Harrison, John (1693-1776), born near Pontefract invented the ships first chronometer (ODNB).
Ramsden, Jesse (1735-1800), born at Salterhebble near Halifax designed eyepiece (ODNB; McConnell 2013).
Sharp(e), Abraham (bap. 1653-1742), born at Little Horton near Bradford friend of Flamsteed, assisted in setting up Royal Observatory in 1678 (ODNB).
Survey of Astronomical History 