When the shape of the emitting body is not perfectly regular, more heat is emitted from some regions than others. (sciencedaily.com)
According to astronomers working with the Spitzer Space Telescope, a thick belt of dust (that is probably being generated by collisions between Edgeworth - Kuiper - Belt - type, icy objects) lies some 96 ± 5 to 195 ± 10 AUs out from the star, assuming that the emitting bodies are black bodies (Bryden et al, 2009; Tanner et al, 2009, see HD 115617; and Vogt et al, 2009). (members.nova.org)
Emitted radiation is proportional only to the temperature of the emitting body. (wattsupwiththat.com)