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This Week’s Sky at a Glance, January 20 – January 27

There is one river seen from New Brunswick that is completely ice-free all winter, but we can only see it at night. Eridanus the River, the fifth largest constellation in area of sky, has its head just off the foot of Orion near Rigel. Even when it is at its highest in our sky, the river’s meandering path takes it more than ten degrees below the horizon to where it terminates at Achernar, the ninth brightest star.

In mythology the river is associated with Phaethon, a mortal son of Apollo. Apollo drove the Sun, a golden chariot powered by mighty steeds, across the sky by day. Phaethon was allowed to drive it one day but he couldn’t control the steeds. They ran amok, scorching the sky (the Milky Way) and the Earth (Sahara), until Zeus blasted Phaethon with a thunderbolt and he fell to his death in the river. The twisty constellation was also considered to be the path of souls.

Although we can’t see Achernar without travelling to Florida, there is a notable star in Eridanus that we can see from outside a city. Omicron-2 Eridani, also called 40 Eridani or Keid (circled on the map), has a famous fictional and fascinating planet: Vulcan, the home of Spock. Did you know that there was once believed to be a planet closer to the Sun than Mercury? It was named Vulcan after the Roman god of fire, metalworking and the forge. Anomalies in Mercury’s orbit were thought to be due to an interior planet, and some astronomers even claimed to have seen it crossing the Sun. This was about 150 years ago, after Neptune was predicted and discovered based on anomalies in the orbit of Uranus. Coincidentally, regarding the god Vulcan, the constellation Fornax the Furnace barely crests our horizon near Eridanus.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:54 am and sunset will occur at 5:07 pm, giving 9 hours, 13 minutes of daylight (7:56 am and 5:14 pm in Saint John). Next Saturday the Sun will rise at 7:47 am and set at 5:17 pm, giving 9 hours, 30 minutes of daylight (7:50 am and 5:24 pm in Saint John).

The Moon is at first quarter on Wednesday, giving great views in a telescope of its craters and mountains all week. Jupiter and Mars are well-placed in the south for morning observing, and Saturn rises almost two hours before sunrise. Mercury is heading sunward and is difficult to pick out with binoculars.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, January 13 – January 20

With Orion’s hourglass figure now above the horizon after sunset, the giant hunter waits an hour or so for his two dogs to get up before he starts hunting. The first to greet the night is Canis Minor the Little Dog, a small constellation highlighted by Procyon, the eighth brightest star. To identify this star, Orion’s head and shoulders form an arrowhead, with orange Betelgeuse at the apex, which points toward Procyon. Like Sirius in Canis Major, this star is bright because it is in our celestial backyard, about 11 light years away.

The name Procyon means “before the dog,” indicating it is a harbinger of Sirius the Dog Star which rises about 40 minutes later. Ancient Egyptian farmers watched for the first visible rising of Sirius before sunrise, as experience had taught them the Nile would soon flood its banks with fertile soil when this occurred. In mythology the two dogs are sometimes depicted as Laelaps (Canis Major), an extremely fast dog and an equally fast fox. The dog was sent to hunt the fox but, after a long chase with no apparent end, Zeus turned them both to stone and placed them in the sky.

I like to look at the dogs and their westerly neighbours, Orion the Hunter and Lepus the Hare, in a more modern sense. The mighty demigod Orion becomes everyone’s favourite hunter, Elmer Fudd, with that wascawwy wabbit bugging him below his feet. Although not related directly to Bugs Bunny cartoons, the big and little dogs become Spike and Chester. Just as Chester would bounce around in front of his hero, the bulldog Spike, Canis Minor bounces up before Canis Major.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:58 am and sunset will occur at 4:57 pm, giving 8 hours, 59 minutes of daylight (8:00 am and 5:05 pm in Saint John). Next Saturday the Sun will rise at 7:54 am and set at 5:07 pm, giving 9 hours, 13 minutes of daylight (7:56 am and 5:14 pm in Saint John).

The Moon is new on Tuesday and, with binoculars and some weather luck, the old crescent might be seen near Mercury and Saturn on the morning before. Those two planets are closest together this weekend. Also on Monday morning, Mars is a binocular-width to the lower left of Jupiter. Having passed Jupiter last weekend, Mars sets its sights on a rendezvous with Saturn in early April.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, January 6 – January 13

Around midnight in the first week of January the brightest star in the night sky is due south, at its highest above the horizon. Astronomers would say it is transiting the meridian when it crosses the north-south line. Many 19th century observatories, including the one now called the William Brydone Jack Observatory at UNB Fredericton, would collaborate in timing the transits of stars to determine the longitude of the observatory.

Sirius is part of the constellation Canis Major the Great Dog, one of Orion’s hunting companions. If you are unsure which star is Sirius just follow Orion’s belt down to the left. The star is about twice the size of the Sun and 25 times more luminous, but that is not why it is the brightest. It is only 8.6 light years away, a mere 82 trillion kilometres, and the nearest naked eye star for us in New Brunswick. The name means “scorcher” or “scintillating one” and it often twinkles wildly and colourfully, especially when it is lower in the sky. On more than one occasion I have been contacted by someone who has seen Sirius flashing colours and wondered if it was a UFO. I like to observe it with binoculars or a telescope just to enjoy the light show.

Canis Major is one of those constellations that actually resembles what it represents. Look for the star cluster M41 below the body of the dog, about a binocular field from Sirius. You might pick out a few fainter clusters near the dog’s tail. The big dog appears to be chasing Lepus the Hare, which sits below Orion.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 8:01 am and sunset will occur at 4:49 pm, giving 8 hours, 48 minutes of daylight (8:03 am and 4:57 pm in Saint John). Next Saturday the Sun will rise at 7:58 am and set at 4:57 pm, giving 8 hours, 59 minutes of daylight (8:00 am and 5:05 pm in Saint John).

The Moon is at third quarter on Monday and makes a scenic grouping with Jupiter and Mars on Thursday morning. Mars is less than a Moon-width below Jupiter on Sunday morning. Mercury is just to the right of Saturn on Friday, January 12 and below it the next morning. Venus passes behind the Sun on Tuesday and it will be seen low in the west after sunset in March.

The Saint John Astronomy Club meets on Saturday, January 6 at 7 pm in the Rockwood Park Interpretation Centre. The William Brydone Jack Astronomy Club meets on Tuesday, January 9 at 7 pm in the UNB Fredericton Forestry / Earth Sciences Building. All are welcome.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.