international societies generally publish their own journal or newsletter, and some hold large multi-day meetings akin to a scientific conference or convention. They may also have sections devoted to particular topics, such as lunar observation or amateur telescope making. Notable amateur astronomers George Alcock, discovered several comets and novae. Thomas Bopp, shared the discovery of Comet Hale-Bopp in 1995 with unemployed PhD physicist Alan Hale. Robert Burnham Jr. (1931–1993), author of the Celestial Handbook. Andrew Ainslie Common (1841–1903), built his own very large reflecting telescopes and demonstrated that photography could record astronomical features invisible to the human eye. Robert E. Cox (1917–1989) who conducted the "Gleanings for ATMs" column in Sky & Telescope magazine for 21 years. John Dobson (1915–2014), whose name is associated with the Dobsonian telescope. Robert Owen Evans (1937-2022) was an amateur astronomer who currently holds the all-time record for visual discoveries of supernovae. Clinton B. Ford (1913–1992), who specialized in the observation of variable stars. John Ellard Gore (1845–1910), who specialized in the observation of variable stars. Edward Halbach (1909–2011), who specialized in the observation of variable stars. Will Hay, the famous comedian and actor, who discovered a white spot on Saturn. Walter Scott Houston (1912–1993) who wrote the "Deep-Sky Wonders" column in Sky & Telescope magazine for almost 50 years. Albert G. Ingalls (1888–1958), editor of Amateur Telescope Making, Vols. 1–3 and "The Amateur Scientist". Peter Jalowiczor (born in 1966) discovered four exoplanets. David H. Levy discovered or co-discovered 22 comets including Comet Shoemaker-Levy 9, the most for any individual. Terry Lovejoy discovered five comets in the 21st century and developed modifications to DSLR cameras for astrophotography. Sir Patrick Moore (1923–2012), presenter of the BBC's long-running The Sky at Night and author of many books on astronomy. Leslie Peltier (1900–1980), a prolific discoverer of comets and well-known observer of variable stars. John M. Pierce (1886–1958) was one of the founders of the Springfield Telescope Makers. Russell W. Porter (1871–1949) founded Stellafane and has been referred to as the "founder". Grote Reber (1911–2002), pioneer of radio astronomy constructing the first purpose built radio telescope and conducted the first sky survey in the radio frequency. Isaac Roberts (1829–1904), early experimenter in astronomical photography. Discoveries with major contributions by amateur astronomers Cygnus A (1939) is a radio galaxy and one of the strongest radio sources on the sky. Dramatic period decrease in T Ursae Minoris using AAVSO observations