Final answer:
Type Ia supernovae serve as standard candles due to their consistent maximum luminosities and predictable light curves, making them invaluable for measuring distances to distant galaxies and studying the expansion of the universe.
Step-by-step explanation:
Type Ia supernovae are considered standard candles for measurement because of their consistent luminosity across occurrences. These cosmic events are the result of a white dwarf in a binary system accumulating enough material to exceed the Chandrasekhar limit, leading to a spectacular explosion. At peak intensity, a Type Ia supernova can outshine its host galaxy, and its light output increases then decreases in a predictable manner, making it perfect for measuring large cosmic distances.
The discovery that they can be used as standard candles has allowed astronomers to measure the rate of expansion of the universe, which has been found to be accelerating over time. Large telescopes help in obtaining spectra to measure redshifts of the host galaxies and further use these measurements in researching the evolution of the universe. Given their visibility in very distant galaxies and their consistent energy outputs, Type Ia supernovae are the most accurate standard bulbs currently available for extragalactic distance measurements.