# Pi Lupi

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Multiple star system in the constellation Lupus

π Lupi Location of π Lupi (circled in red) Observation data Epoch J2000 Equinox J2000 Constellation Lupus Right ascension 15h 05m 07.08596s[1] Declination −47° 03′ 04.4976″[1] Apparent magnitude (V) 3.89[2] Characteristics Spectral type B5V + B5IV[3] U−B color index −0.59[2] B−V color index −0.14[2] Astrometry Radial velocity (Rv) +4.50[4] km/s Proper motion (μ) RA: −22.98[1] mas/yr Dec.: −22.81[1] mas/yr Parallax (π) 7.36±0.55 mas[1] Distance 440 ± 30 ly (140 ± 10 pc) Details A Mass 4.5[5] M☉ Surface gravity (log g) 4.5[5] cgs Temperature 16,000[5] K Rotational velocity (v sin i) 10[5] km/s B Mass 4.7[5] M☉ Temperature 14,000[5] K Rotational velocity (v sin i) 10[5] km/s Age 14[5] Myr Other designations CD−46°9773, HIP 73807, SAO 225426 π Lupi A: HD 133242, HR 5605 π Lupi B: HD 133243, HR 5606 Database references SIMBAD data A B

**π Lupi** (Latinised to Pi Lupi) is a multiple star system in the southern constellation [Lupus](/source/Lupus_(constellation)). Two components form a wide binary pair with an orbital period of 517 years and a [semimajor axis](/source/Semimajor_axis) of 1.59″. They belong to the Upper Centaurus Lupus component of the [Sco–Cen complex](/source/Scorpius%E2%80%93Centaurus_association).[3]

A [light curve](/source/Light_curve) for Pi Lupi, adapted from Sharma *et al.* (2022)[6]

At least one of the components is a [spectroscopic binary](/source/Spectroscopic_binary) and produces eclipses 15.5 days apart, making it an [eclipsing binary](/source/Eclipsing_binary). There are also other brightness variations with a period of 16 hours that are likely to be pulsations of the [Slowly pulsating B-type star](/source/Slowly_pulsating_B-type_star). The eclipses are shallow, with the brightness dropping by only 1% or about 0.01 magnitudes. The amplitude of the pulsations is even smaller.[6]

π Lupi A (HR 5605, HD 133242) has been classified as a spectroscopic binary by at least two studies,[7][8] but both components may be spectroscopic binaries.[9]

## References

1. ^ [***a***](#cite_ref-van_Leeuwen2007_1-0) [***b***](#cite_ref-van_Leeuwen2007_1-1) [***c***](#cite_ref-van_Leeuwen2007_1-2) [***d***](#cite_ref-van_Leeuwen2007_1-3) [***e***](#cite_ref-van_Leeuwen2007_1-4) van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", *Astronomy and Astrophysics*, **474** (2): 653–664, [arXiv](/source/ArXiv_(identifier)):[0708.1752](https://arxiv.org/abs/0708.1752), [Bibcode](/source/Bibcode_(identifier)):[2007A&A...474..653V](https://ui.adsabs.harvard.edu/abs/2007A&A...474..653V), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20078357](https://doi.org/10.1051%2F0004-6361%3A20078357), [S2CID](/source/S2CID_(identifier)) [18759600](https://api.semanticscholar.org/CorpusID:18759600)[Vizier catalog entry](http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=114184) [Archived](https://web.archive.org/web/20200901074941/http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I%2F311%2Fhip2&recno=114184) 2020-09-01 at the [Wayback Machine](/source/Wayback_Machine)

1. ^ [***a***](#cite_ref-aass34_1_2-0) [***b***](#cite_ref-aass34_1_2-1) [***c***](#cite_ref-aass34_1_2-2) Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", *Astronomy and Astrophysics Supplement Series*, **34**: 1–49, [Bibcode](/source/Bibcode_(identifier)):[1978A&AS...34....1N](https://ui.adsabs.harvard.edu/abs/1978A&AS...34....1N)

1. ^ [***a***](#cite_ref-Nitschelm2004_3-0) [***b***](#cite_ref-Nitschelm2004_3-1) Nitschelm, C. (December 2004), Hilditch, R. W.; Hensberge, H.; Pavlovski, K. (eds.), "Discovery and confirmation of some double-lined spectroscopic binaries in the Sco-Cen Complex", *Spectroscopically and Spatially Resolving the Components of the Close Binary Stars, Proceedings of the Workshop held 20–24 October 2003 in Dubrovnik, Croatia.*, ASP Conference Series, vol. 318, [Astronomical Society of the Pacific](/source/Astronomical_Society_of_the_Pacific), pp. 291–293, [Bibcode](/source/Bibcode_(identifier)):[2004ASPC..318..291N](https://ui.adsabs.harvard.edu/abs/2004ASPC..318..291N)

1. **[^](#cite_ref-an328_9_889_4-0)** Kharchenko, N. V.; et al. (2007), "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations", *Astronomische Nachrichten*, **328** (9): 889–896, [arXiv](/source/ArXiv_(identifier)):[0705.0878](https://arxiv.org/abs/0705.0878), [Bibcode](/source/Bibcode_(identifier)):[2007AN....328..889K](https://ui.adsabs.harvard.edu/abs/2007AN....328..889K), [doi](/source/Doi_(identifier)):[10.1002/asna.200710776](https://doi.org/10.1002%2Fasna.200710776), [S2CID](/source/S2CID_(identifier)) [119323941](https://api.semanticscholar.org/CorpusID:119323941)

