25_Cancri
25 Cancri
Star in the constellation Cancer
25 Cancri is a common proper motion[4] star system in the zodiac constellation of Cancer, located around 148 light-years away from the Sun. It has the Bayer designation d2 Cancri (d2 Cnc); 25 Cancri (25 Cnc) is the Flamsteed designation. It is near the lower limit of visibility to the naked eye in good viewing conditions, appearing as a dim, yellow-white-hued star with a combined apparent visual magnitude of 6.11.[2] The pair have a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.245″ per year.[9] It is moving further from the Earth with a heliocentric radial velocity of +38 km/s.[1]
Based upon a stellar classification of F6 V,[3] the brighter component is an F-type main-sequence star that is generating energy through hydrogen fusion at its core. Cowley (1976) listed a class of F5 IIIm?,[10] which suggests it may be an Am star. However, this has not been confirmed.[6] It is about 2.5[5] billion years old with 1.51[4] times the mass of the Sun. The star is radiating 6.6[2] times the Sun's luminosity from its photosphere at an effective temperature of 6,487 K.[5]
The companion is 4.19 magnitudes fainter than the primary, and lies at an angular separation of 16.798″ along a position angle of 310°, as of 2013.[8] If the pair are gravitationally bound, then they orbit each other with a period of around 4.05 million years.[4]