Working as an astronomer with his father, he observed Jupiter's satellites and, from a station near Caen (Normandy, France), the transit of Venus of June 3, 1769. On March 23, 1779, from Frampton House, Glamorganshire, he discovered a "nebula" in Coma Berenices, which later became known as M64 (Pigott 1781). This discovery occurred just 12 days before that by Bode and roughly a year before Messier's independent rediscovery of this object. Perhaps because of its late publication, Pigott's original discovery fell more or less forgotten, although the paper is mentioned on a few occasions, e.g., in the British "Dictionary of National Biography" (Clerk 1896), "The Dictionary of Scientific Biography" (Kopal), and McConnell and Brech (1999). It remained unnoticed, at least in the standard treats on deepsky discovery, and his "nebula" was apparently never identified, until Bryn Jones of Wales recovered it in April, 2002.
Edward Pigott discovered the comet of 1783 (D/1783 W1, 1783 Pigott, P/Pigott) from York, England on November 19, 1783; this comet was independently found by Pierre Méchain on November 26 and observed by several astronomers including Charles Messier.
On September 10, 1784 Edward Pigott detected the variability of Eta Aquilae, then known as "Eta Antinoi", and the first known representative of a class of vartiables later called "Delta Cephei stars" or, perhaps somewhat misleadingly, "Cepheids". This discovery occurred at a time when roughly a dozen of variables were known, and only 6 of them were not novae or supernovae. In the following, he worked together with his neighbor and good friend, John Goodricke, in the field of investigating variable stars; Goodricke found the variablity of Beta Lyrae (Sheliak) and Delta Cephei later in the same year, 1784. Goodricke is reported to have died in 1786 from pneumonia he caught when observing Delta Cephei.
In 1795, Pigott discovered two more variables, R Coronae Borealis and R Scuti. His last paper in the Philosophical Transactions appeared in 1805, on the variability of R Scuti. Maedler states that he was among the early observers of the great comet of 1807; this seems to be the last astronomical record about him.
He died at Bath (England) on June 27, 1825.
Edward Pigott, together with his father, Nathaniel Pigott, was honored by the astronomical community by naming an asteroid after him. Asteroid (10220) Pigott was discovered on October 20, 1997 by R.A. Tucker of the Goodricke-Pigott Observatory, and provisionally designated 1997 UG7.