27
Jun
2022
The Hercules globular star cluster is one of the most famous star clusters of the night sky. It is so bright that it can be seen with a good set of binoculars or even the bare eyes, if one knows where and what to look for.
A globular star cluster is like a satellite made up of several hundred thousands stars orbiting the milky way. To this day they are still one of the big mysteries of astronomy. Why and how are they forming?
It seems that these globular star clusters (globular meaning, its geometric shape is a sphere with its density the highest in its center) are made up of mostly old, metal rich stars. It appears that there are no new stars being born in these clusters. So what causes all these old stars to concentrate at this place in space? Theories suggest there might be a black hole in the center, pulling all those stars into its orbit.
Compared to our interstellar neighborhood, the stars in M13 are packed more than a hundred times closer together. They are so close to each other even, that sometimes stars collide and produce newer, more massive stars.
M13 is located around 22000 - 25000 light years from earth and has a diameter of 145 light years.
Arecibo Message
The 1974 Arecibo message, which contained encoded information about the human race, DNA, atomic numbers, Earth’s position and other information, was beamed from the Arecibo Observatory radio telescope towards M13 as an experiment in contacting potential extraterrestrial civilizations in the cluster. The cluster will move through space during the transit time; opinions differ as to whether or not the cluster will be in a position to receive the message by the time that it arrives
(For more information on the Aricebo message: Wikipedia)