Pi Boötis

Pi Boötis
Observation data; Epoch J2000 Equinox J2000
Constellation	Boötes
Right ascension	14h 40m 43.56087s
Declination	+16° 25′ 05.8863″
Apparent magnitude (V)	4.5038 (4.893 + 5.761)
Characteristics
Spectral type	B9 IIIp (MnHgSi) + A6 V
U−B color index	−0.31
B−V color index	−0.03
R−I color index	−0.02
Astrometry
Radial velocity (Rv)	−1.1±0.8 km/s
Proper motion (μ)	RA: +11.44 mas/yr ; Dec.: +9.47 mas/yr
Parallax (π)	10.67 ± 1.35 mas
Distance	approx. 310 ly ; (approx. 90 pc)
Absolute magnitude (MV)	–0.39
Details
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 cgs
Temperature	12,052±456 K
Metallicity [Fe/H]	+0.18±0.17 dex
Rotational velocity (v sin i)	14.0 km/s
Other designations
	π Boo, 29 Boötis, BD+17° 2768, HIP 71762, ADS 9338
	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.)

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.

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

[vanLeeuwen2007-1] ^ ^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.

[Hog2000-2] 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.

[Abt1984-3] 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.

[Nicolet1978-4] 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.

[Gontcharov2006-5] 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.

[North1998-6] 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.

[prugniel2011-7] 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.

[Ghazaryan2016-8] 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

[SIMBAD-9] "pi Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-10-18.

[Shoeller2010-10] 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

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Observation data Epoch J2000 Equinox J2000
Constellation	Boötes
Right ascension	14^h 40^m 43.56087^s^[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 (R_v)	−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 (M_V)	–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
π Boo, 29 Boötis, BD+17° 2768, HIP 71762, ADS 9338^[9]
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.)