# Iota Lupi

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Star in the constellation Lupus

ι Lupi Location of ι Lupi (circled in red) Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) Constellation Lupus Right ascension 14h 19m 24.22219s[1] Declination −46° 03′ 29.1437″[1] Apparent magnitude (V) 3.54[2] Characteristics Spectral type B2.5 IV[3] U−B color index −0.742[2] B−V color index −0.180[2] Astrometry Radial velocity (Rv) 21.6±4.1[4] km/s Proper motion (μ) RA: −12.56[1] mas/yr Dec.: −4.76[1] mas/yr Parallax (π) 9.65±0.20 mas[1] Distance 338 ± 7 ly (104 ± 2 pc) Absolute magnitude (MV) −1.48[5] Details Mass 6.9±0.1[6] M☉ Radius 4.05±0.33[7] R☉ Luminosity (bolometric) 2,082[8] L☉ Surface gravity (log g) 3.94±0.07[7] cgs Temperature 18,605±221[7] K Metallicity [Fe/H] +0.19±0.15[7] dex Rotational velocity (v sin i) 370[9] km/s Age 20.3±4.8[6] Myr Other designations ι Lup, CD−45°9084, HD 125238, HIP 69996, HR 5354, SAO 224833[10] Database references SIMBAD data

**ι Lupi**, Latinised as **Iota Lupi**, is a solitary[11] [star](/source/Star) in the southern [constellation](/source/Constellation) of [Lupus](/source/Lupus_(constellation)). It is visible to the naked eye with an [apparent visual magnitude](/source/Apparent_visual_magnitude) of 3.54.[2] Based upon an annual [parallax shift](/source/Stellar_parallax) of 9.65 [mas](/source/Milliarcsecond) as seen from Earth, it is located around 338 [light years](/source/Light_year) from the [Sun](/source/Sun). At that distance, the visual magnitude of the star is diminished by an [extinction factor](/source/Extinction_(astronomy)) of 0.23 due to [interstellar dust](/source/Interstellar_dust).[5] Relative to its neighbors, this star has a [peculiar velocity](/source/Peculiar_velocity) of 27.4±4.9 km/s.[6] It appears to be a member of the [Scorpio-Centaurus OB association](/source/Scorpius%E2%80%93Centaurus_association).[12]

This star has the [spectrum](/source/Spectrum) of a [B-type](/source/B-type_star) [subgiant star](/source/Subgiant_star) with a [stellar classification](/source/Stellar_classification) of B2.5 IV,[3] which may indicate that it has used up its [core](/source/Stellar_core) supply of [hydrogen](/source/Hydrogen) and has begun to expand off the [main-sequence](/source/Main-sequence). It is rotating rapidly with a [projected rotational velocity](/source/Projected_rotational_velocity) of 370 km/s.[9] This is giving the star an [oblate](/source/Oblate_spheroid) shape with an [equatorial bulge](/source/Equatorial_bulge) that is an estimated 12% larger than the polar radius.[13] It is about 20[6] million years old with 6.9[6] times the [mass of the Sun](/source/Solar_mass) and 4[7] times the Sun's radius. The star radiates 2,082[8] times the [solar luminosity](/source/Solar_luminosity) from its [outer atmosphere](/source/Stellar_atmosphere) at an [effective temperature](/source/Effective_temperature) of 18,605[7] K.

## References

1. ^ [***a***](#cite_ref-vanLeeuwen2007_1-0) [***b***](#cite_ref-vanLeeuwen2007_1-1) [***c***](#cite_ref-vanLeeuwen2007_1-2) [***d***](#cite_ref-vanLeeuwen2007_1-3) [***e***](#cite_ref-vanLeeuwen2007_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).

1. ^ [***a***](#cite_ref-apjs15_2-0) [***b***](#cite_ref-apjs15_2-1) [***c***](#cite_ref-apjs15_2-2) [***d***](#cite_ref-apjs15_2-3) Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", *Astrophysical Journal Supplement*, **15**: 459, [Bibcode](/source/Bibcode_(identifier)):[1968ApJS...15..459G](https://ui.adsabs.harvard.edu/abs/1968ApJS...15..459G), [doi](/source/Doi_(identifier)):[10.1086/190168](https://doi.org/10.1086%2F190168).

1. ^ [***a***](#cite_ref-Hiltner1969_3-0) [***b***](#cite_ref-Hiltner1969_3-1) Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars", *Astrophysical Journal*, **157**: 313–326, [Bibcode](/source/Bibcode_(identifier)):[1969ApJ...157..313H](https://ui.adsabs.harvard.edu/abs/1969ApJ...157..313H), [doi](/source/Doi_(identifier)):[10.1086/150069](https://doi.org/10.1086%2F150069).

1. **[^](#cite_ref-deBruijne2012_4-0)** de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", *Astronomy & Astrophysics*, **546**: 14, [arXiv](/source/ArXiv_(identifier)):[1208.3048](https://arxiv.org/abs/1208.3048), [Bibcode](/source/Bibcode_(identifier)):[2012A&A...546A..61D](https://ui.adsabs.harvard.edu/abs/2012A&A...546A..61D), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201219219](https://doi.org/10.1051%2F0004-6361%2F201219219), [S2CID](/source/S2CID_(identifier)) [59451347](https://api.semanticscholar.org/CorpusID:59451347), A61.

1. ^ [***a***](#cite_ref-Gontcharov2012_5-0) [***b***](#cite_ref-Gontcharov2012_5-1) Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", *Astronomy Letters*, **38** (11): 694–706, [arXiv](/source/ArXiv_(identifier)):[1606.09028](https://arxiv.org/abs/1606.09028), [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..694G](https://ui.adsabs.harvard.edu/abs/2012AstL...38..694G), [doi](/source/Doi_(identifier)):[10.1134/S1063773712110035](https://doi.org/10.1134%2FS1063773712110035), [S2CID](/source/S2CID_(identifier)) [119108982](https://api.semanticscholar.org/CorpusID:119108982).

