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36 Ophiuchi
View on Wikipedia  36 Location of 36 Ophiuchi in the constellation Ophiuchus | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | A: 17h 15m 20.7836s[1] B: 17h 15m 20.9838s[2] C: 17h 16m 13.3624s[3] |
| Declination | A: −26° 36′ 06.117″[1] B: −26° 36′ 10.173″[2] C: −26° 32′ 46.137″[3] |
| Apparent magnitude (V) | 5.08/5.03/6.34[4] |
| Characteristics | |
| Spectral type | A: K2V[5] B: K1V[5] C: K5V[5] |
| Variable type | C: RS CVn |
| Astrometry | |
| 36 Oph A | |
| Radial velocity (Rv) | +0.26±0.12[1] km/s |
| Proper motion (μ) | RA: −498.600 mas/yr[1] Dec.: −1,149.158 mas/yr[1] |
| Parallax (π) | 168.0031±0.1343 mas[1] |
| Distance | 19.41 ± 0.02 ly (5.952 ± 0.005 pc) |
| 36 Oph B | |
| Radial velocity (Rv) | +0.10±0.13[4] km/s |
| Proper motion (μ) | RA: −465.861 mas/yr[2] Dec.: −1,141.168 mas/yr[2] |
| Parallax (π) | 168.1303±0.1081 mas[2] |
| Distance | 19.40 ± 0.01 ly (5.948 ± 0.004 pc) |
| 36 Oph C | |
| Radial velocity (Rv) | −0.07±0.12[3] km/s |
| Proper motion (μ) | RA: −479.573 mas/yr[3] Dec.: −1,124.332 mas/yr[3] |
| Parallax (π) | 167.9617±0.0311 mas[3] |
| Distance | 19.418 ± 0.004 ly (5.954 ± 0.001 pc) |
| Orbit[6] | |
| Primary | 36 Oph A |
| Companion | 36 Oph B |
| Period (P) | 470.9 yr |
| Semi-major axis (a) | 13″ |
| Eccentricity (e) | 0.916 |
| Inclination (i) | 99.8° |
| Details | |
| 36 Oph A | |
| Mass | 0.75+0.02 −0.04[7] M☉ |
| Radius | 0.817±0.016[8] R☉ |
| Luminosity | 0.326±0.084[9] L☉ |
| Temperature | 5,103±29[7] K |
| Metallicity [Fe/H] | −0.23[7] dex |
| Rotation | 20.69±0.40[10] days |
| Age | 1.43[10] Gyr |
| 36 Oph B | |
| Mass | 0.76+0.03 −0.06[11] M☉ |
| Radius | 0.721±0.044[12] R☉ |
| Luminosity | 0.32[11] L☉ |
| Surface gravity (log g) | 4.61[11] cgs |
| Temperature | 5,171±71[11] K |
| Metallicity [Fe/H] | −0.22[11] dex |
| Rotation | 21.11±0.40[10] days |
| Age | 1.43[10] Gyr |
| 36 Oph C | |
| Mass | 0.72±0.01[11] M☉ |
| Radius | 0.688±0.064[12] R☉ |
| Luminosity | 0.14[11] L☉ |
| Habitable zone inner limit | 0.32[13] AU |
| Habitable zone outer limit | 0.79[13] AU |
| Surface gravity (log g) | 4.70[11] cgs |
| Temperature | 4,474±22[11] K |
| Metallicity [Fe/H] | −0.22[11] dex |
| Rotation | 18.0±0.4[10] days |
| Age | 590±70[10] Myr |
| Other designations | |
| 36 Oph, WDS J17153-2636 | |
| AB: CD−26°12026, GJ 663, HIP 84405, PLX 3908.00 | |
| A: Guniibuu, HD 155886, HR 6402, SAO 185198, LHS 437 | |
| B: HD 155885, HR 6401, SAO 185199, LHS 438 | |
| C: 30 Sco, V2215 Oph, CD−26°12036, GJ 664, HD 156026, HIP 84478, SAO 185213, LHS 439, PLX 3913.00 | |
| Database references | |
| SIMBAD | AB |
| A | |
| B | |
| C | |
| Exoplanet Archive | B |
| C | |
| ARICNS | A |
| B | |
| C | |
36 Ophiuchi (or Guniibuu for component A) is a triple star system 19.5 light-years from Earth in the constellation Ophiuchus.
