36 Ophiuchi
Coordinates: 
17h 15m 20.851s, −26° 36′ 09.04″
17h 15m 20.851s, −26° 36′ 09.04″ | This article needs additional citations for verification. (January 2021) |
| Observation data Epoch J2000 Equinox J2000 | ||
|---|---|---|
| Constellation | Ophiuchus | |
| Right ascension | A: 17h 15m 20.851s B: 17h 15m 20.978s C: 17h 16m 13.3624s[2] | |
| Declination | A: −26° 36′ 09.04″ B: −26° 36′ 10.18″ C: −26° 32′ 46.129″[2] | |
| Apparent magnitude (V) | 5.08/5.03/6.34[2] | |
| Characteristics | ||
| Spectral type | K2 V/K1 V/K5 V[2] | |
| U−B color index | 0.51(AB)/1.04 | |
| B−V color index | 0.85(AB)/1.16 | |
| Variable type | C: RS CVn | |
| 36 Oph C | ||
Distance | 19.418 ± 0.004 ly (5.954 ± 0.001 pc) | |
Periastron epoch (T) | 1,763.39 | |
| Details | ||
| 36 Oph A/B | ||
Gyr | ||
| 36 Oph C | ||
| Mass | 0.71 M☉ | |
| Radius | 0.72 R☉ | |
| Luminosity (bolometric) | 0.20[note 1] L☉ | |
| Luminosity (visual, LV) | 0.09 L☉ | |
| Temperature | 4,550 K | |
| Metallicity | 46–100% Sun | |
HIP 84478 | ||
| Database references | ||
Exoplanet Archive | A | |
| B | ||
| C | ||
| ARICNS | A | |
| B | ||
| C | ||
  36 Location of 36 Ophiuchi in the constellation Ophiuchus | ||
36 Ophiuchi (or Guniibuu for component A) is a triple star system 19.5 light-years from Earth. It is in the constellation Ophiuchus.
The primary and secondary stars (also known as HD 155886) are nearly identical orange
spectral type
K5.
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.
Nomenclature
In the beliefs of the
Working Group on Star Names (WGSN)[11] to catalog and standardize proper names for stars. The WGSN approved the name Guniibuu for the star A on 10 August 2018 and it is now so included in the List of IAU-approved Star Names.[12]
Hunt for substellar objects
The McDonald Observatory team has set limits to the presence of one or more planets[8] 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.[13]
The star C (or namely HD 156026) is among five nearby paradigms as
M stars for the likelihood of evolved life, per analysis of Giada Arney from NASA's Goddard Space Flight Center.[14]
In culture
In the Dune franchise, the fictional planet Giedi Prime, homeworld of the antagonistic House Harkonnen, orbits 36 Ophiuchi B.
Notes
- ^ Stefan–Boltzmann constant.
References
- ^ a b "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
- ^ Centre de Données astronomiques de Strasbourg. Retrieved 2013-08-23.
- ^ .
- ^ .
- ^ .
- ^ S2CID 14786643.
- ^
- ^ a b Wittenmeyer et al. (2006).
- S2CID 27151456
- S2CID 202888617
- ^ "IAU Working Group on Star Names (WGSN)". Retrieved 17 September 2018.
- ^ "IAU Catalog of Star Names". International Astronomical Union. Retrieved 2018-09-17.
- ^ Irwin et al. (1996).
- ^
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.
Further reading
- 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, doi:10.1086/133768
- 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
- Wittenmeyer, 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, S2CID 16755455
- Barnes, Sydney A. (2007), "Ages for Illustrative Field Stars Using Gyrochronology: Viability, Limitations, and Errors", The Astrophysical Journal, 669 (2): 1167–1189, S2CID 14614725
External links
- "36 Ophiuchi". SolStation. Retrieved 3 November 2005.
- https://arxiv.org/abs/astro-ph/0604171
