# HIP 72217

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/HIP_72217
> Markdown URL: https://mediated.wiki/source/HIP_72217.md
> Source: https://en.wikipedia.org/wiki/HIP_72217
> Source revision: 1324902178
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Triple star system in the constellation Libra

HIP 72217 Observation data Epoch J2000 Equinox ICRS Constellation Libra[1] AB Right ascension 14h 46m 10.811s[2] Declination −21° 10′ 35.05″[2] Apparent magnitude (V) 6.43±0.01[3] (7.06 + 7.33)[1] C Right ascension 14h 46m 11.349s[4] Declination −21° 10′ 36.04″[4] Apparent magnitude (V) 16.82[1] Characteristics Evolutionary stage subgiant + subgiant + main sequence[1] Spectral type G1V[5] B−V color index 0.603[1] Astrometry AB Radial velocity (Rv) −1.9±0.4[6] km/s Proper motion (μ) RA: −57.28 mas/yr[7] Dec.: −101.60 mas/yr[7] Parallax (π) 24.24±0.63 mas[7] Distance 135 ± 3 ly (41 ± 1 pc) Absolute magnitude (MV) +3.35[8] C Proper motion (μ) RA: −71.95 mas/yr[4] Dec.: −108.23 mas/yr[4] Parallax (π) 24.8360±0.1337 mas[4] Distance 131.3 ± 0.7 ly (40.3 ± 0.2 pc) Orbit[1] Primary A Name B Period (P) 12.9170±0.0012 years Semi-major axis (a) 0.1854±0.0003" (7.65 au[a]) Eccentricity (e) 0.6319±0.0012 Inclination (i) 25.29±0.31° Longitude of the node (Ω) 277.42±0.96° Periastron epoch (T) 1995.2607±0.0022 Argument of periastron (ω) (secondary) 44.42±0.91° Semi-amplitude (K1) (primary) 7.06±0.00 km/s Semi-amplitude (K2) (secondary) 7.32±0.00 km/s Details[1] A Mass 1.14±0.15 M☉ Radius 1.47±0.04 R☉ Luminosity 2.73±0.19 L☉ Habitable zone inner limit 1.223 au Habitable zone outer limit 2.847 au Surface gravity (log g) 4.14±0.11 cgs Temperature 6,125±50 K Age 3.55±0.30 Gyr B Mass 1.12±0.14 M☉ Radius 1.39±0.03 R☉ Luminosity 2.21±0.14 L☉ Habitable zone inner limit 1.108 au Habitable zone outer limit 2.599 au Surface gravity (log g) 4.20±0.12 cgs Temperature 5,950±50 K Age 3.55±0.30 Gyr C Mass 0.17±0.01 M☉ Radius 0.28±0.01 R☉ Luminosity 0.0070±0.0002 L☉ Surface gravity (log g) 4.76±0.17 cgs Temperature 3,250±50 K Age 3.55±0.30 Gyr Other designations BD−20°4087, HD 129980, HIP 72217, HR 5504, TYC 6166-454-1[9] Database references SIMBAD data C

**HIP 72217** is a [triple star](/source/Triple_star) system in the constellation Libra. With an [apparent visual magnitude](/source/Apparent_visual_magnitude) of 6.43, it is very close to the limit for [naked eye](/source/Naked_eye) vision, and thus can only be seen in [dark skies](/source/Dark-sky_preserve). Based on [parallax](/source/Parallax) measurements, it lies at a distance of roughly 130 [light-years](/source/Light-year) (40 [parsecs](/source/Parsec)).

## Characteristics

This system is in a hierarchical configuration, with an inner pair of stars and an outer circumbinary component.

The two inner components A and B are [G-type](/source/G-type_star) stars that have reached the [subgiant](/source/Subgiant) stage of evolution and are larger, hotter and more luminous than the Sun. The stars take 12.917 years (4,718 days) to fully orbit each other, have a [semi-major axis](/source/Semi-major_axis) of 7.65 [astronomical units](/source/Astronomical_unit) (au) and are in an [eccentric orbit](/source/Eccentric_orbit) with *e* = 0.6319.[1]

Any planet orbiting either of the two inner stars would need to have an orbit between 0.003 and 0.067 au, since a longer orbit would be unstable due to the [gravitational perturbations](/source/Gravitational_perturbation) of the binary system, while a shorter orbit would reach the [Roche lobe](/source/Roche_lobe). A [circumbinary planet](/source/Circumbinary_planet) would need to be orbiting between 2.734 and 2.966 au. Meanwhile, the [habitable zone](/source/Habitable_zone) spans from roughly 1.2 to 2.8 au for the star A, and 1.1 to 2.6 au for the star B.[1]

