HD 145457

HD 145457 is a star located in the northern constellation of Corona Borealis (The Northern Crown) at a distance of around 442 light-years from the Sun,^[2] as determined through parallax measurements. It has been formally named Kamuy by the IAU,^[9] after a spiritual or divine being in Ainu mythology. With an apparent magnitude of 6.57,^[10] it is barely visible to the unaided eye on dark nights clear of light pollution. It is drifting closer to the Sun with a radial velocity of −3.2 km/s.^[2]

HD 145457 is an aging giant star with a stellar classification of K0 III^[4] that has cooled and expanded off the main sequence after exhausting its core hydrogen supply. With the assumption that it is a helium-burning object, the properties of HD 145457 can be derived by comparison with evolutionary tracks.^[3] With an age of 5.2 billion years old,^[7] it is around 1.57 times as massive as the Sun^[5] and has swollen to around 10 times its diameter. It is radiating 50 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,738 K.^[6]

It is a lithium-rich giant, unusual since lithium is rapidly destroyed once a star becomes a red giant. One explanation for the excess lithium in these stars has been a recent engulfment of a planet, but it is now thought more likely to be due to nucleosynthesis in the star. It is generally assumed that these lithium-rich giants are members of the red clump, core helium burning stars at the cool end of the horizontal branch.^[11]