1. ^ [***a***](#cite_ref-Gullikson2016_5-0) [***b***](#cite_ref-Gullikson2016_5-1) [***c***](#cite_ref-Gullikson2016_5-2) [***d***](#cite_ref-Gullikson2016_5-3) [***e***](#cite_ref-Gullikson2016_5-4) [***f***](#cite_ref-Gullikson2016_5-5) [***g***](#cite_ref-Gullikson2016_5-6) [***h***](#cite_ref-Gullikson2016_5-7) Gullikson, Kevin; Kraus, Adam; Dodson-Robinson, Sarah (25 July 2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", *The Astronomical Journal*, **152** (2): 40, [arXiv](/source/ArXiv_(identifier)):[1604.06456](https://arxiv.org/abs/1604.06456), [Bibcode](/source/Bibcode_(identifier)):[2016AJ....152...40G](https://ui.adsabs.harvard.edu/abs/2016AJ....152...40G), [doi](/source/Doi_(identifier)):[10.3847/0004-6256/152/2/40](https://doi.org/10.3847%2F0004-6256%2F152%2F2%2F40), [eISSN](/source/EISSN_(identifier)) [1538-3881](https://search.worldcat.org/issn/1538-3881)

1. ^ [***a***](#cite_ref-Sharma_6-0) [***b***](#cite_ref-Sharma_6-1) Sharma, Awshesh N.; Bedding, Timothy R.; Saio, Hideyuki; White, Timothy R. (2022), "Pulsating B stars in the Scorpius–Centaurus Association with TESS", *Monthly Notices of the Royal Astronomical Society*, **515** (1): 828–840, [arXiv](/source/ArXiv_(identifier)):[2203.02582](https://arxiv.org/abs/2203.02582), [Bibcode](/source/Bibcode_(identifier)):[2022MNRAS.515..828S](https://ui.adsabs.harvard.edu/abs/2022MNRAS.515..828S), [doi](/source/Doi_(identifier)):[10.1093/mnras/stac1816](https://doi.org/10.1093%2Fmnras%2Fstac1816)

1. **[^](#cite_ref-buscombe1975_7-0)** Buscombe, W.; Stoeckley, T. R. (1975), "Absorption Line Profiles and Rotational Velocities for 59 Stars", *Astrophysics and Space Science*, **37** (1): 197, [Bibcode](/source/Bibcode_(identifier)):[1975Ap&SS..37..197B](https://ui.adsabs.harvard.edu/abs/1975Ap&SS..37..197B), [doi](/source/Doi_(identifier)):[10.1007/BF00646073](https://doi.org/10.1007%2FBF00646073), [S2CID](/source/S2CID_(identifier)) [122985118](https://api.semanticscholar.org/CorpusID:122985118)

1. **[^](#cite_ref-chini2012_8-0)** Chini, R.; Hoffmeister, V. H.; Nasseri, A.; Stahl, O.; Zinnecker, H. (2012), "A spectroscopic survey on the multiplicity of high-mass stars", *Monthly Notices of the Royal Astronomical Society*, **424** (3): 1925, [arXiv](/source/ArXiv_(identifier)):[1205.5238](https://arxiv.org/abs/1205.5238), [Bibcode](/source/Bibcode_(identifier)):[2012MNRAS.424.1925C](https://ui.adsabs.harvard.edu/abs/2012MNRAS.424.1925C), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2012.21317.x](https://doi.org/10.1111%2Fj.1365-2966.2012.21317.x), [S2CID](/source/S2CID_(identifier)) [119120749](https://api.semanticscholar.org/CorpusID:119120749)

1. **[^](#cite_ref-wds_9-0)** Mason, Brian D.; et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", *The Astronomical Journal*, **122** (6): 3466–3471, [Bibcode](/source/Bibcode_(identifier)):[2001AJ....122.3466M](https://ui.adsabs.harvard.edu/abs/2001AJ....122.3466M), [doi](/source/Doi_(identifier)):[10.1086/323920](https://doi.org/10.1086%2F323920)

v t e Constellation of Lupus List of stars in Lupus Lupus in Chinese astronomy Stars Bayer α (Uridim) β γ δ ε ζ η θ ι κ λ μ ν1 ν2 ξ ο π ρ σ τ1 τ2 υ φ1 φ2 χ ψ1 ψ2 ω Flamsteed 1 (i) 2 (f) Variable RU EX GG GQ HR II IL IM KT (d) V407 V462 HR 5362 5364 5401 5651 (e) 5724 (k) 5825 (g) 5943 5967 HD 134004 135344 136164 141943 142527 143811 Other Gliese 588 HIP 70849 Lupus-TR-3 SSSPM J1549−3544 WASP-132 Exoplanets GQ Lupi b HIP 70849 b Lupus-TR-3b WASP-178b Star clusters NGC 5749 NGC 5822 NGC 5824 NGC 5927 NGC 5986 Nebulae IC 4406 NGC 5882 Galaxies IC 4444 NGC 5530 NGC 5643 Astronomical events SN 1006 Category

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Adapted from the Wikipedia article [Pi Lupi](https://en.wikipedia.org/wiki/Pi_Lupi) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Pi_Lupi?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.