SALT2

SALT2 (Spectral Adaptive Light curve Template 2) is a method used by astronomers to analyze light from Type Ia supernovae—stellar explosions that serve as cosmic distance markers. It creates a model of a supernova's brightness and color over time, accounting for variations among different supernovae. By fitting this model to observed data, scientists can accurately determine how far away the supernova is, aiding measurements of the universe's expansion. SALT2 improves the precision of these distance estimates, making it a vital tool in understanding cosmic acceleration and dark energy.