COMMENTS ON THE OBJECT :

The globular cluster M13 or Messier 13, very often called the Great Hercules Cluster or simply Hercules, is among the most imposing objects in the Messier catalogue. It was discovered by Edmond Halley in 1714, and added by Charles Messier to his catalogue on June 1, 1764.

With more than 500,000 stars, it is also one of the oldest objects: its age is estimated at 12 or 14 billion years. It appears with a diameter of 20 arc minutes, which is a real diameter of 150 light years. However, it has the particularity of containing many young stars (confirmed by their angular velocity), which is unusual for a cluster of this age: scientists believe that these stars were not born inside the cluster, but rather were captured by it.

M13 was used in 1974 (November 16) as a target to send a message to a potential extraterrestrial civilization. This message was sent from the Arecibo radio telescope, which also participates in the SETI project. It contained information such as numbers, the atomic number of hydrogen, carbon, nitrogen, oxygen and phosphorus, data on DNA, the shape and size of a human, the Earth’s population, and the position of the Earth in the solar system. It will take 25,000 years to complete (the same for the eventual answer).