HD 102365

Last updated
HD 102365
Observation data
Epoch J2000       Equinox J2000
Constellation Centaurus [1]
A
Right ascension 11h 46m 31.07253s [2]
Declination −40° 30′ 01.2859″ [2]
Apparent magnitude  (V)4.88 [3]
B
Right ascension 11h 46m 32.68988s [4]
Declination −40° 29′ 47.6048″ [4]
Apparent magnitude  (V)15 [5]
Characteristics
Spectral type G2V [6] + M4V [7]
U−B color index 0.10 [3]
B−V color index 0.67 [3]
Astrometry
A
Radial velocity (Rv)16.94±0.12 [2] km/s
Proper motion (μ)RA: −1530.971 mas/yr [2]
Dec.: +403.287 mas/yr [2]
Parallax (π)107.3024±0.0873  mas [2]
Distance 30.40 ± 0.02  ly
(9.319 ± 0.008  pc)
Absolute magnitude  (MV)5.07 [8]
B
Radial velocity (Rv)17.23±0.27 [4] km/s
Proper motion (μ)RA: −1534.679 mas/yr [4]
Dec.: +381.396 mas/yr [4]
Parallax (π)107.4237±0.0351  mas [4]
Distance 30.362 ± 0.010  ly
(9.309 ± 0.003  pc)
Details
A
Mass 0.79+0.03
−0.02 [9]   M☉
Radius 0.99±0.02 [10]   R☉
Luminosity 0.86±0.05 [10]   L☉
Habitable zone inner limit0.887 [9] AU
Habitable zone outer limit1.573 [9] AU
Surface gravity (log g)4.44±0.03 [10]   cgs
Temperature 5,594+49
−50 [10]   K
Metallicity [Fe/H]−0.34±0.04 [9]   dex
Rotation 36.4±7.3 [9] days
Rotational velocity (v sin i)0.5 [11]  km/s
Age 11.0±0.9 [12]   Gyr
B
Mass 0.192 [13]   M☉
Other designations
66 G. Cen, CD−39°7301, GJ 442, HD 102365, HIP 57443, HR 4523, SAO 223020, LHS 311, LTT 4373, PLX 2725.00 [14] [15]
B: LHS 313, VB 5
Database references
SIMBAD A
B
Exoplanet Archive data
ARICNS data

HD 102365 (66 G. Centauri) is a binary star system that is located in the northeastern part of the Centaurus constellation, at a distance of about 30.4 light-years (9.3 parsecs ) from the Solar System. The larger member of the system is a G-type star that is smaller than the Sun but of similar mass. It has a common proper motion companion that was discovered by W. J. Luyten in 1960. [7] This M-type star appears to be in a wide orbit around the primary at a current separation of about 211 astronomical units (AU), [7] (or 211 times the separation of the Earth from the Sun). By comparison, Neptune orbits at an average distance of 30 AU.

Contents

Description

The stellar classification for the primary star in this system is G2V; [6] the same as the Sun. That of the red dwarf companion is M4V. [7] The primary star has an estimated 84% the mass of the Sun, 99% of the Sun's radius, and 86% of the Sun's luminosity. [10] It is a slow rotator, with a projected rotational velocity of 0.5 km/s. [11] The system is believed to be ancient, with modern estimates of the age between 11.0 [12] and 13.1 billion years, [16] over double that of the Solar System. Compared to the Sun, it only has about 52% of the abundance of elements other than hydrogen and helium; what astronomers term the metallicity of a star. [17]

This star system has a relatively large proper motion. [14] The HR 4523 system is presently located within the Epsilon Indi Moving Group, although it gives itself away as an interloper, since the star is older and has a different composition than the group members. [18] It has space velocity components [U, V, W] = [−67, −40, +4] km/s. [19]

Search for planets

The primary star has been believed to be orbited by a Neptune-like planet with a minimum mass 9.3 times that of the Earth. [20] The orbital period of this planet is 122.1 days. No other planets have been discovered orbiting this star. [21] Initially detected in 2012 by Doppler spectroscopy (radial velocity method), [21] a 2013 study was unable to confirm this planet, [22] but it was detected again in a 2023 study. Evidence suggested the radial velocity variations are indeed caused from the orbital motion of a planet, and not from intrinsic processes arising from the star. [20] : 27  However, it was again undetected in ESPRESSO observations taken by a 2025 study, which found evidence that the radial velocity variations instead arise from the star's magnetic field. [9]

An examination of this system in the infrared did not reveal an excess emission that would otherwise suggest the presence of a circumstellar debris disk. [23]

The HD 102365 planetary system [20]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b(controversial [9] )≥9.34+1.52
−1.5 M🜨 		0.46±0.04121.3±0.250.28±0.15——

