​

At peak brightness type la supernovae can outshine galaxies; however, the supernovae appears faint due to  astronomical distances its light must travel to reach Earth. Scientific instruments measure this light and determine the type of supernova occurred. Various factors provide us with evidence for the type of supernova: light intensity can predict relative distance from Earth, and colour spectroscopy can tell us about the temperature, speed of expansion, along with the chemical constitution of the explosion. When performing spectroscopy, the most reliable colours are yellow to red, these colours only show up for relatively low energy explosions (4000 to 6000 Kelvin), with an expansion rate of approximately 8000 km/sec. Moreover, the degree at which the light undergoes red or blue shift can be used to assist scietists in the mapping of the universe.