Looking Up column: Cetus the Whale swims below Mars
The drama of the universe unfolds again with the next clear night. Looking east in mid-October, with Mars still shining bright and ruddy, be ready to catch a whale of a constellation.
This is Cetus, the Whale, and Mars is currently positioned right above it. This time of year, you can see the Whale right along the eastern horizon if, of course, you enjoy a good, low view to the east. By 11 p.m., the Whale is well up in the southeast and positioned on the meridian around midnight. At the same time, Mars is now at its highest in the sky.
The “meridian,” by the way, is a term for an imagined line from due south on the horizon, passing overhead in the zenith, and down to the northern horizon. The North Star is always very close if not right on the meridian.
But back to the Whale. A rather large star grouping, like other constellations, they are drawn differently on star maps, connecting the stars in varying ways. The version I prefer is the one pictured by the late H.A. Rey, children’s book author and illustrator who wrote a classic constellation book, “The Stars: A New Way to See Them.”
Rey reconfigured most constellations to better resemble what they are supposed to represent. Sometimes the reconnecting of lines made for awkward depictions or utilized rather dim stars to finish the picture.
Cetus the Whale, however, is quite well done, with the nose of the Whale on the western end (the far right as we above the equator see it), and the tail on the eastern end (far left). It is also right-side-up as we see it, seeming to swim along the sky as it rises and sets.
The “mouth star” in Rey’s depiction is the most conspicuous, Diphda, also called Deneb Kaitos or Beta Ceti. Diphda is the brightest star in Cetus, magnitude 2.0, and is 96 light-years away.
On the far left in the tail (in Rey’s version) is Menkar, or Alpha Ceti, the second brightest star in Cetus at magnitude 2.5. Menkar, which is 220 light-years away, is red-hued.
Many of the naked-eye stars in every constellation are cataloged by Greek letters, alpha to omega. Generally, alpha is the brightest and omega is the faintest, but sometimes the listing is mixed (as is the case with Cetus, where Beta Ceti is the brightest and alpha is the second brightest).
Tau Ceti, one of the stars marking the whale’s body, is remarkable in that it is the nearest sunlike star at a distance of 11.9 light-years. Tau is a yellow star, magnitude 3.5.
Probably the most well-known star in Cetus, however, is Mira, a star we don’t often see at all without a telescope. Mira, in Rey’s version, is located in the tail. It is the first variable star to be discovered and the prototype of its class - Mira variables. The star varies from magnitude 10, needing a 3-inch telescope to easily see, to magnitude 3, easily viewed with eyes alone in a fairly dark sky. The rise from minimum to maximum takes 332 days.
Its variability was discovered in 1596 by German astronomer David Fabricius (1564-1617), who was also a pastor. He and his son Johannes are also credited with the first confirmed observations of sunspots, using an indirect means to safely view the sun, which they developed.
I’m happy to say, Mira is currently near maximum. The star is 420 light-years from us.
Mira is also called the “Wonderful Star,” and it certainly is. Mira is also labeled as Omicron Ceti.
Cetus the Whale, in Greek mythology, was a sea monster that Hercules and Perseus needed to slay. The English translation turned it into a whale.
Interestingly, Cetus is surrounded by other water-related constellations, Eridanus the River to the east; Aquarius the Water Bearer to the west and Pisces the Fish right above, to the north. Mars is currently passing through Pisces, a rather faint but large constellation.
Be sure to the left of Cetus for the glittering, compact star cluster, the Pleiades, a showpiece in the night sky visible to unaided eyes.
See the crescent moon in the western evening sky this week; first quarter is on Oct. 23.
Keep looking up at the sky!
Peter Becker is managing editor at The News Eagle in Hawley, Pennsylvania. Notes are welcome at email@example.com. Please mention in what newspaper or website you read this column.