Photo by Robert Gendler (2006).
The M13 globular cluster is located in the constellation of Hercules and is one of the great classics of the sky that almost always makes the telescope.
Currently (October) the constellation of Hercules is visible in the early part of the night, at convenient times, in the southwestern sky, so if you have a pair of binoculars or a telescope, you have to spend a few minutes. The components of the stars begin to be solved with a 114 mm telescope. I have a 250 mm primary mirror telescope, and I guarantee you that it is a show.
If you are lucky enough to live under a dark sky, away from the light pollution of cities, you may even be able to see it with the naked eye as it has an apparent magnitude of +5.8.
This globular cluster has an estimated age of about 13 billion years, is 165 light years wide and is 22,200 light years away from Earth.
The first observations were made by Edmond Halley in 1715, who had mistaken him for a nebula without stars, certainly because of the limits of the instrument used. The first to solve its stellar components was William Herschel, the astronomer who discovered Uranus.
The M13 cluster is made up of thousands of stars, among which the variable star V11, a red giant, stands out. The stellar density is so high that sometimes some stars collide forming new stars, a phenomenon of great interest to astronomers.
A curiosity: in 1974 it was chosen as the destination for one of the first attempts to communicate with potential extra-terrestrial civilizations. In that year, towards M13, a brief presentation message was sent from the Arecibo radio telescope, containing information on the Earth, on DNA and on the human species.