Alpha Ceti is the star's Bayer designation. It has the traditional name Menkar, deriving from the Arabic word منخرmanħar "nostril" (of Cetus). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[10] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[11] included a table of the first two batches of names approved by the WGSN; which included Menkar for this star.
This star, along with γ Cet (Kaffaljidhma), δ Cet, λ Cet (also Menkar), μ Cet, ξ1 Cet and ξ2 Cet were Al Kaff al Jidhmah, "the Part of a Hand".[12]
A light curve for Alpha Ceti, plotted from Hipparcos data,[14] folded with the period derived by Koen and Eyer (2002)[15]
Despite having the Bayer designation α Ceti, at visual magnitude 2.54 this star is actually not the brightest star in the constellation Cetus. That honor goes instead to Beta Ceti at magnitude 2.04. Menkar is a red giant with a stellar classification of M1.5 IIIa. It has more than twice the mass of the Sun and, as a giant star has expanded to about 89 times the Sun's radius. The large area of the photosphere means that it is emitting about 1,455 times as much energy as the Sun, even though the effective temperature is only 3,795 K (compared to 5,778 K on the Sun). The relatively low temperature gives Menkar the red hue of an M-type star.[16]
Menkar has evolved from the main sequence after exhausting the hydrogen at its core. It has also exhausted its core helium, becoming an asymptotic giant branch star,[3] and will probably become a highly unstable star like Mira before finally shedding its outer layers and forming a planetary nebula, leaving a relatively large white dwarf remnant.[17] It has been observed to periodically vary in brightness, but only with an amplitude of about one hundredth of a magnitude.[15]
^ abcJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
^Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN978-1-931559-44-7.
