William Hyde Wollaston in 1802 and Joseph von Fraunhofer in 1814 described the dark lines within the solar spectrum.
In the early days of telescopic astronomy, the word nebula was used to describe any fuzzy patch of light that did not look like a star.
When William Huggins looked at the Cat's Eye, he found no continuous spectrum like that seen in the Sun, but just a few strong emission lines.
[3][4] The development of the periodic table by Dimitri Mendeleev and the determination of the atomic numbers by Henry Moseley in 1913 left nearly no room for a new element.
[6] Ira Sprague Bowen was working on UV spectroscopy and on the calculation of spectra of the light elements of the periodic table when he became aware of the green lines discovered by Huggins.