Whats_up_09-50

Jeff Green | Dec 17, 2009

By Fred Barrett

Probably the easiest to recognize constellation in the night sky after the Big Dipper in Ursa Major, is Orion. It’s a big favourite of mine. Orion the Hunter is accompanied by his faithful canine companions Canis Major and Canis Minor. They hunt by the side of the river Eridanus for celestial prey including Lepus, the rabbit and Taurus, the bull. In Greek mythology, Orion loved Merope who had little if any interest in him. She was one of the seven daughters of Atlas, the god who holds up the sky, and a pretty important job that is indeed. They are better known as the Seven Sisters who form the cluster called the Pleiades. Orion’s love-struck life ended in tragedy when he stepped on Scorpius, the scorpion. The gods, in a rare moment of pity, put him and his dogs up in the sky and placed all the animals he hunted near him. Scorpius was placed in the opposite part of the sky. I guess they figured he might stumble over Scorpius again!

By 10 PM in mid December, Orion is about 45 degrees above the Southeastern horizon. It will continue to rise higher in the south in the evening sky as winter progresses. To its upper right, about 15 degrees, is the Hyades star cluster with the red star Aldebaran, the baleful eye of Taurus the Bull. Carrying on another 10 degrees to the upper right is the Pleiades star cluster (don’t forget that a clenched fist at arm’s length is about 10 degrees).

Referring to the figures, you can see that Orion has a distinct hourglass shape and the three stars at the middle are called the Belt of Orion. The bright star that marks the upper left is Betelgeuse, an M class supergiant near the end of its life. It’s so large that it could contain the entire orbit of the Earth around the sun within its girth! Rigel is the star situated at the bottom right and is a B class supergiant and the 6th brightest star in the sky. It’s 25 times more massive than the sun and is burning its fuel at a tremendous rate. It won’t last much more than a few million years before it explodes as a supernova. Hanging down from his belt are three faint stars, the Sword of Orion. The centre ‘star’ is not really a star at all. It’s the Orion nebula, M42, one of the most studied regions of the Northern night sky. It’s about 1000 light years away and very massive although its material is about a million times less dense than the air we breathe. Nearby is the famous Horsehead Nebula, IC434, which is a region of dust in front of a bright nebula. The whole Orion area is a wealth of binocular objects. A little north of M42 is M43, really an extension of M42. NGC1981, nearby to the right, is an open cluster fairly easy to resolve. To the North of the belt is M78. You may need a telescope for this nebula. A small telescope will also show the four stars that make up the Trapezium at the centre of Orion. Many new stars are forming and evolving in this area of the nebula. Good hunting!

THE MOON – Around 9PM on January 2, a waning (past full and decreasing in brightness) gibbous (outward curving bright portion) Moon is 6 or so degrees to the right of Mars.

The new Moon occurs at 2:11 AM January 15th. About an hour past sunset on the 17th the waxing (increasing in brightness) crescent Moon is a bit down and to the right of Jupiter in the west southwest. On the 24th, a waxing gibbous Moon is close to the Pleiades in the evening sky. Near the end of the month on the 29th, just before sunrise, the almost full Moon is 6 degrees below Mars. The Moon is full at 1:18AM on January 30th and at perigee or closest approach to the Earth. It’s the largest full Moon of 2010.

THE PLANETS – Venus – reaches superior conjunction (it’s behind the Sun) on January 11 and won’t be seen again until February.

EARTH – On January 2nd Earth is at perihelion, its closest approach to the Sun. It will be 147.1 million km. (93.4 million miles) from the Sun; that is about 1.7% closer than average.

MARS – Opposition occurs on the 29th. It makes its closest approach on the 27th when it is 99.3 million km. distant. It won’t make another close approach until 2012.

A modest telescope will allow you make out details on its surface. Try not to miss this opportunity. The almost full Moon’s light will be a problem so you may have to delay a few nights for better viewing. Canals anyone?

JUPITER – It’s very low in the Southwest and difficult to see.

SATURN – Rises about midnight on January 1st in Virgo and about 2 hours earlier by month’s end. The rings reach a tilt of about 4.8 degrees in early January and then start to close up again.

METEORS – The Quadrantid meteor shower occurs on the nights January 2nd to 4th but a just past full Moon will really hinder decent observing.

REMINDERS: Check the Sharbot Lake Pharmacy for a copy of the Royal Astronomical Society’s The Beginner’s Observing Guide by Leo Enright. It’s a great Christmas gift!

Don’t forget that we have an excellent Canadian astronomy magazine, “Sky News”. You can arrange for a subscription by contacting the Royal Astronomical Society of Canada at www.rasc.ca/publications. If you have any comments or suggestion, email me at This email address is being protected from spambots. You need JavaScript enabled to view it. or contact the North Frontenac News.

Clear Skies and Merry Christmas to All.