What’s Up in the Night Sky – September

Fred Barrett | Sep 01, 2011

I couldn’t have planned things better! I was searching through my sky charts for a good object for you to look for this month and I wanted it to be in the area where I challenged you last month. I thought it would be doubling your pleasure to practice in a familiar area of sky and it would be a great way for you to refine your observing skills. I considered setting you the goal of finding an unusual asterism close to the two constellations that you searched for last month – Sagitta and Delphinus. What confirmed my decision to have you look for this odd asterism is that there is a Comet nearby! Happily, there were plenty of clear nights in August for observing and I hope you were able to have fun and have a successful search for Delphinus and Sagitta, and are pretty comfortable in the area.

You may remember in previous columns that I mentioned asterisms. They can be a part of a constellation or be a group of stars that remind us of everyday objects. For example, the Big Bear constellation (Ursa Major) has a part of it that is the asterism we call the Big Dipper! Your next mission is that odd asterism called “the Coat hanger” because it looks like - surprise! - a coat hanger. Watch out though; it’s an upside down coat hanger! The Coat hanger is slightly above Sagitta (about 2 degrees) and just past its right end (west). Refer to the star chart to find the Coat hanger. It’s just above the number ‘4’.

To review from last month, you can find Sagitta and Delphinus by visualizing a line between Deneb in Cygnus and Altair in Aquila. They are two of the three stars of the summer triangle. Starting at Altair, go about 1/3 of the way along that line towards Deneb. Now you are in the right vicinity to find Sagitta and Delphius. Above the line is Sagitta and below the line is Delphinus.

Now, about that comet, it’s visible through a small telescope close to the globular cluster Messier 71, which is on the left (east) side of Sagitta. Right now, M 71 and the comet look like two fuzzy patches in binoculars. The comet is approaching the Sun and getting brighter. It should be at its brightest in February 2012 and almost naked eye visibility. This comet is visiting the inner solar system for the first time so what it does may be quite unpredictable. Good hunting for the Coat hanger and for the comet! You can follow along with it as it heads towards Hercules during this month. Try to find it now so you can follow it during the month and see how it changes. I’ll give you an update next month. The comet is called Comet Garradd (C/2009 P1) and was discovered two years ago by Gordon Garradd in Australia.

Clear night skies are always very exciting to me. You have billions of objects to look for through eyes or binoculars or telescopes. This month, September, doesn’t have a lot of spectacular happenings going on. There are no earth-shattering meteor storms or close encounters to watch for! But then again, I don’t think the dinosaurs needed the excitement of a meteor storm to make their day, or end their days. Neither do we!

This month’s full Moon is called a “Harvest Moon”. Need I explain? It occurs at 05:27 on the 12th.

On Sept. 3 the Sun rises at 06:23 and sets at 19:35. On October 1, the Sun rises at 06:58 and sets at 18:41. Winter marches closer. I love autumn and consider it to be the best season for astronomy. The temperature is cool and comfortable and there are few bugs. September and October weather usually provide plenty of clear nights.

Get your binoculars out and look for Mars in the vicinity of the Beehive Cluster (M44) at dawn near the end of the month. Also at that time, Saturn will be close to Venus just after sunset. In previous columns, I have mentioned the Zodiacal light. It is a cone-shaped brightness that is a result of reflected light from particles in the plane of our solar system. Watch for it in the East for a couple of weeks after the 26th of September before morning twilight!

The areas I pointed out last month are still worthy of special binocular attention: Look above Sagittarius, the Teapot, in early evening. The magnificent star fields and star clusters are very worthy of attention. Find a star chart for this heavily populated region of the Milky Way. It will make finding the gems in this part of the sky so much easier.

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..