Mu Ceti (μ Ceti) is a binary star in the constellation Cetus, the whale, close to Pisces. The combined apparent magnitude of the system is +4.27, making it visible as a faint star from skies with low or no luminous pollution. Based upon parallax measurements taken by the Gaia spacecraft, it is located 87 light-years away.
The location of Mu Ceti next to the ecliptic make it succeptible to lunar occultations.[7]
Nomenclature
Mu Ceti is the system's Bayer designation. It has no official proper name.[8]
In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Mu Ceti itself is "the Fourth Star of Circular Celestial Granary".[9]
Characteristics
Mu Ceti is a spectroscopic binary. These systems have binarity inferred from variations in their spectral lines, which shift from redder to bluer (gravitational redshift) across the orbit. It has also been resolved by speckle interferometry. The energy output is dominated by the main star, which is 25 times brighter than the companion.[a] They share a highly eccentric orbit, are viewed orbiting nearly edge-on, and take 34 years to complete an orbit.[3]
The main component (apparent magnitude 4.30) has an spectral class A9IIIp,[4] suggesting it is a late-type giant star and is chemically peculiar. Its physical properties, however, do not support this evolutionary stage and the peculiar class, Mu Ceti is instead in the late main sequence, about to become a subgiant. This star is 67% more massive than the Sun and two times larger. Its effective temperature is 7380 Kelvin,[3] giving it the white hue typical of late A/early F stars.[11] It has been suspected to be a δ Scuti variable,[12] and found to be of constant brightness by some studies,[13][14] but a more recent analysis with the Transiting Exoplanet Survey Satellite confirm this star is a Gamma Doradus variable.[3]
The secondary (apparent magnitude 7.80) is a K0.5V star, indicating it is a dwarf star cooler than the Sun. Mu Ceti B has an effective temperature of 5,250 K and has a mass and radius measuring 80% solar units.[3] Its effective temperature give it an orange hue typical of K-type stars.[11]
Three companions were all discovered during occultations of Mu Ceti by the Moon. An orbit was derived for the brightest with a period of 1,202 days.[15] Later studies have failed to find any evidence of these companions.[16]
Notes
- ^ Inferred from magnitude differences. The equation is: ≈ 25.
![{\displaystyle {\sqrt[{5}]{100}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d26eff2c044a521107db3cf827e04c2b8415691d)
References
- ^ 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.
- ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ a b c d e f g h i j Dyachenko, V. V.; Yakunin, I. A.; Bayazitov, R. M.; Grigoriev, S. A.; Ryabchikova, T. A.; Pakhomov, Yu. V.; Semenko, E. A.; Beskakotov, A. S.; Mitrofanova, A. A.; Maksimov, A. F.; Balega, Yu. Yu. (2024-09-01). "Study of the μ Cet Binary with Speckle Interferometric, Photometric, and Spectroscopic Techniques". Astrophysical Bulletin. 79: 445–463. arXiv:2409.15063. Bibcode:2024AstBu..79..445D. doi:10.1134/S1990341324600698.
- ^ a b Gray, R. O; Corbally, C. J; Garrison, R. F; McFadden, M. T; Robinson, P. E (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. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365. S2CID 119417105.
- ^ a b Reiners, Ansgar (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, arXiv:astro-ph/0509399, Bibcode:2006A&A...446..267R, doi:10.1051/0004-6361:20053911, S2CID 8642707
- ^ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471: 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. ISSN 0035-8711. Mu Ceti's database entry at VizieR.
- ^ Dyachenko, V.; Richichi, A.; Balega, Yu; Beskakotov, A.; Maksimov, A.; Mitrofanova, A.; Rastegaev, D. (2018-08-01). "Lunar occultation observations at the SAO RAS 6-m telescope". Monthly Notices of the Royal Astronomical Society. 478 (4): 5683–5688. Bibcode:2018MNRAS.478.5683D. doi:10.1093/mnras/sty1427. ISSN 0035-8711.
- ^ "Mu Ceti". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日 Archived 2012-02-04 at the Wayback Machine
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 14 September 2024.
- ^ a b "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-18, retrieved 2012-01-16
- ^ Hauck, B (1971). "Short period variable stars. V. Delta Scuti-type stars in the Geneva system". Astronomy and Astrophysics. 11: 79. Bibcode:1971A&A....11...79H.
- ^ Breger, Michel (1969). "Short-Period Variability of b, a, and F Stars. III. A Survey of Delta Scuti Variable Stars". Astrophysical Journal Supplement. 19: 79. Bibcode:1969ApJS...19...79B. doi:10.1086/190199.
- ^ Adelman, S. J (2001). "Research Note Hipparcos photometry: The least variable stars". Astronomy and Astrophysics. 367: 297–298. Bibcode:2001A&A...367..297A. doi:10.1051/0004-6361:20000567.
- ^ Jim Kaler (Dec 21, 2007). "Mu Ceti".
- ^ Hutter, D. J; Zavala, R. T; Tycner, C; Benson, J. A; Hummel, C. A; Sanborn, J; Franz, O. G; Johnston, K. J (2016). "Surveying the Bright Stars by Optical Interferometry. I. A Search for Multiplicity among Stars of Spectral Types F-K". The Astrophysical Journal Supplement Series. 227 (1): 4. arXiv:1609.05254. Bibcode:2016ApJS..227....4H. doi:10.3847/0067-0049/227/1/4. S2CID 118803592.
