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γ Ceti

Location of γ Ceti (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cetus
Right ascension	02 43 18.03910
Declination	+03° 14′ 08.9390″
Apparent magnitude (V)	3.47 (3.56/6.63/10.16)
Characteristics
Spectral type	A3 V + F3 V + K5
U−B color index	+0.07
B−V color index	+0.09
Astrometry
Radial velocity (Rv)	–5.1 km/s
Proper motion (μ)	RA: –146.10 mas/yr Dec.: –146.12 mas/yr
Parallax (π)	40.97 ± 0.63 mas
Distance	80 ± 1 ly (24.4 ± 0.4 pc)
Absolute magnitude (MV)	+1.53
Details
γ Cet A
Mass	1.88 M☉
Radius	1.9 R☉
Luminosity	21 L☉
Surface gravity (log g)	4.3 cgs
Temperature	8,551 K
Metallicity	0.00 dex
Rotational velocity (v sin i)	186 km/s
Age	647 Myr
γ Cet B
Mass	1.17 M☉
Temperature	6,051 K
Rotational velocity (v sin i)	10 km/s
Other designations
Kaffaljidhma, γ Cet, 86 Ceti, BD+02 422, HD 16970, HIP 12706, HR 804, SAO 110707, WDS 02433+0314
Database references
SIMBAD	Gamma Ceti system
	A
	B
	C

Gamma Ceti (γ Ceti, abbreviated Gamma Cet, γ Cet) is a triple star system in the equatorial constellation of Cetus. It has a combined apparent visual magnitude of 3.47. Based upon parallax measurements, this star is located at a distance of about 80 light-years (24.4 parsecs) from the Sun.

The three components are designated Gamma Ceti A (officially named Kaffaljidhma /ˌkæfəlˈdʒɪdmə/, the traditional name for the entire system), B and C.

Nomenclature

γ Ceti (Latinised to Gamma Ceti) is the system's Bayer designation. The designations of the three components as Gamma Ceti A, B and C derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). The close pair AB is also designated HIP 12706, HD 16970, and HR 804. The system of A, B, and C is collectively designated GJ 106.1 in the Gliese Catalogue of Nearby Stars.

Gamma Ceti bore the traditional names of Al Kaff al Jidhmah or Kaffaljidhma, derived from Arabic: الكف الجذماء al-kaf al-jaðmāʾ ('the cut-short hand'). According to a 1971 NASA memorandum, Al Kaff al Jidhmah was originally the title for five stars: Gamma Ceti as Kafaljidma, Xi Ceti as Al Kaff al Jidhmah I, Xi Ceti as Al Kaff al Jidhmah II, Delta Ceti as Al Kaff al Jidhmah III and Mu Ceti as Al Kaff al Jidhmah IV (excluding Alpha Ceti and Lambda Ceti). The IAU Working Group on Star Names (WGSN) approved the name Kaffaljidhma for the component Gamma Ceti A on February 1, 2017.

In Chinese astronomy, 天囷 Tiān Qūn, meaning 'Circular Celestial Granary', refers to an asterism consisting of Gamma Ceti, Alpha Ceti, Kappa Ceti, Lambda Ceti, Mu Ceti, Xi Ceti, Xi Ceti, Nu Ceti, Delta Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Gamma Ceti itself is 天囷八 Tiān Qūn bā ('the Eighth Star of Circular Celestial Granary').

Triple system

Gamma Ceti appears to be a triple star system. The inner pair (A and B) have an angular separation of 2.6 arcseconds. The primary component of this pair (A) is an A-type main sequence star with a stellar classification of A3 V and a visual magnitude of 3.6. The fainter secondary component (B) is an F-type main sequence star that has a classification of F3 V and a magnitude of 6.6. The contrasting colors of these two stars makes them a popular target of amateur astronomers. The two can be resolved with a small, 4 in (10 cm) aperture telescope under ideal seeing conditions, although at times they can be a challenge to resolve even with a much larger scope.

At a wide separation of 840 arcseconds is component C, a dim, magnitude 10.2 K-type star with the designation BD+02 418. It shares a common proper motion with A and is at a very similar distance, but is separated from the close pair by over 20,000 au. It has a spectral classification of K5V. There are several other stars brighter and closer to Gamma Ceti than BD+02 418 – BD+02 419, HD 16985, and TYC 50-1274-1 – but they are all more distant background stars.

Properties

The measured angular diameter of the primary star is 0.74 ± 0.08 mas. At the estimated distance of this system, this yields a physical size of about 1.9 times the radius of the Sun. The secondary component of this system is an X-ray source with a luminosity of 2.2 × 10 erg s. Gamma Ceti is about 300 million years old, and it appears to be a member of the stream of stars loosely associated with the Ursa Major Moving Group. The primary has been examined for an excess of infrared emission that would suggest the presence of circumstellar matter, but none was found.