Nomenclature
[edit]36 Ophiuchi is the system's Flamsteed designation. Component C (HD 156026) was also historically called 30 Scorpii.[14]
In the culture of the Kamilaroi and Euahlayi Aboriginal peoples in New South Wales, Australia, the star is called Guniibuu and represents the robin red-breast bird (Petroica boodang).[15] In 2016, the IAU organized a Working Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN approved the name Guniibuu for 36 Ophiuchi A on 10 August 2018 and it is now so included in the List of IAU-approved Star Names.[15]
Characteristics
[edit]The primary and secondary stars (also known as HD 155886) are nearly identical orange main-sequence dwarfs of spectral type K2/K1. This binary is unusual because its eruptions do not seem to conform to the Waldmeier effect; that is, the strongest eruptions of HD 155886 are not the ones characterized by the fast eruption onset.[17]
The tertiary star is an orange main-sequence dwarf of spectral type K5. The age for this star derived using gyrochronology is about 600 million years, while the age derived for the AB pair is 1.43 billion years. This discrepancy suggest that the A/B stars interacted with each other and slowed down their rotation periods, providing a spuriously higher age.[10]
Star C is separated from the A-B pair by 700 arcseconds, compared to a minimum of 4.6 arcseconds for A-B, so its effect on the movements of the A-B pair is small. A and B have active chromospheres. At present the distance between the stars forming the AB-pair is 5.1 arcseconds and the position angle is 139 degrees, while star C is 731.6 arcseconds away from the A-component and situated at a position angle of 74 degrees.
Hunt for substellar objects
[edit]The McDonald Observatory team has set limits to the presence of one or more planets[19] around 36 Ophiuchi A with masses between 0.13 and 5.4 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical units (AU), although beyond 1.5 AU orbits are inherently unstable around either 36 Ophiuchi A or 36 Ophiuchi B.[20]
The star C (or namely HD 156026) is among five nearby paradigms as K-type stars of a type in a 'sweet spot’ between Sun-analog stars and M stars for the likelihood of evolved life, per analysis of Giada Arney from NASA's Goddard Space Flight Center.[21] It presents a significant difference on proper motion measurements taken by the Hipparcos and Gaia spacecrafts, suggesting the presence of a giant planet.[13]
Observation
[edit]On 26 October 2021, it was occulted by Venus as viewed from the Indian Ocean.[22]: 165
See also
[edit]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 d 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 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 "SIMBAD Astronomical Database". Centre de Données astronomiques de Strasbourg. Retrieved 2013-08-23.
- ^ 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.
- ^ Tokovinin, Andrei (July 2017). "Orbit Alignment in Triple Stars". The Astrophysical Journal. 844 (2): 103. arXiv:1706.00748. Bibcode:2017ApJ...844..103T. doi:10.3847/1538-4357/aa7746. ISSN 0004-637X.
- ^ a b c Luck, R. Earle (2017-01-01). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 21. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. ISSN 0004-6256.36 Ophiuchi A's database entry at VizieR.
- ^ Demory, Brice-Olivier; Ségransan, Damien; Forveille, Thierry; Queloz, Didier; Beuzit, Jean-Luc; Delfosse, Xavier; Di Folco, Emmanuel; Kervella, Pierre; Le Bouquin, Jean-Baptiste; Perrier, Christian; Benisty, Myriam; Duvert, Gilles; Hofmann, Karl-Heinz; Lopez, Bruno; Petrov, Romain (October 2009). "Mass-radius relation of low and very low-mass stars revisited with the VLTI". Astronomy and Astrophysics. 505 (1): 205–215. arXiv:0906.0602. Bibcode:2009A&A...505..205D. doi:10.1051/0004-6361/200911976. S2CID 14786643.
- ^ Hardegree-Ullman, Kevin K.; Apai, Dániel; Bergsten, Galen J.; Pascucci, Ilaria; López-Morales, Mercedes (2023-06-01). "Bioverse: A Comprehensive Assessment of the Capabilities of Extremely Large Telescopes to Probe Earth-like O2 Levels in Nearby Transiting Habitable-zone Exoplanets". The Astronomical Journal. 165 (6): 267. arXiv:2304.12490. Bibcode:2023AJ....165..267H. doi:10.3847/1538-3881/acd1ec. ISSN 0004-6256. 36 Ophiuchi A's database entry at VizieR.
