He settled in Wimbledon in south London after marrying Winifred James. A keen amateur astronomer with a particular interest in the sun, Lockyer eventually became director of the solar physics observatory in Kensington London.
In the 1860s he became fastinated by Electromagnetic spectroscopy as an analytical tool, for determining the gas composition of heavenly bodies. Lockyer identified a yellow strip in the spectrum of the sun that conventional scientific opinion of the time held as a known element under extraordinary circumstances. To Lockyer it suggested the existence of a previously unknown element in the sun. He named this element Helium after the Greek word Helios meaning sun. Lockyer's discovery was eventually confirmed in the 1890s.
After his retirement in 1911, Lockyer established an observatory near his home in Salcombe Regis, Devonshire, it was known at first as the Hill Observatory, and after his death as the Norman Lockyer Observatory, which is now operated by the University of Exeter.
Lockyer died at his home in Salcombe Regis in 1920.