References

1. ^ van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
2. ^ Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (1): 99–110. Bibcode:1966CoLPL...4...99J.
3. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
4. Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
5. ^ Anderson, E.; Francis, Ch. (25 May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
6. ^ Tokovinin, A.; Kiyaeva, O. (21 February 2016). "Eccentricity distribution of wide binaries". Monthly Notices of the Royal Astronomical Society. 456 (2): 2070–2079. arXiv:1512.00278. Bibcode:2016MNRAS.456.2070T. doi:10.1093/mnras/stv2825.
7. ^ Lang, Kenneth R. (February 2006). Astrophysical Formulae: Volume I & Volume II: Radiation, Gas Processes and High Energy Astrophysics/Space, Time, Matter and Cosmology. Astronomy and Astrophysics Library. Vol. 1 (3 ed.). Springer Science & Business Media. p. 41. ISBN 978-3-540-29692-8.
   The radius (R_*) is given by:

   ${\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(24.4\cdot 0.74\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 3.88\cdot R_{\bigodot }\end{aligned}}}$

8. ^ Gullikson, Kevin; Kraus, Adam; Dodson-Robinson, Sarah (26 July 2016). "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars". The Astronomical Journal. 152 (2): 40–53. arXiv:1604.06456. Bibcode:2016AJ....152...40G. doi:10.3847/0004-6256/152/2/40. S2CID 119179065.
9. Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Robinson, P. E. (11 July 2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I". The Astronomical Journal. 126 (4): 2048–2059. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365.
10. Royer, F.; Zorec, J.; Gómez, A. E. (February 2007). "Rotational velocities of A-type stars: III. Velocity distributions". Astronomy and Astrophysics. 463 (2): 671–682. arXiv:astro-ph/0610785. Bibcode:2007A&A...463..671R. doi:10.1051/0004-6361:20065224. S2CID 18475298.
11. "gam Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-03-04.
12. ^ "Naming Stars". International Astronomical Union. Archived from the original on 2017-12-22. Retrieved 16 December 2017.
13. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (3 December 2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 .
14. Allen, Richard Hinckley (1963) . Star Names: Their Lore and Meaning. New York, NY: Dover Publications. p. 160. ISBN 0-486-21079-0 – via LacusCurtius.
15. Rhoads, Jack W. (15 November 1971). Technical Memorandum 33-507: A reduced star catalog containing 537 named stars (PDF). Jet Propulsion Laboratory (Report). NASA. NASA-CR-124573. Archived from the original (PDF) on 2019-06-12. Retrieved 2018-02-03.
16. "Division C WG Star Names". International Astronomical Union. Archived from the original on 2017-08-02. Retrieved 2017-04-01.
17. 陳冠中; 陳輝樺 (11 July 2006). "中國古代的星象系統 (72): 胃宿天區". AEEA 天文教育資訊網 [AEEA (Activities of Exhibition and Education in Astronomy)] (in Chinese). National Museum of Natural Science. Archived from the original on 2020-10-02.
18. ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I. (2 October 2008). "Washington Double Star Catalog". United States Naval Observatory. Archived from the original on 14 February 2011. Retrieved 2 January 2018.
19. Mollise, Rod (May 2006). The Urban Astronomer's Guide: A Walking Tour of the Cosmos for City Sky Watchers. The Patrick Moore Practical Astronomy Series. Springer Science & Business Media. p. 200. ISBN 978-1-84628-216-4.
20. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
21. Dhital, Saurav; West, Andrew A.; Stassun, Keivan G.; Bochanski, John J. (7 May 2010). "Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs". The Astronomical Journal. 139 (6): 2566–2586. arXiv:1004.2755. Bibcode:2010AJ....139.2566D. doi:10.1088/0004-6256/139/6/2566. hdl:1721.1/93136. S2CID 661494.
22. Stephenson, C. B. (July 1986). "Dwarf K and M stars of high proper motion found in a hemispheric survey". The Astronomical Journal. 92: 139–165. Bibcode:1986AJ.....92..139S. doi:10.1086/114146.
23. Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005). "CHARM2: An updated Catalog of High Angular Resolution Measurements". Astronomy and Astrophysics. 431 (2): 773–777. Bibcode:2005A&A...431..773R. doi:10.1051/0004-6361:20042039.
24. Schröder, C.; Schmitt, J. H. M. M. (November 2007). "X-ray emission from A-type stars". Astronomy and Astrophysics. 475 (2): 677–684. Bibcode:2007A&A...475..677S. doi:10.1051/0004-6361:20077429.
25. ^ Su, K. Y. L.; et al. (December 2006). "Debris Disk Evolution around A Stars". The Astrophysical Journal. 653 (1): 675–689. arXiv:astro-ph/0608563. Bibcode:2006ApJ...653..675S. doi:10.1086/508649. S2CID 14116473.
26. King, Jeremy R.; Villarreal, Adam R.; Soderblom, David R.; Gulliver, Austin F.; Adelman, Saul J. (April 2003). "Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group". The Astronomical Journal. 125 (4): 1980–2017. Bibcode:2003AJ....125.1980K. doi:10.1086/368241 – via TigerPrints.

