# Iota2 Librae

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A-type main-sequence star

For other stars with this Bayer designation, see [ι Librae](/source/Iota_Librae).

Iota2 Librae Location of ι2 Librae (circled in red) Observation data Epoch J2000 Equinox J2000 Constellation Libra[1] Right ascension 15h 13m 19.1935s[2] Declination −19° 38′ 51.274″[2] Apparent magnitude (V) 6.066[3] Characteristics Evolutionary stage main sequence[2] Spectral type A2V[4] Astrometry Radial velocity (Rv) −7.61±0.56[2] km/s Proper motion (μ) RA: −50.808 mas/yr[2] Dec.: −33.581 mas/yr[2] Parallax (π) 11.2409±0.2282 mas[2] Distance 290 ± 6 ly (89 ± 2 pc) Absolute magnitude (MV) +1.86[1] Details Mass 1.84[5] M☉ Radius 2.314[6] R☉ Luminosity 20.33[6] L☉ Surface gravity (log g) 3.95[5] cgs Temperature 8,526±290[5] K Age 363[5] Myr Other designations Iota2 Librae, 25 Librae, BD−19 4055, HD 134967, HIP 74493, HR 5656, PPM 229920, TIC 70367797, TYC 6178-684-1, 2MASS J15131920-1938512[7] Database references SIMBAD data

**Iota2 Librae** is a faint, sixth-[magnitude](/source/Magnitude_(astronomy)) star situated in the [zodiacal](/source/Zodiac) constellation [Libra](/source/Libra_(constellation)). It has a [stellar spectrum](/source/Spectral_type) of A2V. This indicate that it is in the [main sequence](/source/Main_sequence). [Parallax](/source/Parallax) measurements imply a distance of 89 parsecs (290 ly) from Earth. At this distance, [interstellar extinction](/source/Interstellar_extinction) caused by interveining [gas and dust](/source/Cosmic_dust) makes Iota2 Librae 0.44 magnitudes fainter as seen from Earth. The star is currently drifting closer at 7.61 km/s.[2]

This [A-type star](/source/A-type_star) has 84% more mass and 2.3 times the radius of the Sun. It is about 360 million years old, is 20 times more energetic and 48% hotter than the Sun, its surface has an [effective temperature](/source/Effective_temperature) of 8,526 [K](/source/Kelvin).[6][5] It is also known by its [Flamsteed designation](/source/Flamsteed_designation) 25 Librae, Iota2 Librae is the [Bayer designation](/source/Bayer_designation), with the corresponding [Greek letter](/source/Greek_letter) being shared with another star, [Iota1 Librae](/source/Iota1_Librae). Other designations, like [HD](/source/Henry_Draper_catalogue) 134967 or [HR](/source/Bright_Star_Catalogue) 5656, are [catalogue](/source/Astronomical_catalog) entries.

## References

1. ^ [***a***](#cite_ref-xhip_1-0) [***b***](#cite_ref-xhip_1-1) Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". *[Astronomy Letters](/source/Astronomy_Letters)*. **38** (5): 331. [arXiv](/source/ArXiv_(identifier)):[1108.4971](https://arxiv.org/abs/1108.4971). [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..331A](https://ui.adsabs.harvard.edu/abs/2012AstL...38..331A). [doi](/source/Doi_(identifier)):[10.1134/S1063773712050015](https://doi.org/10.1134%2FS1063773712050015). [XHIP record for this object](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-ref=VIZ681510a8389ecb&-out.src=V%2F137D%2FXHIP&-nav=cat%3AV%2F137D%26tab%3A{V%2F137D%2FXHIP}%26key%3Asource%3DV%2F137D%2FXHIP%26HTTPPRM%3A&-source=V%2F137D%2FXHIP&-out=HIP&HIP=74493&-out=Comp&-out=Gr&-out=RAJ2000&-out=DEJ2000&-out=Dist&-out=X&-out=Y&-out=Z&-out=SpType&-out=Simbad&-out=Hpmag&-out=Lum&-out=Cst) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-dr3_2-0) [***b***](#cite_ref-dr3_2-1) [***c***](#cite_ref-dr3_2-2) [***d***](#cite_ref-dr3_2-3) [***e***](#cite_ref-dr3_2-4) [***f***](#cite_ref-dr3_2-5) [***g***](#cite_ref-dr3_2-6) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D6256370631203976832%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-tycho2_3-0)** Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". *Astronomy and Astrophysics*. **355**. [Bibcode](/source/Bibcode_(identifier)):[2000A&A...355L..27H](https://ui.adsabs.harvard.edu/abs/2000A&A...355L..27H).

