Today is the anniversary of the discovery of the first modern supernova, currently named SN1987A, located in the Tarantala Nebula in the Large Magellanic Cloud. It was independently discovered by both Ian Shelton and Oscar Duhalde of the Las Campanas Observatory in Chile on the night of February 23/24, 1987, and within the same 24 hours independently by Albert Jones in New Zealand. Two weeks later, between March 4–12, 1987 it was observed from space by Astron, a large ultraviolet space telescope. The supernova has yet to receive an official name.
While plenty of modern scientific words can be dated accurately, the older a word is (in general) the harder it is to pin down a date. The word supernova however, defies this logic. Late October 1604 (and some sources give the date 6 November 1604) a new and bright object appeared in the sky. German astronomer and mathematician Johannes Kepler (born 27 December 1571-15 November 1630) noticed the ‘new' object and unsure what exactly it was, simply named it stella nova, from the Latin words for new star. It wasn’t until the 1930s that astronomers Walter Baade and Fritz Zwicky started using the term super-nova and by 1938 the hyphen was dropped and the word became supernova. The first reliably recorded supernova was noted by Pliny in AD 185. Notable supernovae (note the plural maintains the Latin form and does not take the -s that English mostly uses) occurred in 1054, noted mainly by Chinese and Arabic astronomers, and the supernova of 1572 noted extensively by Tycho Brahe.
Time-lapse animation of SN1987A from 1994 to 2009, video compilation courtesy Mark Macdonald, via Larsson, J. et al. (2011). “X-ray illumination of the ejecta of supernova 1987A”. Nature 474 (7352): 484–486., used with permission under a Creative Commons 3.0 license.