Fred Barrett | Nov 05, 2009


Looking up at the stars to the South around 8PM in early November, you see Pegasus near the zenith, one of the most prominent constellations in the night sky. It’s usually described as the Great Square of Pegasus and it appears as a great square with legs and a head branching off from the square. Refer to the end of this column for links that will help you in your travels in the night sky. Pegasus, the constellation, originates in the stories of Greek mythology and represents a white, winged horse. At first it’s hard to see the star formation as a horse but that’s because the formation is upside down. Flip it over in your imagination and you can visualize a neck and head with 2 legs sticking out from the square.

The square with extra stars is the front end but the back end is missing. It’s thought that that portion was incorporated into the nearby constellation Aries, the Ram. As the mythology goes, Perseus and Medusa were having a hard time getting along and when Perseus severed Medusa’s head and her blood fell into the sea, Pegasus was born. Sea foam gave Pegasus his radiant white coat. He and his friend Bellerophon tried to go to Mount Olympus but this angered Zeus so much that he sent a gadfly to sting Pegasus and cause Bellerophon to fall to Earth. Pegasus found refuge in the home of the gods and remains there to this day.

Figure 1: Star chart for The Great Square of Pegasus.

In figure 1, the area covered by the map is over 1000 square degrees. Pegasus is one of the largest constellations in the sky although it is not one of the brightest, it certainly is unmistakable! To the East of Enif (Epsilon) is Messier 15, almost naked eye visible. It certainly is prominent with binoculars (7X50’s should do it nicely). Roughly a dozen galaxies can be found in and around Pegasus and the barred galaxy NGC 7331 is the most prominent (I’ll assign part of a future column to how sky objects are catalogued). It is much fainter but should be observable in a modest telescope somewhat above Matar, the “knees” of Pegasus.

Meteor Showers - The first shower of the month is the Taurids. They begin around November 4 and peak around November 11. They are called the Taurids because they appear to eminate (or radiate, thus the term ‘radiant’ of a meteor shower) from the constellation Taurus. The source of the shower is debris left over from the passage of Comet Encke. Taurus is rising early in the evening so we don’t have to stay up late to see these meteors. Unfortunately this shower is usually weak and has a low hourly rate. The Zenith Hourly Rate (ZHR) is predicted to be 15.

The second shower is the Leonids. The best time to view these meteors is just before dawn on the 17th and 18th of November. The constellation Leo doesn’t rise completely until after midnight. The debris stream that causes the Leonids is compliments of Comet Temple-Tuttle. A very good show is predicted for this year with a ZHR estimated to be roughly 150 to 500. There is a time predicted for peak numbers of meteors entering the atmosphere and although Asia is predicted to receive that peak, these predictions are very rough and can be off by hours. For those who will be up, notice that Mars is ahead of Leo the Lion, and Saturn follows.

I will set aside a future column to describe meteor showers and define the words used to describe them.

The Planets: Venus - For you early risers, look to the south-east to see Venus rising about 1½ hours before sunrise in early November. As the month progresses, Venus becomes more difficult to see as it rises later and closer to sunrise. Looking to the south-east about a half hour before sunrise on the 15th, a sliver of a crescent Moon passes to the lower right of Venus.

Mars - Mars can be found moving through Cancer during November crossing into Leo as the month changes to December. Early November finds Mars rising in the east-north-east about 11PM but by the end of the month that time moves up to 9:30PM. Its brightness and size increase too. The brightness goes from magnitude +0.4 to -0.1 (smaller the number, the brighter the object) and the disk increases from 7.9” to 9.9”. At that size, surface features can be made out in a medium size telescope. Remember, Mars gets higher as the night hour gets later and it also moves more to the south. A waning, gibbous Moon can be observed a few degrees below and to the right of Mars looking east-north-east on November 8 around 11PM.

Saturn - Although very dim, it is best observed in the east-south-east near dawn. Its rings are opening up again, 3 to 4 degrees, from the edge on view displayed these last few months.

Jupiter - It is lowering into the south now as November passes. At Magnitude -2.4, it is still the brightest non star object in the sky except for the Moon. On November 23 at dusk, the Moon sits a few degrees above Jupiter. For those of you with telescopes, have a look at 7.9 magnitude Neptune as its distance from Jupiter decreases from 6 degrees to 3 degrees as the month closes.

Next month: Geminid meteor shower with no moon and the truth about Blue Moons.

An excellent source of information is provided by our very own Canadian Astronomy Magazine: Sky News. The editor is Terence Dickinson who lives near Kingston. Visit skynews.ca for more information.

 

The Beginner’s Observer’s Guide by Leo Enright is available at the Sharbot Lake Pharmacy or by contacting the Royal Astronomical Society of Canada www.rasc.ca/publications.

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