| Aug 04, 2011


By Fred Barrett

Last column I said that we were going to visit the huge constellation Ophiuchus this month. I changed my mind and decided to challenge you with finding two of the smallest constellations. They are the constellations Delphinus, the Dolphin and Sagitta, the Arrow. Small but exquisite, these two gems are slightly to the east side of the summer triangle. I mentioned the summer triangle last month. There are spectacular deep space objects to be found in the area around the constellations Cygnus, Lyra and Aquila within which lie the triangle stars Deneb, Vega and Altair.

My ulterior motive for this challenge is to get you to rummage around in the summer triangle again and reinforce your familiarity with its geography! Also, Delphinus and Sagitta are two little beauties that are fairly easy to find and when they pop out of the star field you wonder why you never noticed them before! First a little background on them.

In Greek mythology, Amphitrite, a sea nymph who had been fleeing from Poseidon’s advances, was swayed to accept his attentions by a dolphin, Delphinus, one of Poseidon’s messengers. Grateful, Poseidon placed the image of Delphinus in the sky. Another story tells of the dolphin that saved the life of the Greek poet Arion of Lesbos when he was threatened by the crewmembers of his ship that were after his gold. He was tossed into the sea but was rescued by a dolphin and thus the association with Delphinus.

The simplest tale for Sagitta tells that it represents the arrow which Hercules used to slay the eagle Aquila that fed upon the liver of Prometheus. To find Sagitta and Delphinus visualize a line between Deneb and Altair, 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. Don’t forget that a star chart is an indispensible aid for finding your way!

There is a meteor shower this month on August 13. It is the Perseid shower but unfortunately it occurs on the night of the Full Moon. You will only be able to see the brightest meteors.

This month’s full Moon is called the Sturgeon moon. Native Americans knew that the sturgeon of the Great Lakes and Lake Champlain were more easily caught during this Full Moon. The New Moon occurs just before midnight on the 28th.

Watch for Mars in the east in the morning twilight. Jupiter rises near midnight in the east northeast at the start of August and at about 10pm at the end of the month. Saturn is in the west southwest shortly after the sun sets. Saturn will set about mid-evening.

The Sun rises about 5:50am and sets about 8:22pm at the start of August. At the end of the month sunrise is at 6:15am and sunset occurs at 7:47pm. That’s happy news for stargazers because it means that the nights are getting longer. Unfortunately for sun worshippers, it means that winter is coming. Another harbinger of winter is the Pleides star cluster. It rises just before midnight in late August. Later, as morning approaches, Orion rises in the east and with it Canis Major and Canis Minor. Canis is Latin for dog and their appearance heralds the Dog Days of Summer.

Areas worthy of special binocular attention:

Look above Sagittarius, the Teapot. There are magnificent star fields and star clusters. Look a few degrees east of the summer triangle star Deneb at the tail of Cygnus, the Swan. See if you can find the North American Nebula in your binoculars. It’s shaped just like North America complete with Florida. Get out a star chart of the region and go exploring in this heavily populated region of the Milky Way. 

 

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..

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Support local
independant journalism by becoming a patron of the Frontenac News.