1814 – Born on the 13th of August in Sweden.
1839 – He was educated at Uppsala University, where he became docent in physics.
1842 – He went to the Stockholm Observatory in order to gain experience in practical astronomical work, and in the following year he was appointed keeper of the Uppsala Astronomical Observatory.
1851-1853 – Becoming interested in terrestrial magnetism he made many observations of magnetic intensity and declination in various parts of Sweden, and was charged by the Stockholm Academy of Sciences with the task, not completed till shortly before his death, of working out the magnetic data obtained by the Swedish frigate "Eugénie" on her voyage round the world.
1853 – In his optical researches, Optiska Undersökningar, presented to the Royal Swedish Academy of Sciences.
1858 – He succeeded Adolph Ferdinand Svanberg in the chair of physics at Uppsala.
1861 – He paid special attention to the solar spectrum.
1862 – His combination of the spectroscope with photography for the study of the solar system resulted in proving that the sun’s atmosphere contains hydrogen, among other elements.
1867 – He was the first, to examine the spectrum of the aurora borealis, and detected and measured the characteristic bright line in its yellow green region; but he was mistaken in supposing that this same line, which is often called by his name, is also to be seen in the zodiacal light.
1868 – He published his great map of the normal solar spectrum in Recherches sur le spectre solaire, including detailed measurements of more than 1000 spectral lines, which long remained authoritative in questions of wave-length, although his measurements were inexact to the extent of one part in 7000 or 8000 owing to the metre which he used as his standard having been slightly too short.
1872 – As Sir Edward Sabine remarked when awarding him the Rumford medal of the Royal Society.
1874 – Died on the 21st of June in Uppsala, Sweden.