Sky at a Glance November 18 – 25

Photo of the constellation Cetus the Whale in the southern November sky, showing the location of the variable star Mira.

This Week’s Sky at a Glance, November 18 – November 25

November is a time for mid-evening whale watching while the large constellation of Cetus the Whale is well placed for viewing in the southern sky. Many of its stars are not particularly bright so it can be elusive, but you can piece it together in a fairly dark sky. The eastern side of the square of Pegasus is a handy arrow that points down toward Diphda, the brightest star in Cetus. Also called Deneb Kaitos, “the tail of the whale,” it anchors a pentagram of stars forming the rear half of Cetus below dim Pisces. A circlet of stars to the upper left, west of Taurus, is the whale’s head.

A famous star in Cetus is Mira (circled in the diagram), perhaps the first star to be recognized as a variable or one that changes its brightness regularly. The name Mira translates as “wonderful.” It is a red giant star that expands and contracts; brightening as it expands. At minimum brightness it cannot be seen with binoculars, but every 11 months it brightens to easy naked eye visibility. The next maximum is expected to be reached in late December. Midway on the western side of the circlet of the whale’s head is a star that anchors an asterism which resembles a question mark. Don’t ask why, just try it. A scope or binoculars could reveal the galaxy M77 approximately midway between Mira and Menkar, the star at the bottom of the circlet.

In mythology Cetus represents the sea monster created by Poseidon to ravage the coastal area of Ethiopia as punishment for Queen Cassiopeia’s bragging. Her daughter Andromeda was chained to a rock at the seashore as a sacrifice to make the monster go away. Perseus was homeward bound on the back of Pegasus after slaying the Gorgon Medusa when he chanced upon Andromeda’s plight. He rescued the princess by using Medusa’s head to turn the monster to stone, winning the day and the hand of Andromeda.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:24 am and sunset will occur at 4:44 pm, giving 9 hours, 20 minutes of daylight (7:27 am and 4:51 pm in Saint John). Next Saturday the Sun will rise at 7:33 am and set at 7:38 pm, giving 9 hours, 5 minutes of daylight (7:36 am and 4:46 pm in Saint John).

The Moon is new this Saturday, passes near Saturn on Monday, and is at first quarter next Saturday. Mercury is at greatest elongation from the Sun on Thursday evening but I recommend using binoculars to locate it a half hour after sunset, and then try to see it without optical aid. Saturn will be a binocular width above it. By the end of the week Jupiter will be almost halfway between Mars and Venus in the morning sky. The famous Leonid meteor shower peaks on Friday. It is famous for the meteor storms it can produce every few decades when Comet Tempel-Tuttle rounds the Sun, but currently the comet is near its farthest from the Sun. Early Saturday morning will be the best time to see maybe half a dozen meteors per hour.

Questions? Contact Curt Nason.

Leave a Reply

Your email address will not be published. Required fields are marked *