Astronomical object with a known Magnitude an object would have if placed at a distance of exactly 10 parsecs (= 32.6 light years). A supergiant star might have an absolute magnitude of -8 whereas a dim red dwarf might have an absolute magnitude of +16. The Sun has an absolute magnitude of +4.8 – about Click on Term to Read More. They are extremely important to astronomers since by measuring the apparent magnitude of the object we can determine its distance. The most commonly used standard candles are Cepheid variable stars and RR Lyrae stars. In both cases, the absolute magnitude can be determined from its variability period. Type Ia supernovae are also considered standard candles, but more correctly they are standardizible candles since they do not all have the same peak brightness. However, differences in peak luminosities correlate with how quickly the light curve declines after maximum light via the Type Ia Stellar explosion that expels much or all of the stellar material with great force, driving a blast wave into the surrounding space, and leaving a supernova remnant. Supernovae are classified based on the presence or absence of features in their optical spectra taken near maximum light. They were first categorized Click on Term to Read More luminosity-decline rate relation, and can be made into standard candles by correcting for this effect.