What’s up in the sky – September 2010

Fred Barrett | Sep 02, 2010

By Fred Barrett

The nights are getting longer and the sun is setting earlier. Thank goodness we don’t have to stay up quite so late to tour the heavens and there are fewer squadrons of bugs orbiting about our heads. With its crisp clear and steady air, fall is my favourite time for observing. Sunset in early September is around 8:20 PM, with sunrise arriving near 5:50 AM. In late September those times change to about 7:45 PM for sunset and 6:15 AM for sunrise.

We’re off to the big ‘W’ this month - Cassiopeia. This constellation looks like a leaning, slightly flattened on one side, letter W within the Milky Way North East of the zenith. It should be dark enough around 9PM to find it. Face east and look straight up. Cygnus, the Northern Cross, one of the constellations we talked about last month, should be in your field of view. Now shift your eyes towards the Northeast and follow the Milky Way down a bit. The ‘W’ should appear quite prominent (some troublemakers insist on calling it an ‘M’. I like ‘W’!) .

Being in the Milky Way, the area is quite rich in objects to view. Referring to the chart, find the open clusters M103 and NGC 663 by the flattened side of the ‘W’. These are both easy binocular objects. Have a look at NGC 457 nearby, a dimmer open cluster and quite remote. It is a tighter grouping of stars and a more difficult challenge. In the neighbourhood and a little farther down towards Perseus, is the Sword Handle. This is a very interesting object. It contains the double cluster NGC 869,884, made up of bright blue young stars. It appears by eye to be a misty patch in the Milky Way. In binoculars, it is spectacular! M52 is off the end of the larger side of the ‘W’ and it will take a little more effort to find this diffuse cluster in a binocular field of view. You can see a small part of Andromeda on the bottom left edge of the star chart. Have a look at the Andromeda Galaxy, M31. It is the nearest large galaxy to us and can be seen quite readily in binoculars and even by eye on very clear nights in dark areas.

The Moon and Planets

Mars, Venus and the star Spica are very close, within a 4.5 degree circle, in the first days of September but very low in the west southwest. You will have to find a clear horizon. The crescent Moon passes near the grouping on the 10th and 11th. You can follow, in a telescope, the crescent of Venus as it grows longer and thinner as the month progresses. Mars and Venus stay close throughout the month. Mars is a little above Venus and shines at 0.3% the brightness of Venus. Yes, that’s the correct number. It makes it very hard to see Mars even with binoculars. Many people have received that hoax e-mail that says Mars will be as big as the Moon at the end of the month. It’s not going to happen!

Jupiter rises early in the evening now and can be seen blazing away in the East soon after sunset. On September 20th Jupiter is at its closest distance from Earth, with opposition occurring the next day. Coincidently, Uranus also shares that distinction on those dates but you will need a telescope and a detailed star chart to find and see Uranus.

The full Moon this month is on September 23rd at 5:17 AM and is called the Harvest Moon. I think most readers knew the name of this full Moon! The Fall or Autumnal Equinox occurs at 11:09 PM on the 22nd. The Sun is in the same plane as the Earth’s equator. Day and night are approximately equal. The term Equinox derives from two Latin words: aequus (equal) and nox (night). Also, at dusk on the 22nd, Jupiter rises just below the almost full Moon.

STARGAZE 2010 at Charleston Lake Provincial Park on August 12 was a huge success. In between Perseid meteors flashing overhead on a crystal clear night, a long line of excited people waited for a view through my telescope. There were nine other amateurs there with their telescopes. Terry Dickinson’s talk was exceptionally interesting and very well received too.

I usually mention SKYNEWS astronomy magazine at the end of this column. Well, this month I have some very welcome news. In the eight annual SKYNEWS national photo contest, two of the four winners are from Sharbot Lake and area! The winner in the “Best Tripod Mounted Unguided Photo” category is Bill McMullen from Sharbot Lake. The winner in the “Best Deep-Sky with Digital SLR OR WEBCAM-TYPE IMAGER” is Plevna cottage owner Gary Colwell. Congratulations to both. Well done!

If you have questions or suggestions, Fred Barrett may be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it.

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, subscriptions for our very own excellent Canadian astronomy magazine, Sky News, are also available from RASC..