Claim: 7 Ceti (450 Light years away (1 = 9.46 trillion kilometres)) has four luminosity variations, one of which was 19.2 days with an Amplitude of .018.
Evidence: Based upon an annual parallax shift of only 7.3 mas, it is located roughly 450 light years away. The light-year is a unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometres (9.46×10 km) or 5.88 trillion miles (5.88×10 mi). Luminosity variation 19.2 0.018 19.6 0.020 27.1 0.018 41.7 0.017