QuasarIn 1962, a lunar occultation on August 5 enabled Australian radio astronomers to more precisely fix the location of the previously known radio source 3C 273, in Virgo. In 1963 this became the first member of a new class of object eventually to be called quasars or "quasi-stellar radio sources." Maarten Schmidt, using the Hale optical telescope, saw it as a faint star-like object with a visible jet. Its spectrum featured unusual emission lines, which he identified as ordinary hydrogen lines shifted toward longer wavelengths (redshifted) by 16%. If the shift is due to velocity, it is moving away at one-sixth the speed of light and one of the most distant objects visible. Quasars radiate as much energy per second as a hundred or more galaxies. 3C273 is the brightest quasar known. |