1. **[^](#cite_ref-michigan_4-0)** Houk, N.; Smith-Moore, M. (1988). "Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26°.0 to -12°.0". *Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4*. **4**. [Bibcode](/source/Bibcode_(identifier)):[1988mcts.book.....H](https://ui.adsabs.harvard.edu/abs/1988mcts.book.....H).

1. ^ [***a***](#cite_ref-david_5-0) [***b***](#cite_ref-david_5-1) [***c***](#cite_ref-david_5-2) [***d***](#cite_ref-david_5-3) [***e***](#cite_ref-david_5-4) David, Trevor J.; Hillenbrand, Lynne A. (2015-05-01). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". *The Astrophysical Journal*. **804** (2): 146. [arXiv](/source/ArXiv_(identifier)):[1501.03154](https://arxiv.org/abs/1501.03154). [Bibcode](/source/Bibcode_(identifier)):[2015ApJ...804..146D](https://ui.adsabs.harvard.edu/abs/2015ApJ...804..146D). [doi](/source/Doi_(identifier)):[10.1088/0004-637X/804/2/146](https://doi.org/10.1088%2F0004-637X%2F804%2F2%2F146). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X). [Iota2 Librae's database entry](https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/ApJ/804/146&HIP=74493) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-tycho-gaia_6-0) [***b***](#cite_ref-tycho-gaia_6-1) [***c***](#cite_ref-tycho-gaia_6-2) McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01). ["Fundamental parameters and infrared excesses of Tycho-Gaia stars"](https://doi.org/10.1093%2Fmnras%2Fstx1433). *Monthly Notices of the Royal Astronomical Society*. **471**: 770–791. [arXiv](/source/ArXiv_(identifier)):[1706.02208](https://arxiv.org/abs/1706.02208). [doi](/source/Doi_(identifier)):[10.1093/mnras/stx1433](https://doi.org/10.1093%2Fmnras%2Fstx1433). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711). [Iota2 Librae's database entry](https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/MNRAS/471/770&RAJ2000=039.038607) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-simbad_7-0)** ["Iota2 Librae"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Iota2+Librae). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2024-06-15.

v t e Constellation of Libra List of stars in Libra Libra in Chinese astronomy Stars Bayer α1 α2 (Zubenelgenubi) β (Zubeneschamali) γ (Zubenelhakrabi) δ ε ζ1 ζ2 ζ3 ζ4 η θ ι1 ι2 κ λ μ ν ξ1 ξ2 ο σ (Brachium) τ υ Flamsteed 2 3 4 5 10 11 12 16 17 18 22 23 26 28 30 36 37 41 42 47 48 49 50 Variable HN HO KU KX HR 5504 5455 HD 133131 134439 134440 135485 137010 139139 140283 141569 141937 Other 2M1510 2MASS 1507−1627 CWISEP J1446−2317 HE 1523−0901 WASP-57 WISE 1534−1043 WISE 1541−2250 Exoplanets 23 Librae b c Gliese 581b c e HD 137010 b (unconfirmed) K2-315b WASP-189b Star clusters NGC 5897 Galaxies NGC 5597 5605 5716 5728 5792 5793 5861 5885 5890 5898 5915 5917 Other AP Librae IC 1059 IRAS 14348−1447 PKS 1510−089 PKS 1519−273 QSO B1524−136 RXC J1504.1−0248 BCG Category

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Adapted from the Wikipedia article [Iota2 Librae](https://en.wikipedia.org/wiki/Iota2_Librae) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Iota2_Librae?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.