An A-Type Main Sequence Star is a type of star that falls within the spectral classification of A. These stars are characterized by their white to blue-white color and have surface temperatures ranging from about 7,500 to 10,000 Kelvin. They are more massive than the Sun and typically have a mass between 1.5 and 2.5 times that of our star. A-Type stars are known for their strong hydrogen absorption lines in their spectra. These stars are in a stable phase of their life cycle, fusing hydrogen into helium in their cores. They are often found in open star clusters and can be quite luminous, with luminosities up to 100 times greater than that of the Sun. Examples of A-Type stars include Sirius A and Altair. Their relatively short lifespans, typically around 1 to 2 billion years, make them important for studying stellar evolution.