Hercules


Hercules is the fifth-largest constellation in our sky. It's also one of the dimmest. Although it contains 20 stars, not many are visible unless the sky is very clear and dark. Fortunately, that happens here. Since the new moon is April 30, this is the perfect time to look for it, unless it's raining which we really need this year.

Currently Hercules is high in the east and will be visible through the summer. He's the size of three held out hands high and 3 hands wide. If you face east and look up at him, he appears to be laying on his side with his arms on your right and his legs on your left. If you face south and look up at him, he's upside down with his legs up high and his arms down low.

What's most obvious is the 4-star square that makes up his body. It's the Keystone asterism and is a good way to find him. Look for Arcturus and Vega, the two brightest stars in our sky this time of year.  Keystone is to the upper right of the brilliant blue-white Vega. Arcturus is a brilliant yellow-orange star that is quite high in the SE. Keystone is a third of the way between these two stars.

Hercules is also called the Kneeler because his knees are bent. His right arm is held up holding a club.  Draco the Dragon flies above him and the Northern Crown is to the right of him. So, look to the left of the Northern Crown and above the bright star Vega.

Only his head star Rasalgethi stands out, and even that is only half as bright as the Big Dipper stars.  Rasalgethi is an old Arabic word meaning "head of the kneeler". It has the red hue of a supergiant star. Red giants are common for their brightness which varies widely. This one is two stars.

His highlight is M-13 known as the Great Cluster in Hercules. It's considered the best globular cluster in our night sky. When you look from the east, it's in the top line of the Keystone Square about halfway across. It has about 30,000 stars, but since its 25,000 LY away it's hard to see.

It contains some of the oldest and possibly original stars in our galaxy. So, they are more than 11 billion years old. On a clear dark night, it will appear as a fuzzy patch with the naked eye. Obviously, binoculars or a telescope will show you more.

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