SCP 06F6 is an astronomical object discovered in February 2006 by the Hubble Space Telescope in constellation Boötes that brightened and faded over 100 days with an unusual spectrum matching no known phenomenon. Its extreme luminosity, atypical light spectrum, and rapid variability have led astronomers to propose it represents a new class of celestial object, possibly a pair-instability supernova or the result of exotic stellar collisions.