Distances with <4% precision from type Ia supernovae in young star-forming environments

A place where stars are more predictable Astrophysicists use reference objects of known brightness to determine distances. For example, type Ia supernova (SN Ia) always reach nearly the same peak brightness. This is because they explode when the progenitor white dwarf exceeds its supportable mass threshold. Kelly et al. find that a particular subset of SN Ia—those in environments with high ultraviolet surface brightness and star-formation density—can calibrate distances even more tightly. It seems that only one or two intrinsic parameters may drive the apparent relationship between luminosity, color, and fading with time. Science , this issue p. 1459