M67 - NGC 2682

Messier 67 (NGC 2682), sometimes called the King Cobra Cluster, is one of the oldest known open clusters, located approximately 2,700 light-years from Earth in the constellation Cancer. It was discovered by Johann Gottfried Koehler around 1779 and cataloged by Charles Messier in 1780. With an estimated age of about 3.7 to 4.6 billion years, M67 is nearly the same age as our Sun, making it an extraordinarily important laboratory for understanding stellar evolution and the properties of solar-type stars in a cluster environment. Most open clusters disperse within a few hundred million years due to gravitational perturbations, but M67 has survived because it orbits relatively far from the galactic plane, reducing the frequency of disruptive encounters with giant molecular clouds. The cluster contains approximately 500 stars, including many that closely resemble the Sun in mass, temperature, and chemical composition. This has made M67 a key target for exoplanet searches, stellar activity studies, and calibrations of stellar evolution models. Several planets have been discovered orbiting stars in M67. The cluster also contains a number of blue straggler stars and white dwarfs, providing insights into the end stages of stellar life. Visually, M67 is a rewarding target even for small telescopes. At a visual magnitude of about 6.1, it appears as a large, rich swarm of stars spread across about 30 arcminutes, nearly the size of the full Moon. Binoculars show a fuzzy patch of light, while a 4-inch telescope resolves dozens of individual stars in an attractive, scattered pattern. The cluster is located about 2 degrees west of Acubens (Alpha Cancri).

M67 contains roughly 500 stars within a span of about 30 arcminutes, lies 2,700 light-years away, and is approximately 4 billion years old.