S-type star

An S-type star, also known as a Type S star, is a red star with a surface temperature of approximately 2,400 kelvins. These stars are characterized by a high proportion of carbon and other heavier elements on their surface. The superabundant elements found in S-type stars are believed to originate from the slow neutron process, a nuclear reaction that occurs during stellar evolution. This process involves the capture of neutrons by atomic nuclei, leading to the formation of heavier elements. The presence of technetium-99 in these stars provides evidence that these processes are currently active.123