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| Brightest Stars on Dec 09, 2012

Menkar is the Whale’s alpha star

Okay, it’s not the most famous star in Cetus. It’s not even the brightest, although it carries the designation Alpha. But Menkar has its own claims to fame.

Menkar ranks as the second-brightest star in the constellation Cetus the Whale, after Diphda (or Deneb Kaitos, aka the Whale’s Tail). All the same, Menkar has been awarded the alpha designation (Alpha Ceti), possibly because Menkar sits closer to the ecliptic, which marks the sun’s yearly circuit in front of the background stars.

And, of course, the most famous star in Cetus is neither of these. It is Mira, a famous variable star.

Still, Menkar has its own claims to fame. For you Star Trek fans, this star played a key role in an original Star Trek episode called “Space Seed” (1967) as well as in the second Star Trek film Star Trek II: The Wrath of Khan (1982). Ceti Alpha V (note flipped Bayer designation) is the planet on which Khan and his crew are exiled in “Space Seed,” and from which they escape in The Wrath of Khan after it is rendered uninhabitable. As of December 6, 2012, there are 853 known extrasolar planets, but apparently none found for the real star Menkar (Alpha Ceti) so far.

A photograph of the constellation Cetus the Whale, via Till Credner and Wikimedia Commons.

When is the best time to see Menkar? As seen from northern temperate and polar latitudes, Menkar shines due south around 9 p.m. local time around the December winter solstice (on or near December 21). Because all the stars, except the sun, return to the same place in the sky about 2 hours earlier with each passing month, that places Menkar highest up and due south around 7 p.m. on January 21.

The V-shaped Hyades star cluster – Face of the Bull in the constellation Taurus – serves as a directional arrow, pointing the way to the star Menkar. Hop two fist-widths from the point of the “V” to locate Menkar’s approximate position in the star-studded heavens. (Hold your fist at arm’s length.)

It’s pretty easy to see Menkar and the Circlet of stars outlining the Head of Cetus the Whale in a dark sky. In the lore of the sky, this fearsome creature almost gobbled up the Princess Andromeda, the daughter of King Cepheus and Queen Cassiopeia. But Perseus the hero rescued the Ethiopian princess in the nick of time.

Sky chart of the constellation Cetus the Seamonster

Image credit: Wikipedia

A small telescope shows Menkar to be a colorful double star. The orange giant star, Menkar, contrasts with its fainter blue-white companion, the star 93 Ceti. These two stars are not physically related but happen to align on the stellar sphere. Menkar resides some 220 light-years away, while 93 Ceti is at least twice that distance away.

Menkar’s ruddy complexion reveals that it’s a cool star in the autumn of its years, and 93 Ceti’s blue-white radiance indicates a hot star in the heyday of youth.

Bottom line: The star Menkar in the constellation Cetus the Whale. History, lore, claims to fame, science.