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific . 99 (617): 695. Bibcode:1987PASP...99..695R. doi: 10.1086/132034 . Constellation record for this object at VizieR.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 Feinstein, A. (1966), "Photoelectric observations of Southern late-type stars", The Information Bulletin for the Southern Hemisphere, 8: 30, Bibcode:1966IBSH....8...30F
  4. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  5. ↑ Poveda, A.; et al. (April 1994), "Statistical studies of visual double and multiple stars. II. A catalogue of nearby wide binary and multiple systems", Revista Mexicana de Astronomía y Astrofísica, 28 (1): 43–89, Bibcode:1994RMxAA..28...43P
  6. 1 2 Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv: astro-ph/0603770 , Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID   119476992
  7. 1 2 3 4 Raghavan, Deepak; et al. (September 2010), "A Survey of Stellar Families: Multiplicity of Solar-type Stars", The Astrophysical Journal Supplement, 190 (1): 1–42, arXiv: 1007.0414 , Bibcode:2010ApJS..190....1R, doi:10.1088/0067-0049/190/1/1, S2CID   368553 For the adopted physical separation, see Table 11 in the appendix.
  8. ↑ Holmberg, J.; Nordström, B.; Andersen, J. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv: 0811.3982 , Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID   118577511
  9. 1 2 3 4 5 6 7 Figueira, P.; Faria, J. P.; Silva, A. M.; Castro-González, A.; Silva, J. Gomes da; Sousa, S. G.; Bossini, D.; Zapatero-Osorio, M. R.; Balsalobre-Ruza, O. (2025-07-10), "A comprehensive study on radial velocity signals using ESPRESSO: Pushing precision to the 10 cm/s level", Astronomy and Astrophysics , arXiv: 2507.07514
  10. 1 2 3 4 5 Harada, Caleb K.; et al. (June 2024), "Setting the Stage for the Search for Life with the Habitable Worlds Observatory: Properties of 164 Promising Planet-survey Targets", The Astrophysical Journal Supplement Series, 272 (2), id. 30, arXiv: 2401.03047 , Bibcode:2024ApJS..272...30H, doi: 10.3847/1538-4365/ad3e81
  11. 1 2 Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi: 10.1051/0004-6361:200810377 [ permanent dead link ]
  12. 1 2 Nissen, P. E.; Christensen-Dalsgaard, J.; Mosumgaard, J. R.; Silva Aguirre, V.; Spitoni, E.; Verma, K. (August 2020), "High-precision abundances of elements in solar-type stars: Evidence of two distinct sequences in abundance-age relations", Astronomy & Astrophysics, 640: A81, doi:10.1051/0004-6361/202038300, ISSN   0004-6361
  13. ↑ Mugrauer, M. (December 2019), "Search for stellar companions of exoplanet host stars by exploring the second ESA-Gaia data release", Monthly Notices of the Royal Astronomical Society , 490 (4): 5088–5102, Bibcode:2019MNRAS.490.5088M, doi: 10.1093/mnras/stz2673
  14. 1 2 "HD 102365". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2011-10-11.
  15. ↑ Gould, Benjamin Apthorp (1879), "Uranometria Argentina catalog of bright southern stars", Resultados del Observatorio Nacional Argentino en Cordoba, 1, Buenos Aires, Bibcode:1879RNAO....1.....G , retrieved 2012-05-08
  16. ↑ Casali, G.; Spina, L.; Magrini, L.; Karakas, A. I.; Kobayashi, C.; Casey, A. R.; Feltzing, S.; Swaelmen, M. Van der; Tsantaki, M.; Jofré, P.; Bragaglia, A.; Feuillet, D.; Bensby, T.; Biazzo, K.; Gonneau, A. (2020-07-01), "The Gaia-ESO survey: the non-universality of the age–chemical-clocks–metallicity relations in the Galactic disc", Astronomy & Astrophysics, 639: A127, doi:10.1051/0004-6361/202038055, ISSN   0004-6361
  17. ↑ For a metallicity of [Fe/H] = −0.28 dex, the proportion of metals is given by 10−0.28, or 52%.
  18. ↑ Kovacs, N.; Foy, R. (1978), "A detailed analysis of three stars in the Eggen's Epsilon INDI moving group", Astronomy and Astrophysics, 68 (1–2): 27–31, Bibcode:1978A&A....68...27K
  19. ↑ Gliese, W. (1969), "Catalogue of Nearby Stars. Edition 1969", Veröffentlichungen des Astronomischen Rechen-Instituts Heidelberg, vol. 22, Karlsruhe, p. 1, Bibcode:1969VeARI..22....1G {{citation}}: CS1 maint: location missing publisher (link)
  20. 1 2 3 Laliotis, Katherine; Burt, Jennifer A.; et al. (February 2023), "Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions", The Astronomical Journal , 165 (4): 176, arXiv: 2302.10310 , Bibcode:2023AJ....165..176L, doi: 10.3847/1538-3881/acc067
  21. 1 2 Tinney, C. G.; et al. (2011), "The Anglo-Australian Planet Search. XX. A Solitary Ice-giant Planet Orbiting HD 102365", The Astrophysical Journal, 727 (2): 103, Bibcode:2011ApJ...727..103T, doi:10.1088/0004-637X/727/2/103, S2CID   54984338
  22. ↑ Zechmeister, M.; Kürster, M.; et al. (April 2013), "The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars", Astronomy & Astrophysics , 552: A78, arXiv: 1211.7263 , Bibcode:2013A&A...552A..78Z, doi:10.1051/0004-6361/201116551, S2CID   53694238
  23. ↑ Beichman, C. A.; et al. (December 2006), "New Debris Disks around Nearby Main-Sequence Stars: Impact on the Direct Detection of Planets", The Astrophysical Journal, 652 (2): 1674–1693, arXiv: astro-ph/0611682 , Bibcode:2006ApJ...652.1674B, doi:10.1086/508449, S2CID   14207148
  24. Takeda, Genya; et al. (February 2007), "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog", The Astrophysical Journal Supplement Series, 168 (2): 297–318, arXiv: astro-ph/0607235 , Bibcode:2007ApJS..168..297T, doi:10.1086/509763, S2CID   18775378
  25. Porto de Mello, G.; del Peloso, E. F.; Ghezzi, L. (2006), "Astrobiologically Interesting Stars Within 10 Parsecs of the Sun", Astrobiology, 6 (2): 308–331, arXiv: astro-ph/0511180 , Bibcode:2006AsBio...6..308P, doi:10.1089/ast.2006.6.308, PMID   16689649, S2CID   119459291
  26. Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv: 0807.1686 , Bibcode:2008ApJ...687.1264M, doi:10.1086/591785, S2CID   27151456
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