Absolute magnitude from an absolute magnitude in a specific filter band to absolute bolometric magnitude, a bolometric correction is applied. For Solar System bodies that shine in reflected light, a different definition of absolute magnitude (H) is used, based on a standard reference distance of one astronomical unit. In stellar and galactic astronomy, the standard distance is 10 parsecs (about 32.616 light-years, 308.57 petameters or 308.57 trillion kilometres). A star at 10 parsecs has a parallax of 0.1″ (100 milliarcseconds). Galaxies (and other extended objects) are much larger than 10 parsecs, their light is radiated over an extended patch of sky, and
26 Andromedae 26 Andromedae 26 Andromedae, abbreviated 26 And, is an astrometric binary star system in the constellation Andromeda. "26 Andromedae" is the Flamsteed designation. It has a combined apparent visual magnitude of 6.10, which is near the lower limit of visibility to the naked eye. The distance to this system can be estimated from its annual parallax shift of , which yields a range of 610 light years. At that distance, the visual magnitude of the stars is diminished from an extinction of 0.04 due to interstellar dust. The system is moving further from the Earth with a heliocentric radial velocity