External links

• Information about Kaffaljidhma on STARS
• Gamma Ceti on AAS WorldWide Telescope

v t e Constellation of Cetus
List of stars in Cetus Cetus in Chinese astronomy
Stars	Bayer α (Menkar) β (Diphda) γ (Kaffaljidhma) δ ε ζ (Baten Kaitos) η θ ι κ κ λ μ ν ξ ξ ο (Mira) A B π ρ σ τ υ φ φ φ φ χ Flamsteed 1 2 3 6 7 9 13 14 20 46 49 56 (υ) 63 64 69 75 77 79 81 84 94 25 Ari Variable T UV YZ ZZ AY BL BW DK HR 10 72 159 228 500 672 870 HD 984 1690 2638 4747 5319 6718 7449 11506 11964 15115 16008 224693 (Axólotl) Other 2MASS J01225093−2439505 BD-07 436 BD−17 63 (Felixvarela) Cayrel's Star CFBDS J005910.90–011401.3 DENIS-P J020529.0−115925 GD 40 Gliese 65 Gliese 105 GJ 1002 GJ 1005 HIP 5158 HIP 11952 LHS 1140 NGC 156 NGC 158 NGC 302 NGC 308 NGC 310 PSR J0108−1431 SDSS J001820.5−093939.2 SDSS J0106−1000 ULAS J003402.77−005206.7 WD J2356−209 WASP-20 WASP-26 WASP-44 WASP-71 (Mpingo) WISE J0254+0223 WHL0137-LS
Exoplanets 79 Ceti b 81 Ceti b 94 Ceti b BD−17 63 b HD 1461 b HD 2638 b HD 5319 b HD 11506 b c HD 11964 b c HD 224693 b HIP 5158 b c HIP 11915 b τ Ceti e f
Nebulae NGC 246
Galaxies	Messier 77 NGC 17 35 45 47 50 54 59 61 62 64 65 66 73 77 102 107 113 114 116 117 118 120 124 132 135 142 143 144 145 151 154 155 157 161 163 165 166 167 168 170 171 172 173 177 178 179 187 191 192 195 196 197 201 207 209 210 216 217 219 223 227 230 232 235 237 239 244 245 247 255 259 263 268 270 271 273 274 275 276 277 279 283 284 285 286 291 293 297 298 301 303 307 309 320 321 325 327 329 331 333 335 336 337 340 341 342 343 344 345 347 349 350 351 352 353 355 356 357 359 363 364 367 369 377 391 413 417 426 428 429 430 435 442 445 448 450 478 480 481 487 493 497 519 521 533 540 541 545 547 554 555 560 570 584 585 596 615 622 655 681 682 690 701 720 747 755 779 800 806 833 838 864 874 880 895 908 936 945 950 960 965 966 985 988 1009 1015 1019 1022 1032 1042 1052 1055 1073 1087 1090 1128 1142 1153 1218 7808 7828 7829 Other Arp 146 Arp 147 Arp 256 3C 75 Cetus Dwarf HCM-6A HD2 Holmberg 15A HXMM01 IC 1613 IC 1623 IRAS 01003-2238 Markarian 1014 Markarian 1018 MCG -03-04-014 PGC 2456 SDSS J0303-0019 SXDF-NB1006-2 9Spitch TON S180 UGC 711 UGC 1775 Wolf–Lundmark–Melotte
Galaxy clusters Abell 133 Abell 222 Abell 223 Abell 370 Abell 400 Arp 251 Gioiello IRC 0218 JKCS 041
Astronomical events SN 2005E SN 2005gj
Category

• Cetus
• Bayer objects
• Stars with proper names
• Flamsteed objects
• A-type main-sequence stars
• F-type main-sequence stars
• K-type main-sequence stars
• Hipparcos objects
• Henry Draper Catalogue objects
• Bright Star Catalogue objects
• Durchmusterung objects