The outer component C is a [red dwarf](/source/Red_dwarf) separated by 290 au from the inner pair.[b] It has around 28% of the Sun's size, shining with less than 1% of the Sun's luminosity and having an [effective temperature](/source/Effective_temperature) of 3,250 K.[1]

## Notes

1. **[^](#cite_ref-separationA-B_9-0)** Calculated using the [parallax](/source/Parallax) of 0.02424 [arcseconds](/source/Arcsecond) and the separation of 0.1854 arcseconds. 0.1854" / 0.02424" = 7.65 [au](/source/Astronomical_unit).

1. **[^](#cite_ref-separationAB-C_11-0)** Calculated using the [parallax](/source/Parallax) of 0.02424 [arcseconds](/source/Arcsecond) and the separation of 6.923 arcseconds. 6.923" / 0.02424" = 286 [au](/source/Astronomical_unit).

## References

1. ^ [***a***](#cite_ref-Nazar2025_1-0) [***b***](#cite_ref-Nazar2025_1-1) [***c***](#cite_ref-Nazar2025_1-2) [***d***](#cite_ref-Nazar2025_1-3) [***e***](#cite_ref-Nazar2025_1-4) [***f***](#cite_ref-Nazar2025_1-5) [***g***](#cite_ref-Nazar2025_1-6) [***h***](#cite_ref-Nazar2025_1-7) [***i***](#cite_ref-Nazar2025_1-8) [***j***](#cite_ref-Nazar2025_1-9) Nazar, Naufa; Al-Wardat, Mashhoor A.; Abushattal, Ahmad; Haboubi, Hassan B. (30 October 2025). "Stellar Parameters and Evolutionary Pathways of the Subgiant system HIP 72217". [arXiv](/source/ArXiv_(identifier)):[2510.26224](https://arxiv.org/abs/2510.26224) [[astro-PH](https://arxiv.org/archive/astro-PH)].

1. ^ [***a***](#cite_ref-DR3-AB_2-0) [***b***](#cite_ref-DR3-AB_2-1) 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%3D6280555385889024512%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-Fabricius2002_3-0)** Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". *Astronomy and Astrophysics*. **384**: 180. [Bibcode](/source/Bibcode_(identifier)):[2002A&A...384..180F](https://ui.adsabs.harvard.edu/abs/2002A&A...384..180F). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20011822](https://doi.org/10.1051%2F0004-6361%3A20011822).

1. ^ [***a***](#cite_ref-DR3-C_4-0) [***b***](#cite_ref-DR3-C_4-1) [***c***](#cite_ref-DR3-C_4-2) [***d***](#cite_ref-DR3-C_4-3) 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%3D6280555385887989504%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-Abt1981_5-0)** Abt, H. A. (1981). "Visual multiples. VII. MK classifications". *The Astrophysical Journal Supplement Series*. **45**: 437. [Bibcode](/source/Bibcode_(identifier)):[1981ApJS...45..437A](https://ui.adsabs.harvard.edu/abs/1981ApJS...45..437A). [doi](/source/Doi_(identifier)):[10.1086/190719](https://doi.org/10.1086%2F190719).

1. **[^](#cite_ref-rv_6-0)** Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". *Astronomy Letters*. **32** (11): 759. [arXiv](/source/ArXiv_(identifier)):[1606.08053](https://arxiv.org/abs/1606.08053). [Bibcode](/source/Bibcode_(identifier)):[2006AstL...32..759G](https://ui.adsabs.harvard.edu/abs/2006AstL...32..759G). [doi](/source/Doi_(identifier)):[10.1134/S1063773706110065](https://doi.org/10.1134%2FS1063773706110065).

1. ^ [***a***](#cite_ref-hipparcos_7-0) [***b***](#cite_ref-hipparcos_7-1) Van Leeuwen, F.; Al-Wardat, Mashhoor A.; Abushattal, Ahmad; Haboubi, Hassan B. (2007). "Validation of the new Hipparcos reduction". *Astronomy and Astrophysics*. **474** (2): 653. [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).

1. **[^](#cite_ref-xhip_8-0)** 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=72217&-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. **[^](#cite_ref-SIMBAD_10-0)** ["HD 129980"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+129980). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 28 November 2025.

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

---
Adapted from the Wikipedia article [HIP 72217](https://en.wikipedia.org/wiki/HIP_72217) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/HIP_72217?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.