Chi Pegasi

This relatively faint star, as seen from Earth, shines at magnitude +4.80, making it dimly visible to the naked eye under most conditions. It lies along the eastern side of the Square of Pegasus, northward of the much brighter star Algenib that forms the Square's southeastern corner, and very close to the border between Pegasus and its neighbour Pisces to the east. Chi Pegasi lies approximately 347 light years from the Solar System.

The star itself is ancient, with estimated age of some eight billion years making it nearly twice as old as the Sun. Over that immense period of time, it has consumed its hydrogen fuel and moved away from the main sequence, expanding to form a red giant. Though Chi Pegasi is only marginally more massive than the Sun, its expansion has left it with more than fifty times the Sun's diameter, forming a highly luminous object nearly half an Astronomical Unit across. There are indications that this star is slightly variable, showing small changes in its luminosity over a regular period of some six days.