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 Miles (Santa Catalina) "Forty kilometres in a leaky old boat . . .", a rare mention of a metric unit in American popular music, and a tolerably accurate conversion (26 miles = 41.8 km). 26 Miles (Santa Catalina) "26 Miles (Santa Catalina)" is a popular song by the 1950s and 1960s pop band The Four Preps. It reached number two on the "Billboard" Hot 100 and number six on the "Billboard" R&B chart in 1958. The song sold over a million copies and the group appeared on several television shows, including "The Gisele MacKenzie Show" (March 15, 1958) and "The Ed Sullivan Show".