In astronomy, absolute magnitude measures a celestial object's intrinsic brightness. To derive absolute magnitude from the observed apparent magnitude of a celestial object its value is corrected from distance to its observer. The absolute magnitude then equals the apparent magnitude an object would have if it were at a standard luminosity distance away from the observer, in the absence of astronomical extinction. It allows the true brightnesses of objects to be compared without regard to distance. Bolometric magnitude is luminosity expressed in magnitude units; it takes into account energy radiated at all wavelengths, whether observed or not.The absolute magnitude uses the same convention as the visual magnitude, with a factor of 100(0.2) ( 2.512) difference in brightness between steps in magnitude. The Milky Way, for example, has an absolute magnitude of about 20.5. So a quasar at an absolute magnitude of 25.5 is 100 times brighter than our galaxy. If this particular quasar andour galaxy could be seen side by side at the same distance, the quasar would be 5 magnitudes brighter than our galaxy.