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.[6] This M-type star appears to be in a wide orbit around the primary at a current separation of about 211 astronomical units (AU),[6] (or 211 times the separation of the Earth from the Sun). By comparison, Neptune orbits at an average distance of 30 AU.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus |
| HD 102365 A | |
| Right ascension | 11h 46m 31.07253s[1] |
| Declination | −40° 30′ 01.2859″[1] |
| Apparent magnitude (V) | 4.88[2] |
| HD 102365 B | |
| Right ascension | 11h 46m 32.68988s[3] |
| Declination | −40° 29′ 47.6048″[3] |
| Apparent magnitude (V) | 15[4] |
| Characteristics | |
| Spectral type | G2V[5] + M4V[6] |
| U−B color index | 0.10[2] |
| B−V color index | 0.67[2] |
| Astrometry | |
| HD 102365 A | |
| Radial velocity (Rv) | 16.94±0.12[1] km/s |
| Proper motion (μ) | RA: −1530.971 mas/yr[1] Dec.: +403.287 mas/yr[1] |
| Parallax (π) | 107.3024 ± 0.0873 mas[1] |
| Distance | 30.40 ± 0.02 ly (9.319 ± 0.008 pc) |
| Absolute magnitude (MV) | 5.07[7] |
| HD 102365 B | |
| Radial velocity (Rv) | 17.23±0.27[3] km/s |
| Proper motion (μ) | RA: −1534.679 mas/yr[3] Dec.: +381.396 mas/yr[3] |
| Parallax (π) | 107.4237 ± 0.0351 mas[3] |
| Distance | 30.362 ± 0.010 ly (9.309 ± 0.003 pc) |
| Details | |
| A | |
| Mass | 0.889[8] M☉ |
| Radius | 0.96[8] R☉ |
| Luminosity | 0.85[9] L☉ |
| Surface gravity (log g) | 4.51[5] cgs |
| Temperature | 5,643[9] K |
| Metallicity [Fe/H] | −0.28[9] dex |
| Rotational velocity (v sin i) | 0.5[10] km/s |
| Age | 4.5–5.7[11] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | A |
| B | |
| ARICNS | data |
Description
editThe stellar classification for the primary star in this system is G2V;[5] the same as the Sun. That of the red dwarf companion is M4V.[6] The primary star has an estimated 86%[13] to 89% the mass of the Sun, 96% of the Sun's radius,[8] and 85% of the Sun's luminosity.[9] It is a slow rotator, with a projected rotational velocity of 0.5 km/s.[10] Age estimates range from 4.5 to 5.7 billion years (Gyr)[11] up to 7.1 Gyr[7] or 9.48 Gyr.[8] Compared to the Sun, it only has about 52%[14] of the abundance of elements other than hydrogen and helium; what astronomers term the metallicity of a star.
This star system has a relatively large proper motion.[12] 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.[15] It has space velocity components [U, V, W] = [−67, −40, +4] km/s.[16]
Planetary system
editThe primary star is believed to be orbited by a Neptune-like planet with a minimum mass 16 times that of the Earth. The orbital period of this planet is 122.1 days. No other planets have been discovered orbiting this star.[17] While a 2013 study was unable to confirm this planet,[18] it was confirmed by a 2023 study, with updated parameters.[19]: 27
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.[20]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥9.34+1.52 −1.5 M🜨 |
0.46±0.04 | 121.3±0.25 | 0.28±0.15 | — | — |
In popular culture
editThe couch gag for Bart's Not Dead in the television series The Simpsons has an alien family sitting on a couch in this star system. The adult male alien asks why Homer sounds like Walter Matthau.
References
edit- ^ a b c d e 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.
- ^ a b c Feinstein, A. (1966), "Photoelectric observations of Southern late-type stars", The Information Bulletin for the Southern Hemisphere, 8: 30, Bibcode:1966IBSH....8...30F
- ^ a b c d e 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.
- ^ 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
- ^ a b c 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
- ^ a b c d 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.
- ^ a b 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
- ^ a b c d 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
- ^ a b c d 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
- ^ a b 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]
- ^ a b 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
- ^ a b "HD 102365". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2011-10-11.
- ^ O'Toole, S. J.; et al. (August 2009), "The Frequency of Low-Mass Exoplanets", The Astrophysical Journal, 701 (2): 1732–1741, arXiv:0906.4619, Bibcode:2009ApJ...701.1732O, doi:10.1088/0004-637X/701/2/1732, S2CID 18041021
- ^ For a metallicity of [Fe/H] = −0.28 dex, the proportion of metals is given by 10−0.28, or 52%.
- ^ 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
- ^ 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) - ^ a b Tinney, C. G.; et al. (2011), "The Anglo-Australian Planet Search. XX. A Solitary Ice-giant Planet Orbiting HD 102365" (PDF), The Astrophysical Journal, 727 (2): 103, Bibcode:2011ApJ...727..103T, doi:10.1088/0004-637X/727/2/103, S2CID 54984338
- ^ 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.
- ^ a b 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.
- ^ 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
External links
edit- HR 4523 AB, SolStation, retrieved 2011-10-11