Ro Perseus (ρ Per, ρ Persei, Gorgonea Tertia) Is a star in the . Has a historical name from greek Γορ – „the third Gorgon". Included in the asterism Gorgon’s Head (or Medusa’s Head). In ancient times, however, this asterism sometimes stood out as an independent constellation.Ro Perseus is a fairly cool (3,460 K) red bright giant with an average magnitude of + 3.39m and spectral type M4. At a distance of 317 light years, it emits 3,470 times more energy than the Sun, with most of this radiation coming from the infrared region of the spectrum. Temperature and brightness show that the star’s radius is 164 times that of the Sun, while direct measurements of the angular diameter give 157 solar radii.With a mass of three solar and having an age of 440 million years, Ro Perseus increases brightness for the second time in its life. The first increase in brightness was when all the hydrogen in the core burned out and the core became helium. Currently, Ro Perseus is becoming brighter and larger in size, while in its core, carbon and oxygen are synthesized from helium. Ro Perseus is an SRB semi-regular variable star that changes brightness with periods of 50 and 1100 days, from 3.3m to 4.0m, which is enough to be seen with the naked eye. Approaching the last stage of its life, Ro Perseus is losing mass, and in the near future (after several hundred million years) it will shed its outer shell and become a white dwarf.Belongs to the moving group of Zeta Hercules.