The hero of the spring constellations

We come now to one of the last of the spring constellations, the great hero, Hercules.

Alas, for this is another of the large constellations (fifth largest in the sky) with dim stars, second and third magnitude, making it difficult, but not impossible to find from backyards in town. To find Hercules a trip to a dark sky place is advised.

The legendary story of Hercules is perhaps one of the best known from classical Greek mythology. The story of a man, the son of Zeus and a mortal woman, given 12 seemingly impossible tasks to accomplish, yet finishing all.

Another minus for the constellation is, it is depicted as being upside down with the head to the south (as it rises in the northeast) and the feet to the north. The major portion of the star group is a trapezoid form, known in astronomical circles, as the Keystone.

As with Orion, it is on its side when it rises. Again thanks to the good folks at Daylight Savings Time, it is not visible above the northeastern horizon until after 11 MDT. However, as the season wears on it can be seen earlier in the evening.

Hercules is depicted as a kneeling man holding either a bow and arrows or a club. The brightest star, Ras Algethi (head of the kneeling man in Arabic) is only a second magnitude star. One foot is on the head of Draco, the Dragon (one of the creatures he defeated as part of the 12 tasks) which can be found winding between Ursa Major (the Big Dipper) and Ursa Minor (the Little Dipper).

Look for the Keystone just east (below) Bootes and Corona Borealis. In fact, the outer edges of the cup of Corona Borealis point right to the Keystone of Hercules.

There are two very nice Messier objects in Hercules. M13, the Hercules Cluster, has been called the best globular cluster in the northern hemisphere. It is a very compact ball of more than a million stars estimated to be ten billion years old and is located around 25,000 to 30,000 light years away.

It is seen as a dim, fuzzy ball with just the eyes alone (again, a dark sky place is needed). In binoculars it is a bigger fuzzy ball. It takes a telescope to reveal the glorious magnitude of this wonderful object. M13 can be found on the top side of the keystone as it is rising about halfway between to two component stars.

M92 is the other object. It also is a globular cluster although not as big or as bright as M13. A telescope displays the cluster to its best advantage. It is found about nine degrees (almost the width of your fist held at arms length) to the left (as you are looking at it) of M13, again between two component stars.

There are also numerous double stars to be found and studied in the constellation.

SKY WATCH: Wednesday night, April 18, look in the west for bright Venus visiting the Hyades star cluster. Look for a slender three-day old crescent Moon down to the lower right.

The Hyades, if you will remember, is the v-shaped face of Taurus the Bull. The trio will be spread over 18 degrees of sky.

The Moon will be closer on the 19th and again spread out on the 20th. Don't forget to look for the Pleiades with this grouping.

First quarter Moon on April 24. Look for an Iridium flare on Thursday, April 19, at 9:06 p.m. local time in the east. More times for Iridium flares can be found at www.heavens-above.com

Next time, back with the bears.