1. ^ [***a***](#cite_ref-Tetzlaff2011_6-0) [***b***](#cite_ref-Tetzlaff2011_6-1) [***c***](#cite_ref-Tetzlaff2011_6-2) [***d***](#cite_ref-Tetzlaff2011_6-3) [***e***](#cite_ref-Tetzlaff2011_6-4) Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", *Monthly Notices of the Royal Astronomical Society*, **410** (1): 190–200, [arXiv](/source/ArXiv_(identifier)):[1007.4883](https://arxiv.org/abs/1007.4883), [Bibcode](/source/Bibcode_(identifier)):[2011MNRAS.410..190T](https://ui.adsabs.harvard.edu/abs/2011MNRAS.410..190T), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2010.17434.x](https://doi.org/10.1111%2Fj.1365-2966.2010.17434.x), [S2CID](/source/S2CID_(identifier)) [118629873](https://api.semanticscholar.org/CorpusID:118629873).

1. ^ [***a***](#cite_ref-Fitzpatrick2005_7-0) [***b***](#cite_ref-Fitzpatrick2005_7-1) [***c***](#cite_ref-Fitzpatrick2005_7-2) [***d***](#cite_ref-Fitzpatrick2005_7-3) [***e***](#cite_ref-Fitzpatrick2005_7-4) [***f***](#cite_ref-Fitzpatrick2005_7-5) Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", *The Astronomical Journal*, **129** (3): 1642–1662, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0412542](https://arxiv.org/abs/astro-ph/0412542), [Bibcode](/source/Bibcode_(identifier)):[2005AJ....129.1642F](https://ui.adsabs.harvard.edu/abs/2005AJ....129.1642F), [doi](/source/Doi_(identifier)):[10.1086/427855](https://doi.org/10.1086%2F427855), [S2CID](/source/S2CID_(identifier)) [119512018](https://api.semanticscholar.org/CorpusID:119512018).

1. ^ [***a***](#cite_ref-Hohle2010_8-0) [***b***](#cite_ref-Hohle2010_8-1) Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", *Astronomische Nachrichten*, **331** (4): 349, [arXiv](/source/ArXiv_(identifier)):[1003.2335](https://arxiv.org/abs/1003.2335), [Bibcode](/source/Bibcode_(identifier)):[2010AN....331..349H](https://ui.adsabs.harvard.edu/abs/2010AN....331..349H), [doi](/source/Doi_(identifier)):[10.1002/asna.200911355](https://doi.org/10.1002%2Fasna.200911355), [S2CID](/source/S2CID_(identifier)) [111387483](https://api.semanticscholar.org/CorpusID:111387483).

1. ^ [***a***](#cite_ref-UesugiFukuda70_9-0) [***b***](#cite_ref-UesugiFukuda70_9-1) Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", *Contributions from the Institute of Astrophysics and Kwasan Observatory*, [University of Kyoto](/source/University_of_Kyoto), [Bibcode](/source/Bibcode_(identifier)):[1970crvs.book.....U](https://ui.adsabs.harvard.edu/abs/1970crvs.book.....U).

1. **[^](#cite_ref-SIMBAD_10-0)** ["iot Lup -- Variable Star"](https://simbad.u-strasbg.fr/simbad/sim-id?Ident=iot+Lup), *SIMBAD Astronomical Database*, [Centre de Données astronomiques de Strasbourg](/source/Centre_de_Donn%C3%A9es_astronomiques_de_Strasbourg), retrieved 2017-03-05.

1. **[^](#cite_ref-Eggleton2008_11-0)** Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", *[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society)*, **389** (2): 869–879, [arXiv](/source/ArXiv_(identifier)):[0806.2878](https://arxiv.org/abs/0806.2878), [Bibcode](/source/Bibcode_(identifier)):[2008MNRAS.389..869E](https://ui.adsabs.harvard.edu/abs/2008MNRAS.389..869E), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2008.13596.x](https://doi.org/10.1111%2Fj.1365-2966.2008.13596.x), [S2CID](/source/S2CID_(identifier)) [14878976](https://api.semanticscholar.org/CorpusID:14878976).

1. **[^](#cite_ref-deGeus1989_12-0)** de Geus, E. J.; et al. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", *Astronomy and Astrophysics*, **216** (1–2): 44–61, [Bibcode](/source/Bibcode_(identifier)):[1989A&A...216...44D](https://ui.adsabs.harvard.edu/abs/1989A&A...216...44D).

1. **[^](#cite_ref-belle2012_13-0)** Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", *The Astronomy and Astrophysics Review*, **20** (1): 51, [arXiv](/source/ArXiv_(identifier)):[1204.2572](https://arxiv.org/abs/1204.2572), [Bibcode](/source/Bibcode_(identifier)):[2012A&ARv..20...51V](https://ui.adsabs.harvard.edu/abs/2012A&ARv..20...51V), [doi](/source/Doi_(identifier)):[10.1007/s00159-012-0051-2](https://doi.org/10.1007%2Fs00159-012-0051-2), [S2CID](/source/S2CID_(identifier)) [119273474](https://api.semanticscholar.org/CorpusID:119273474).

## External links

- Kaler, James B. (August 9, 2013), ["Iota Lupi"](http://stars.astro.illinois.edu/sow/iotalup.html), *Stars*, University of Illinois, retrieved 2017-03-06.

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 [Iota Lupi](https://en.wikipedia.org/wiki/Iota_Lupi) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Iota_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.