This Week’s Sky at a Glance, January 6 – 13 ~by Curt Nason
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.