75 Ceti
75 Ceti is a single star in the equatorial constellation of Cetus with at least one planet. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.36. The star is located 271 light years distant from the Sun, based on parallax, but is drifting closer with a radial velocity of −6 km/s.
In Chinese, 天囷, meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, 75 Ceti itself is known as the Tenth Star of Circular Celestial Granary.
This is an aging giant star with a stellar classification of K1 III, having exhausted the supply of hydrogen at its core and expanded to 10.6 times the Sun's radius, or. It is a red clump giant, which indicates it is on the horizontal branch and is generating energy through helium fusion at the core. The star is 1.4 billion years old with 1.9 times the Sun's mass. It is radiating 56 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,846 K.
The planetary companion was discovered by Doppler measurements at the Okayama Astrophysical Observatory, and announced in 2012. The planet's discoverers consider the planet, designated 75 Ceti b, to be "typical" of gas giants. Note that b takes in much more insolation than does Jupiter and, indeed, Earth.
There may be additional periodic factors in the data, corresponding to m sin i of around
and, at distances of ∼0.9 AU and ∼4 AU, where i is the orbital inclination and m is the planet's actual mass. If these additional companions are confirmed, they are more irradiated than Earth as well.
