Latinized from π Boötis, is a probable triple star[10] system in the northern constellation of Boötes. It is visible to the naked eye with a combined apparent visual magnitude of 4.50.[1] Based upon an annual parallax shift of 10.67[1] mas as seen from Earth, it is located roughly 310 light years from the Sun.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 40m 43.56087s[1] |
| Declination | +16° 25′ 05.8863″[1] |
| Apparent magnitude (V) | 4.5038[1] (4.893 + 5.761)[2] |
| Characteristics | |
| Spectral type | B9 IIIp (MnHgSi) + A6 V[3] |
| U−B color index | −0.31[4] |
| B−V color index | −0.03[4] |
| R−I color index | −0.02 |
| Astrometry | |
| Radial velocity (Rv) | −1.1±0.8[5] km/s |
| Proper motion (μ) | RA: +11.44[1] mas/yr Dec.: +9.47[1] mas/yr |
| Parallax (π) | 10.67 ± 1.35 mas[1] |
| Distance | approx. 310 ly (approx. 90 pc) |
| Absolute magnitude (MV) | –0.39[6] |
| Details[6] | |
| π1 Boo | |
| Mass | 3.49±0.14 M☉ |
| Radius | 3.2±0.4 R☉ |
| Luminosity | 214 L☉ |
| Surface gravity (log g) | 3.99±0.18[7] cgs |
| Temperature | 12,052±456[7] K |
| Metallicity [Fe/H] | +0.18±0.17[7] dex |
| Rotational velocity (v sin i) | 14.0[8] km/s |
| Other designations | |
| π1 Boötis: HD 129174, HR 5475, SAO 101138 | |
| π2 Boötis: HD 129175, HR 5476, SAO 101139 | |
| Database references | |
| SIMBAD | data |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) | |
The brighter primary, component π1 Boötis, has a visual magnitude of 4.89[2] and a stellar classification of B9 IIIp (MnHgSi),[3] which suggests it is an evolved blue-white hued B-type giant star. It is a chemically peculiar star of the HgMn type,[8] with a spectrum that displays anomalous overabundances of mercury, manganese, and silicon.[3] This component is most likely a single-lined spectroscopic binary with an unknown companion.[10] Its magnitude 5.76[2] visible companion, π2 Boötis, is a white-hued A-type main-sequence star with a class of A6 V.[3] As of 2010, the pair were separated by 5.537±0.003 arcseconds on the sky along a position angle of 110.5°±0.5°. This corresponds to a projected separation of 538.6±47.7 AU. The odds that is a mere chance alignment is 0.85%.[10]
Pi Boötis has the Chinese traditional star name 左攝提二 (Zuǒ shè tí èr)
References
- ^ a b c d e f g h van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c Høg, E.; et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862.
- ^ a b c d Abt, H. A.; Cardona, O. (January 1, 1984), "The nature of the visual companions of Ap and Am stars", Astrophysical Journal, Part 1, 276: 266–269, Bibcode:1984ApJ...276..266A, doi:10.1086/161610.
- ^ a b Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
- ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b North, P. (June 1998), "Do SI stars undergo any rotational braking?", Astronomy and Astrophysics, 334: 181–187, arXiv:astro-ph/9802286, Bibcode:1998A&A...334..181N.
- ^ a b c Prugniel, P.; et al. (2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv:1104.4952, Bibcode:2011A&A...531A.165P, doi:10.1051/0004-6361/201116769, S2CID 54940439.
- ^ a b Ghazaryan, S.; Alecian, G. (August 2016), "Statistical analysis from recent abundance determinations in HgMn stars", Monthly Notices of the Royal Astronomical Society, 460 (2): 1912–1922, Bibcode:2016MNRAS.460.1912G, doi:10.1093/mnras/stw911
- ^ "pi Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-10-18.
- ^ a b c Schöller, M.; et al. (November 2010), "Multiplicity of late-type B stars with HgMn peculiarity", Astronomy and Astrophysics, 522: 12, arXiv:1010.3643, Bibcode:2010A&A...522A..85S, doi:10.1051/0004-6361/201014246, S2CID 119273467, A85
External links
- Kaler, James B. (April 22, 2011), "Pi Bootis", Stars, University of Illinois, retrieved 2017-10-13.
- HR 5475
- CCDM J14407+1625
- Image Pi Boötis