As we near mid-June, stargazers in southwest Iowa have the opportunity to view a unique constellation overhead that has several identifying features but the one that intrigues me the most is known as the “Flower Pot.”
Officially, the constellation is named Hercules, the Kneeler, and is slightly to the east of overhead at 10 p.m.
If you have a problem locating Hercules, try to first find the tiny circlet of stars called Corona Borealis. Facing north, Hercules will be just to its left.
Once you have found the constellation, the formation that will most likely catch your attention are the four stars that are arranged in the shape of a keystone, or Flower Pot. The pot appears to be lying on its side with the top portion pointing to the north.
Looking at the shape, the star in the upper left of the “pot” is called Pi Herculeum while the one in the upper right is Eta, the one in the lower right Zeta and the lower left, Epsilon.
Directly between Eta and Zeta is a tremendous cluster of stars identified by its Messier designation, M-13. In very dark skies, the Hercules Cluster is visible to the naked eye as a fuzzy star but you’ll need 10 power binoculars or a telescope to resolve many of the stars making up the cluster. Don’t expect to resolve them all; it is extremely difficult unless you have a very large telescope.
When I look at the cluster with my binoculars, which are 10 power, I can see the dense center of the cluster very well. Looking at it with my telescope I can easily resolve many stars lying on the outer edges.
As you view it, remember it is made up of over 100,000 individual stars and is truly amazing. Size-wise, each of the stars is a giant when compared to our parent Sun and when you are looking at the cluster stop for a moment and consider that at the very moment the light is striking your eyes it had started the journey 23,000 years ago.
There are over a thousand globular clusters such as M-13, so many spread out around the center of our galaxy they are sometimes collectively referred to as our galactic halo.
How did these globular clusters come about? Great question!
Most astronomers believe that the stars formed in especially large numbers — large enough so that their mutual gravitational attraction was sufficient to keep them together for the billions of years that the galaxy has endured.
Most stars are moving to some degree, a motion known as “proper motion”. The region of the sky in which Hercules is situated is considered by many astronomers as remarkable in the fact that hardly any two stars are moving in the same direction or at the same “proper motion”.
Any stargazing activities may have to take a back seat this week since June’s full moon occurs next Monday and the brilliant moonlight at the present time will do a great job on washing out many celestial vistas.
Not to worry, however, Hercules will continue its journey westward and will be overhead or nearly so for the next couple of weeks.
On another subject, next Monday evening, June 17, about 45 minutes after sunset and assuming to skies are clear observers using binoculars will be able to view two of our solar system’s planets, Mercury and Mars appearing to almost touch each other.
Making sure the sun has completely set, look slightly toward the west-northwest to view these two objects. Mars will be to the left side of the pair.