text: This star defines an apparent magnitude of 0 in photometric bands in visual wavelengths.
full_question: This star defines an apparent magnitude of 0 in photometric bands in visual wavelengths. This star is the prototype of stars which emit infrared light as the result of a circumstellar disc of dust. The surface temperature of this star's poles and equator differ by about 2500 Kelvin, this is a result of its large equatorial bulge. Axial (*) precession will cause this star to replace Polaris as the pole star of the Northern Hemisphere in 12000 years. This star's Flamsteed designation is 3 Lyrae, while its Bayer designation is Alpha Lyrae. For 10 points, name this star which along with Altair and Deneb, forms the Summer Triangle
first_sentence: This star defines an apparent magnitude of 0 in photometric bands in visual wavelengths.