Editing Timeline of solar astronomy (section)

==19th century==
* 1802&nbsp;— [[William Hyde Wollaston]] observes dark lines in the solar [[electromagnetic spectrum|spectrum]]
* 1814&nbsp;— [[Joseph von Fraunhofer|Joseph Fraunhofer]] systematically studies the dark lines in the solar spectrum
* 1834&nbsp;— [[Hermann von Helmholtz|Hermann Helmholtz]] proposes [[gravitation]]al contraction as the energy source for the Sun
* 1843&nbsp;— [[Heinrich Schwabe]] announces his discovery of the sunspot [[Solar cycle|cycle]] and estimates its period to be about a [[decade]]
* 1852&nbsp;— [[Edward Sabine]] shows that sunspot number is correlated with [[geomagnetic field]] variations
* 1859&nbsp;— [[Richard Christopher Carrington|Richard Carrington]] discovers [[solar flare]]s
* 1860&nbsp;— [[Gustav Kirchhoff]] and [[Robert Bunsen]] discover that each [[chemical element]] has its own distinct set of [[spectral line]]s
* 1861&nbsp;— [[Gustav Spörer]] discovers the variation of sun-spot [[latitude]]s during a solar cycle, explained by [[Spörer's law]]
* 1863&nbsp;— [[Richard Christopher Carrington|Richard Carrington]] discovers the differential nature of solar rotation
* 1868&nbsp;— [[Pierre Janssen]] and [[Norman Lockyer]] discover an unidentified yellow line in [[solar prominence]] spectra and suggest it comes from a new element which they name "[[helium]]"
* 1893&nbsp;— [[Edward Maunder]] discovers the 1645-1715 [[Maunder sunspot minimum]]