| Jul 10, 2014


by Fred Barrett

Humidity, clouds and rain just about sums it up for June. On the few nights that were cloudless, high humidity made for poor transparency. It was like looking through a foggy window with only the brightest stars showing. It was also a month for an amateur astronomer’s favourite sport – mosquito wrestling!

Let’s hope the weather improves because the summer months are rich with the most spectacular binocular and telescope objects to observe. On a dark, clear night there are star clusters and even a galaxy (Andromeda) that can be seen by the eye, and who can forget the vastness of the Milky Way stretching above from horizon to horizon.

Let’s go on a little tour. There is a trio of constellations that make for rewarding binocular observing throughout the summer. They are Hercules, Corona Borealis and Bootes and they stretch straight overhead in a line from east to west. The best way to find them is to use the Summer Triangle as a reference point to orient you in the sky. I have mentioned the Summer Triangle in previous columns but let’s review finding it. Face south and look up. Almost overhead is a bright star called Vega. It’s in the constellation Lyra. Let your eyes slide about 25 degrees (a clenched fist at arm’s length is 10 degrees; your little finger is 1 degree) to the east. You are now in the constellation Cygnus, the Swan, and the star that is almost as bright as Vega is called Deneb. To find the final star, look southeast from Vega about 30 degrees. You have arrived at Aquila, the Eagle, and the star that is as bright as Vega is called Altair. Now that you have the Summer Triangle in your sights, move your eyes west from Vega about 20 degrees. This is the middle of Hercules. It is shaped like a box with stars branching off from its 4 corners. The globular cluster, Messier 13, is about a third of the way down the west side of the box. Messier 92, also a globular, can be found about 8 degrees above the middle of the top (north) side of Hercules. Both of these DSOs (Deep Sky Objects) are easy binocular objects. Moving west 10 degrees and down a bit, there is an oval of stars that form a bowl. This is Corona Borealis and, although there are no DSOs nearby, it is a beautiful constellation to observe and investigate. There is a fascinating star sitting about a third of the way from the east side of the bowl and about 2 degrees above the bottom. It is called R Coronae and it fades and brightens at unpredictable intervals. It is the most prominent star in the bowl even at minimum. Astronomers believe that the star accumulates clouds of ‘soot’ in its atmosphere that masks the light coming from its surface. When the soot disperses, the star brightens up! Now move west another 10 degrees to Bootes. It is shaped somewhat like a violin and the bright star Arcturus is at the bottom where the finger board would be. Arcturus is the brightest star in the northern hemisphere and has a lovely light orange colour. Seamen of ancient times considered this star unlucky! Up to the north west of Bootes you will bump into the end of the handle of the Big Dipper - the asterism that is part of the constellation Ursa Major. About 5 degrees above the end star of the handle (or ‘tail’ of the Great Bear) is the Pinwheel galaxy (Messier 101) and roughly 4 degrees below the end of the tail is the Whirlpool galaxy (Messier 51). A modest telescope is advisable for both of these DSOs.

Earth was at aphelion on July 3rd. I always get a kick out of thinking that the Earth is farthest from the Sun during the hottest time of the year! Of course, it’s the tilt of the Earth that governs our winter/summer seasons.

The full Moon this month is on the 12th. It is often called the Full Buck Moon. This is the month when the antlers of buck deer are developing and growing. We can all use a few extra bucks of the other kind too! It’s also often called the Full Thunder Moon since thunderstorms are more frequent during this month– and we’ve had a few lately for sure. It’s haying season too and another name is the Full Hay Moon.

Mars is about 1 ½ degrees above Spica in the evening. Do you remember how to find Spica? Use the saying “around the arc to Arcturus and speed on to Spica”. Along a great curving arc from the end of the handle of the Big Dipper we go about 25 degrees to find Arcturus. Continuing on about an equal distance, we bump into Spica. On the 22nd the Moon is 1 ½ degrees to the left of Aldebaran at dawn and on the 24th , just before sunrise, the waning crescent Moon is 5 or so degrees to the right of Venus low in the east north east. Jupiter is behind the Sun on this date. Saturn can be found in the south west at dusk and sets about 2 am. The new moon makes an appearance on July 26th.

This is your first heads up for one of the finest meteor showers of the year. The dependable and active Perseids will light the sky on the evening of August 12-13. Mark that date!

Now I offer you a challenge: the first person to send me the proper name of the star ‘Alpha Coronae’ and describe or make a drawing of where it is in its constellation, will receive a handy little planisphere to use to find your way around the night sky! Add anything special that you can tell me about the star. Can you describe a Globular Cluster?


 

“The Beginner’s Observing Guide” by Leo Enright is an invaluable companion for adventures in the sky. It contains star charts and is available at the Sharbot Lake Pharmacy. It can also be ordered from the Royal Astronomical Society of Canada at www.rasc.ca/publications. A subscription to our very own excellent Canadian astronomy magazine “SkyNews”, with its centerfold sky chart, can be arranged at the RASC website as well.

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