- 1613 – Galileo Galilei uses sunspot observations to demonstrate the
rotation of the Sun - 1619 – Johannes Kepler postulates a solar wind to explain the direction
of comet tails - 1802 – William Hyde Wollaston observes dark lines in the solar spectrum
- 1814 – Joseph Fraunhofer systematically studies the dark lines in the
solar spectrum - 1834 – Hermann Helmholtz proposes gravitational contraction as the
energy source for the Sun - 1843 – Heinrich Schwabe announces his discovery of the sunspot cycle
and estimates its period to be about ten years - 1852 – Edward Sabine shows that sunspot number is correlated with
geomagnetic field variations - 1859 – Richard Carrington discovers solar flares
- 1860 – Gustav Kirchhoff and Robert Bunsen discover that each chemical
element has its own distinct set of spectral lines and use this fact to
explain the solar dark lines - 1861 – F.G.W. Sporer discovers the variation of sun-spot latitudes
during a solar cycle - 1863 – Richard Carrington discovers the differential nature of solar
rotation - 1868 – Pierre-Jules-Cesar 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 – Edward Maunder discovers the 1645-1715 Maunder sunspot minimum
- 1904 – Edward Maunder plots the first sunspot “butterfly diagram
- 1906 – Karl Schwarzschild explains solar limb darkening
- 1908 – George Hale discovers the Zeeman splitting of spectral lines
from sunspots - 1942 – J.S. Hey detects solar radio waves
- 1949 – Herbert Friedman detects solar X-rays
- 1960 – Robert Leighton, Robert Noyes, and George Simon discover solar
five-minute oscillations by observing the Doppler shifts of solar dark
lines - 1961 – H. Babcock proposes the magnetic coiling sunspot theory
- 1970 – Roger Ulrich, John Leibacher, and Robert Stein deduce from
theoretical solar models that the interior of the Sun could act as a
resonant acoustic cavity - 1975 – Franz-Ludwig Deubner makes the first accurate measurements of
the period and horizontal wavelength of the five-minute solar
oscillations
Timeline of Solar Astronomy