- ^ a b c d e f g Otani, Tomomi; von Hippel, Ted; Buzasi, Derek; Oswalt, T. D.; Stone-Martinez, Alexander; Majewski, Patrice (2022-05-01). "A Monte Carlo Method for Evaluating Empirical Gyrochronology Models and Its Application to Wide Binary Benchmarks". The Astrophysical Journal. 930 (1): 36. arXiv:2105.07266. Bibcode:2022ApJ...930...36O. doi:10.3847/1538-4357/ac6035. ISSN 0004-637X.
- ^ a b c d e f g h i j Luck, R. Earle (2018-03-01). "Abundances in the Local Region. III. Southern F, G, and K Dwarfs". The Astronomical Journal. 155 (3): 111. Bibcode:2018AJ....155..111L. doi:10.3847/1538-3881/aaa9b5. ISSN 0004-6256. Database entries at VizieR:
36 Ophiuchi B
36 Ophiuchi C - ^ a b Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; De Lee, Nathan; Collins, Kevin; Latham, David W.; Muirhead, Philip S.; Chittidi, Jay; Rojas-Ayala, Bárbara; Fleming, Scott W.; Rose, Mark E.; Tenenbaum, Peter; Ting, Eric B. (2019-10-01). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Database entries at VizieR:36 Oph B
36 Oph C - ^ a b c Painter, Katie E.; Bowler, Brendan P.; Franson, Kyle; Becker, Juliette C.; Burt, Jennifer A. (2025-06-26). "Astrometric Accelerations of Provisional Targets for the Habitable Worlds Observatory". The Astronomical Journal. 170 (3): 147. arXiv:2506.21768. Bibcode:2025AJ....170..147P. doi:10.3847/1538-3881/ade442.
- ^ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy. 18 (3): 211. Bibcode:1987JHA....18..209W. doi:10.1177/002182868701800305. S2CID 118445625.
- ^ a b "IAU Catalog of Star Names". Retrieved 20 November 2025.
- ^ "IAU Working Group on Star Names (WGSN)". Archived from the original on 10 June 2016. Retrieved 17 September 2018.
- ^ Garg, Suyog; Karak, Bidya Binay; Egeland, Ricky; Soon, Willie; Baliunas, Sallie (2019). "Waldmeier Effect in Stellar Cycles". The Astrophysical Journal. 886 (2): 132. arXiv:1909.12148. Bibcode:2019ApJ...886..132G. doi:10.3847/1538-4357/ab4a17. S2CID 202888617.
- ^ "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
- ^ Wittenmyer, R. A.; Endl, Michael; Cochran, William D.; Hatzes, Artie P.; Walker, G. A. H.; Yang, S. L. S. & Paulson, Diane B. (2006). "Detection Limits from the McDonald Observatory Planet Search Program". Astronomical Journal. 132 (1): 177–188. arXiv:astro-ph/0604171. Bibcode:2006AJ....132..177W. doi:10.1086/504942. S2CID 16755455.
- ^ Irwin, Alan W.; Yang, Stephenson L. S. & Walker, Gordon A. H. (1996). "36 Ophiuchi AB: Incompatibility of the Orbit and Precise Radial Velocities". Publications of the Astronomical Society of the Pacific. 108: 580. Bibcode:1996PASP..108..580I. doi:10.1086/133768.
- ^
Bill Steigerwald (2019-03-07). ""Goldilocks" Stars May Be "Just Right" for Finding Habitable Worlds". NASA. Retrieved 2020-05-12.
'I find that certain nearby K stars like 61 Cyg A/B, Epsilon Indi, Groombridge 1618, and HD 156026 may be particularly good targets for future biosignature searches,' said Arney.
- ^ Meeus, Jan (2002). "Mutual occultations of planets". More Mathematical Astronomy Morsels (PDF). Willmann-Bell. pp. 174–185. ISBN 0943396743. Archived from the original (PDF) on 2025-04-05. Retrieved 2025-02-21.
Further reading
[edit]- Cayrel de Strobel, G.; Lebreton, Y.; Perrin, M.-N. & Cayrel, R. (1989). "A thorough spectroscopic study of the very nearby triple system - 36 Ophiuchi". Astronomy and Astrophysics. 225 (2): 369–380. Bibcode:1989A&A...225..369C.
- Barnes, Sydney A. (2007). "Ages for Illustrative Field Stars Using Gyrochronology: Viability, Limitations, and Errors". The Astrophysical Journal. 669 (2): 1167–1189. arXiv:0704.3068. Bibcode:2007ApJ...669.1167B. doi:10.1086/519295. S2CID 14614725.
External links
[edit]- "36 Ophiuchi". SolStation. Archived from the original on August 24, 2000. Retrieved 3 November 2005.
