Astronomy:Gamma Ophiuchi
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 47m 53.55973s[1] |
| Declination | +02° 42′ 26.2000″[1] |
| Apparent magnitude (V) | +3.753[2] |
| Characteristics | |
| Spectral type | A0 V[3] or A1VnkA0mA0[4] |
| U−B color index | +0.040[2] |
| B−V color index | +0.033[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.6±0.3[5] km/s |
| Proper motion (μ) | RA: −24.64[1] mas/yr Dec.: −74.42[1] mas/yr |
| Parallax (π) | 31.73 ± 0.21[1] mas |
| Distance | 102.8 ± 0.7 ly (31.5 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.26[5] |
| Details | |
| Mass | 2.9[3] M☉ |
| Radius | 1.91[6] R☉ |
| Luminosity | 29[3] L☉ |
| Surface gravity (log g) | 4.03[4] cgs |
| Temperature | 9,506[3] K |
| Rotational velocity (v sin i) | 220[7] km/s |
| Age | 184+93 −134[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gamma Ophiuchi, Latinized from γ Ophiuchi, also named Bake-eo,[9] is a fourth-magnitude star in the constellation Ophiuchus. Together with Beta Ophiuchi, it forms the serpent-holder's right shoulder.[10] The star is visible to the naked eye with an apparent visual magnitude of +3.75.[2] Based upon an annual parallax shift of 31.73 mas as seen from Earth, it is located 103 light-years from the Sun. It is moving closer to the Sun with a radial velocity of −7.6 km/s.[5]
Nomenclature
This star is known also as Muliphen,[11][12] although at least two more stars are known with this name: Gamma Canis Majoris (often spelled as Muliphein) and Gamma Centauri (often spelled as Muhlifain).[12] Muliphein is the IAU-approved name of Gamma Canis Majoris.[9]
This star has the Marshallese name Bake-eo (or Bake Eo, pronounced "bakey-yew"), which refers to the spondylus mussel. The IAU Working Group on Star Names approved the name Bake-eo for this star on 20 August 2024 and it is now so entered in the IAU Catalog of Star Names.[9]
In Chinese astronomy, β Ophiuchi and γ Ophiuchi form the asterism Zongzheng (宗正),[13] which was transliterated as Tsung Ching by R. H. Allen.[11]
Description
![Image of the debris disk from the REASONS survey[14]](/wiki/File:The_74_exocomet_belts_imaged_by_ALMA%E2%80%99s_REASONS_survey,_showing_belts_of_all_shapes,_sizes_and_ages_(REASONS_comboplot_full_nonames).jpg)
This is an A-type main sequence star with a stellar classification of A0 V.[3] Gray et al. (2003) lists a classification of A1VnkA0mA0,[4] indicating it is of type A1 V with the calcium K-line and metallic lines of an A0 star. It is approximately 184[7] million years old and is spinning rapidly with a projected rotational velocity of 220 km/s.[7] Gamma Ophiuchi has nearly three times the mass of the Sun and 1.8 times the Sun's radius.[15] The star shines with 29[3] times the luminosity of the Sun, which is being emitted from its outer atmosphere at an effective temperature of 9506 K.[3] It is radiating an excess emission of infrared, suggesting the presence of a circumstellar disk of dust at an orbital radius of 64 AU from the host star.[3] The disk was imaged in 2025.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics 474 (2): 653–64. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Cousins, A. W. J. (1984). "Standardisation of broad band photometry of equatorial standards". South Africa Astronomical Observatory Circular 8: 59–67. Bibcode: 1984SAAOC...8...59C.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Wyatt, M. C. et al. (July 2007). "Steady State Evolution of Debris Disks around A Stars". The Astrophysical Journal 663 (1): 365–382. doi:10.1086/518404. Bibcode: 2007ApJ...663..365W.
- ↑ 4.0 4.1 4.2 Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (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. doi:10.1086/504637. Bibcode: 2006AJ....132..161G.
- ↑ 5.0 5.1 5.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ Rhee, Joseph H.; Song, Inseok; Zuckerman, B.; McElwain, Michael (May 2007). "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs" (in en). The Astrophysical Journal 660 (2): 1556–1571. doi:10.1086/509912. ISSN 0004-637X. Bibcode: 2007ApJ...660.1556R.
- ↑ 7.0 7.1 7.2 7.3 Song, Inseok et al. (February 2001). "Ages of A-Type Vega-like Stars from uvbyβ Photometry". The Astrophysical Journal 546 (1): 352–357. doi:10.1086/318269. Bibcode: 2001ApJ...546..352S.
- ↑ "* gam Oph". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+gam+Oph.
- ↑ 9.0 9.1 9.2 "IAU Catalog of Star Names". https://exopla.net/star-names/modern-iau-star-names/.
- ↑ Ridpath, Ian (June 28, 2018). Star Tales. Lutterworth Press. p. 189. ISBN 9780718847821. https://books.google.com/books?id=-dXYDwAAQBAJ&pg=PT189.
- ↑ 11.0 11.1 Hinckley Allen, Richard. "LacusCurtius • Allen's Star Names — Ophiuchus". https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Ophiuchus*.html.
- ↑ 12.0 12.1 Kaler, Jim. "Muliphen". http://stars.astro.illinois.edu/sow/muliphen.html.
- ↑ Ridpath, Ian. "Star Tales - Ophiuchus". http://ianridpath.com/startales/ophiuchus.html.
- ↑ 14.0 14.1 14.2 Matrà, L.; Marino, S.; Wilner, D. J.; Kennedy, G. M.; Booth, M.; Krivov, A. V.; Williams, J. P.; Hughes, A. M. et al. (January 2025). "REsolved ALMA and SMA Observations of Nearby Stars (REASONS): A population of 74 resolved planetesimal belts at millimetre wavelengths". Astronomy & Astrophysics 693: A151. doi:10.1051/0004-6361/202451397. Bibcode: 2025A&A...693A.151M.
- ↑ Malagnini, M. L.; Morossi, C. (November 1990). "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars". Astronomy and Astrophysics Supplement Series 85 (3): 1015–1019. Bibcode: 1990A&AS...85.1015M.
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