The question of winter observing always comes up. The fear in people’s eyes when they hear many astronomers including myself, have been out as low as -25 degrees Celsius is priceless. Astronomy is not just a three season hobby! Yes, Canadian winters can be brutal at times but there are many advantages to admiring the skies this time of year.
Winter nights are long and haze-free. You can also begin after dinner as opposed to a 10:30 p.m. start in the middle of summer. The most obvious reason is seeing the 13 of the brightest stars in the entire sky. From the dark skies of Northeastern Ontario, the fainter external portion of the Milky Way Galaxy can be seen running through Taurus and down the left side of Orion.
Orion the Hunter is now perched on the eastern horizon by 7 p.m. local time. To the upper right is his foe in battle, Taurus the Bull designated by the V shape horns which is actually the Hyades cluster residing 150 light years away. The bright star representing the “eye” of the bull is named Aldebaran—a foreground star at the distance of 66 light years but not physically part of the cluster.
All stars are born from vast interstellar clouds of gas and dust called a nebula. Numerous examples are found in galaxies including our own Milky Way. The Great Orion Nebula (catalogued as M42) is the closest stellar nursery to us and is located in his sword. It is 1,500 light years away and about 24 light years wide. In an estimated 100,000 years, hundreds of stars will become suns, forming a lovely cluster. Stars slowly evolve through their stages of life lasting millions or billions of years. As stars like our Sun run out of fuel, they expand to red giant status. Betelgeuse—the top left star of Orion is 600 light years away and has the distinctive orangey-red colour to it. If we placed in the middle of our solar system, it would expand to the orbit of Jupiter. By comparison, if Betelgeuse was a meter wide, our Sun would scale down to less than a millimetre. Keep in mind 109 Earths fit across the Sun’s equator.
Speaking of a young cluster, move further to the upper right to the Pleiades—the mythological heart of the bull. Estimated to be about 100 million years ago, the Pleiades are around 450 light years away. A true test to sky conditions is to spot all seven suns with just your eye. Try imaging Orion and Taurus with a wide angle lens on a DSLR camera mounted on a tripod. You will have to keep the camera shutter open for about 20 seconds so point and shoot cameras are not ideal.
Binoculars will be required to spot all three wonderful open clusters in the constellation Auriga—the Charioteer. The brightest star Capella is 43 light years away and 170 times the luminosity of our Sun. Capella is one of the three brightest stars seen in northern skies. The three before mentioned clusters are located at the bottom portion of Auriga and are catalogued as M36, M37 and M38. They are in the 4,000 light year range in distance and each measure about two-thirds the width of the full moon.
As a side note, “M” stands for the great 18th century comet hunter Charles Messier with 13 discoveries to his name. While hunting for comets, he came across bright clusters, nebulas and galaxies. He decided to plot these on a star chart so if he came across them again, could immediately rule out a comet. There are 110 Messier objects to which most can be seen in simple binoculars and is an excellent list for the beginner.
The planet Venus is moving higher in the western sky and is so bright. From dark sites it casts a shadow of your hand on a sheet of paper. A telescope shows the planet in phase structure, much like a first quarter moon. Through January follow Venus as it climbs the western skies towards the planet Mars. On Jan 1, the red planet will be more than 250 million kilometres from Earth compared to its 75 million kilometre close approach at the end of May this year. The planet Jupiter is a bit dimmer than Venus but rises in the east around 1:30 a.m. local time.
The only meteor shower slated for January is the Quadrantids that will peak on the morning of 4th. The entire shower lasts from a few days so window of opportunity to see anywhere from 50 to 100 meteors per hour is not long lived.
Until next time, clear skies everyone.
Gary Boyle is past President of the Ottawa Centre of the Royal Astronomical Society of Canada and has been interviewed numerous times on Canadian radio stations. Gary is an astronomy educator and lecturer with a never ending passion for the night sky.
Look for the International Space Station passing near or over:
Chapleau – Cochrane – Elliot Lake – French River – Iroquois Falls
Kapuskasing – Killarney – Kirkland Lake – Manitoulin Island – Mattawa – Moosonee
North Bay – Sudbury – Temagami – Temiskaming Shores – Timmins – Wolf Lake