English scientist who studied the spectra of solar prominences and sunspots. Through his pioneering work in spectroscopy, he discovered the existence of helium.
Lockyer was born in Rugby, the Midlands, and began as an amateur astronomer. In 1869 he founded the scientific journal Nature, which he was to edit for 50 years. He was director of the Solar Physics Observatory in South Kensington, London, 1890-1911.
In 1869 Lockyer attached a spectroscope to a 15-cm/6-in telescope and used it to observe solar prominences at times other than during a total solar eclipse. Although Lockyer had been the first to think of it, the same idea had occurred to French astronomer Pierre Janssen, then working in India, and they simultaneously notified the French Academy of Sciences of the same result. Later they worked together, Janssen providing the observations of the Sun's spectrum that led to the discovery of helium.
Lockyer also developed the theory that Stonehenge is oriented towards the direction in which the Sun rises at the time of the summer solstice. From the gradual change in position of the solstitial sunrise, he calculated that the monument must date from 1840 BC, plus or minus 200 years - later confirmed by radiocarbon dating.