Dennis Walsh (12 June 1933 – 1 June 2005[citation needed]) was anEnglishastronomer. He was an earlyradio astronomer, as well as anoptical astronomer. He was best known for his discovery in 1979 of the first example of agravitational lens,B0957+561, using an optical telescope.[1]
He was born into a poor family inDukinfield, east ofManchester.[1]
He married Pamela Lawton[1] in 1957, with whom he had four sons, named Colin, Timothy, Paul and Brian (the latter three born in the USA). Dr. Walsh taught and also oversaw 16 Ph.D courses for various students, including one who would later go on herself to teach acclaimed British physicist and maker of documentaries,Brian Cox.[citation needed]
In his last years Dr. Walsh suffered fromLewy body disease. He died at home at the age of 71.[citation needed]
He developed an early aptitude formathematics andphysics.[citation needed] He received a scholarship from theUniversity of Manchester, where he received a first class honours degree in Physics[1] at the age of 19.[citation needed] In 1953 he started studying for aPhD fromJodrell Bank, supervised byRobert Hanbury Brown, where he constructed a 92MHz receiver for theTransit Telescope. Working withCyril Hazard, he used the receiver to carry out a radio source survey, detecting 134 sources. The survey was limited bysource confusion, an issue that Dennis and Cyril identified for the first time.[1]
He completed his PhD in 1957. He worked forFerranti for a short time, before moving to theUniversity of Michigan[1] in 1959[citation needed] to teach and to research low-frequency radio emission in theionosphere, for which he usedsounding rockets. He returned to theUniversity of Manchester in 1967 in order to work on atmospheric research using theAriel 3 satellite, and to lead the "survey group", while supervising PhD students.[1]
He used a wide variety ofoptical telescopes, having learnt about optical observing using theIsaac Newton Telescope, before being one of the first western astronomers to use the SovietBTA-6 telescope.[1]
TheJodrell Bank 966MHz survey was led by the survey group at Jodrell Bank. Walsh's spectroscopic follow-up ofquasars in this survey led to the 1979 discovery of the first example of agravitational lens,B0957+561, using an optical telescope at theKitt Peak National Observatory.[1]
Dr. Walsh was a long serving council member of theRoyal Astronomical Society, where he held the post of Treasurer from 1988 for eight years. He organised the finances for theInternational Astronomical Union's General Assembly meeting in Manchester in August 2000.[1]