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KIC 11145123 (sometimes mistakenly called Kepler 1145123 ^[9]), is a white hued star located in the northern constellation Cygnus, the swan. It has an apparent magnitude of 13.12, ^[2] making it readily visible in large telescopes, but not to the naked eye. The object is located relatively far at a distance of approximately 3,910 light years, ^[1] but is rapidly approaching the Solar System with a radial velocity of −136  km/s. ^[5]

KIC 11145123 has a spectral classification of F7V, ^[3] indicating that it is a main sequence F-type star. Atmospheric models suggest it may be hotter and possibly a late A-type star. ^[4] It has 1.4 times the mass of the Sun, in contrast to the 1.7 times that would be expected from a normal late A main sequence star, and 1.57 times its radius. ^[7] It radiates 12 times the luminosity of the Sun from its photosphere at an effective temperature of 7,590  K. ^[8] Unlike most hot stars, KIC 11145123 spins exceptionally slowly with a projected rotational velocity of 1  km/s. ^[8] This corresponds to a period of roughly 100 days. ^[8] Despite appearing as a main sequence star ( Gaia DR3 models it as such), ^[1] it is most likely a blue straggler. ^{[10] [6]}

KIC 11145123 is currently believed be the roundest natural object, with the difference between equatorial and polar radii equaling a mere three kilometers. ^[9]