Evans, John Silas, Canon (1864-1953), amateur astronomer and author, studied in Lampeter, later in life retired to Aberystwyth.
Evans; Thomas Luther, Captain (1852-1929), amateur astronomer, born Aberaeron.
Griffith, John, Rev. (1860-?), amateur astronomer and early investigator into megalithic astronomy, born Ponterwyd.
Jenkins, Griffith Parry (1860-1940), amateur observer, popular lecturer, originated from Llancynfelin: later emigrated to Canada.
Jones, Evan Lewis (1876-?), popular lecturer, born Aberaeron.
Jones, Rhishard Llewelyn (1865-1932), Deputy Director of Kodaikanal and Madras Observatories, India, born in Uchaf-Talybont.
Owen, Gwilym [Prof.] (1880-1940), professor of physics at Aberystwyth.
Owen, John R. (?-c.1977), of Llanrhystud, amateur astronomer, observer, popular lecturer, took possession of Pontllyfni meteorite.