With the Moon rising later and later, we have more of a window of “darkness” in the evening to enjoy the stars. This is not to belittle the Moon; we are thankful for our faithful friend, our satellite which has meant so much to us and keeps us out of trouble from many incoming meteoroids (too bad for the Moon, though).
In fact the soft lunar light bathing the landscape, quite natural, is far more tolerable than society’s thoughtless habit of needlessly lighting up the sky rather than keeping night lighting aimed to the ground where it is meant. When the Moon is full or nearly so, can could easily read newspaper headlines outside. Brighter stars and planets still shine through, sparkling the dull blue moonlit firmament above us.
Full Moon was on November 23; last quarter is on the 29th.
If you’ve never seen a whale, take a look before the Moon rises. On late November/early December evenings, look south for the large, dim constellation, Cetus the Whale. Let your eyes adapt to the darkness for a few minutes, to see the fainter stars. Cetus does have a moderately bright star, magnitude 2, which is named Diphda and marks the whale’s mouth. In the tail there is a remarkable star that comes and goes. Most of the year you won’t find it, and then for a while, it is bright enough to be easily seen without even binoculars.
This star is called Mira, The Wonderful. Mira is a long-period red giant variable star. Located about 350 light years from Earth (that’s how long it takes for its light to reach here), the star’s variability was realized in 1596. In a period of 331 days, it rises from 10th magnitude (requiring about a three-inch wide telescope to see) to 2nd or 3rd magnitude, easily seen with unaided eyes. A telescope will show its distinct red color.
Sky at Night Magazine reports that from late November into December, Mira should be visible to the naked eye. Maximum light is expected in mid-December 2018. To give you an idea about magnitudes, the stars of the Big Dipper range from 3rd to 2nd magnitude.
A faint tail of gas and dust trails behind Mira as it speeds through space. It was found in ultraviolet light pictures taken by a satellite camera. The tail is nearly 13 light years long.
Another star within the outline of Cetus, known as Tau Ceti, is one of the Sun’s nearest neighbors, only 11.8 light years away.
Telescope users will want to look just south of Cetus for a bright galaxy, NGC 253, long and narrow in shape.
Menkar, a 3rd magnitude star in the tail, is yellow in color and has a fainter blue star right next to it, a nice sight at low power in a small telescope. The Greeks connected Cetus the Whale in their mythology with the story of constellations Perseus and Andromeda. In the 17th Century, Cetus was linked to the Biblical story of Jonah.
Cetus is sometimes pictured not as a whale, but as a sea monster.
Keep looking up!
— Peter Becker is Managing Editor at The News Eagle in Hawley, PA. Notes are welcome at firstname.lastname@example.org. Please mention in what newspaper or web site you read this column.