Stars in Group 1, including the Sun, are in the main sequence stage of their life, characterized by a diagonal line on the Hertzsprung-Russell (HR) Plot where brightness and temperature increase simultaneously.
Stars in Group 1, represented by the blue color on the Hertzsprung-Russell (HR) Plot, share a common characteristic—they fall along a diagonal line. This pattern indicates that these stars, including our Sun, are in the main sequence stage of their life cycle. The main sequence is a phase in stellar evolution where stars undergo stable fusion reactions in their cores, converting hydrogen into helium.
During this stage, the brightness and temperature of the stars are closely related, creating the diagonal alignment on the HR Plot. The Sun, being part of Group 1, is currently in the main sequence, steadily emitting energy through nuclear fusion at its core. The position of stars in Group 1 on the HR Plot provides valuable insights into their current stage of life and the ongoing nuclear processes within their cores.