| 1774, March 4 | Herschel's first observation. Subject, the Orion Nebula. |
| 1774 | Sun-spots geometrically proved to be depressions by Wilson. |
| 1774 | First experimental determination of the earth's mean density by Maskelyne. |
| 1781, March 13 | Discovery of Uranus. |
| 1782 | Herschel's first Catalogue of Double Stars. |
| 1783 | Herschel's first investigation of the sun's movement in space. |
| 1783 | Goodricke's discovery of Algol's law of variation. |
| 1784 | Analogy between Mars and the Earth pointed out by Herschel. |
| 1784 | Construction of the Heavens investigated by Herschel's method of star-gauging. "Cloven-disc" plan of the Milky Way. |
| 1784 | Discovery of binary stars anticipated by Michell. |
| 1786 | Herschel's first Catalogue of Nebulæ. |
| 1787, Jan. 11 | Discovery by Herschel of two Uranian moons (Oberon and Titania). |
| 1787, Nov. 19 | Acceleration of the moon explained by Laplace. |
| 1789 | Herschel's second Catalogue of Nebulæ, and classification by age of these objects. |
| 1789 | Completion of Herschel's forty-foot reflector. |
1789, Aug. 28
and Sept. 17 | His discovery with it of the two inner Saturnian satellites. |
| 1789 | Repeating-circle invented by Borda. |
| 1789 | Five-foot circle constructed by Ramsden for Piazzi. |
| 1790 | Maskelyne's Catalogue of thirty-six fundamental stars. |
| 1791 | Herschel propounds the hypothesis of a fluid constitution for nebulæ. |
| 1792 | Atmospheric refraction in Venus announced by Schröter. |
| 1794 | Rotation-period of Saturn fixed by Herschel at 10h. 16m. |
| 1795 | Herschel's theory of the solar constitution. |
| 1796 | Herschel's first measures of comparative stellar brightness |
| 1796 | Laplace's Nebular Hypothesis published in Exposition du Système du Monde. |
| 1797 | Publication of Olbers's method of computing cometary orbits. |
| 1798 | Retrograde motions of Uranian satellites detected by Herschel. |
| 1799 | Publication of first two volumes of Mécanique Céleste. |
| 1799, May 7 | Transit of Mercury observed by Schröter. |
| 1799, Nov. 12 | Star-shower observed by Humboldt at Cumana. |
| 1800 | Monatliche Correspondenz started by Von Zach. |
| 1800 | Invisible heat-rays detected in the solar spectrum by Herschel. |
| 1801, Jan. 1 | Discovery of Ceres by Piazzi. |
| 1801 | Publication of Lalande's Histoire Céleste. |
| 1801 | Investigation by Herschel of solar emissive variability in connection with spot-development. |
| 1802, March 28 | Discovery of Pallas by Olbers. |
| 1802 | Herschel's third Catalogue of Nebulæ. |
| 1802 | Herschel's discovery of binary stars. |
| 1802 | Marks of clustering in the Milky Way noted by Herschel. |
| 1802 | Wollaston records seven dark lines in the solar spectrum. |
| 1802, Nov. 9 | Transit of Mercury observed by Herschel. |
| 1804, Sept. 2 | Transit of Mercury observed by Herschel. |
| 1804 | Foundation of Optical Institute at Munich. |
| 1805 | Herschel's second determination of the solar apex. |
| 1807, March 29 | Discovery of Vesta by Olbers. |
| 1811 | Herschel's theory of the development of stars from nebulæ. |
| 1811, Feb. 9 | Death of Maskelyne. Pond appointed to succeed him as Astronomer-Royal. |
| 1811, Sept. 12 | Perihelion passage of great comet. |
| 1814 | Herschel demonstrates the irregular distribution of stars in space. |
| 1815 | Fraunhofer maps 324 dark lines in the solar spectrum. |
| 1818 | Publication of Bessel's Fundamenta Astronomiæ. |
| 1819 | Recognition by Encke of the first short-period comet. |
| 1819, June 26 | Passage of the earth through the tail of a comet. |
| 1820 | Foundation of the Royal Astronomical Society. |
| 1821 | Foundation of Paramatta Observatory. |
| 1821, September | First number of Astronomische Nachrichten. |
| 1822, May 24 | First calculated return of Encke's comet. |
| 1822, August 25 | Death of Herschel. |
| 1823 | Bessel introduces the correction of observations for personal equation. |
| 1823 | Fraunhofer examines the spectra of fixed stars. |
| 1824 | Distance of the sun concluded by Encke to be 95-1/4 million miles. |
| 1824 | Publication of Lohrmann's Lunar Chart. |
| 1824 | Dorpat refractor mounted equatoreally. |
| 1826 | Commencement of Schwabe's observations of sun-spots. |
| 1826, Feb. 27 | Biela's discovery of a comet. |
| 1827 | Orbit of a binary star calculated by Savary. |
| 1829 | Completion of the Royal Observatory at the Cape of Good Hope. |
| 1829 | The Königsberg heliometer mounted. |
| 1830 | Publication of Bessel's Tabulæ Regiomontanæ. |
| 1832 | Discovery by Brewster of "atmospheric lines" in the solar spectrum. |
| 1833 | Magnetic observatory established at Göttingen. |
| 1833, Nov. 12, 13 | Star-shower visible in North America. |
| 1833 | Completion of Sir J. Herschel's survey of the northern heavens. |
| 1834, Jan. 16 | Sir J. Herschel's landing at the Cape. |
| 1835, September | Airy appointed Astronomer-Royal in succession to Pond. |
| 1835, Nov. 16 | Perihelion passage of Halley's comet. |
| 1837 | Solar movement determined by Argelander. |
| 1837 | Bessel's application of the heliometer to measurements of stellar parallax. |
| 1837 | Publication of Beer and Mädler's Der Mond. |
| 1837, Dec. 16 | Outburst of η Carinæ observed by Sir J. Herschel. |
| 1837 | Thermal power of the sun measured by Herschel and Pouillet. |
| 1838 | Parallax of 61 Cygni determined by Bessel. |
| 1839, Jan. 9 | Parallax of α Centauri announced by Henderson. |
| 1839 | Completion of Pulkowa Observatory. |
| 1839 | Solidity of the earth concluded by Hopkins. |
| 1840, March 2 | Death of Olbers. |
| 1840 | First attempt to photograph the moon by J. W. Draper. |
| 1842 | Doppler enounces principle of colour-change by motion. |
| 1842 | Conclusion of Baily's experiments in weighing the Earth. |
| 1842, July 8 | Total solar eclipse. Corona and prominences observed by Airy, Baily, Arago, and Struve. |
| 1843, Feb. 27 | Perihelion-passage of great comet. |
| 1845, February | Completion of Parsonstown reflector. |
| 1845, April | Discovery with it of spiral nebulæ. |
| 1845, April 2 | Daguerreotype of the sun taken by Foucault and Fizeau. |
| 1845, Oct. 21 | Place of Neptune assigned by Adams. |
| 1845, Dec. 8 | Discovery of Astræa by Hencke. |
| 1845, Dec. 29 | Duplication of Biela's comet observed at Yale College. |
| 1846 | Melloni's detection of heating effects from moonlight. |
| 1846, March 17 | Death of Bessel. |
| 1846, Sept. 23 | Discovery of Neptune by Galle. |
| 1846, Oct. 10 | Neptune's satellite discovered by Lassell. |
| 1847 | Publication of Sir J. Herschel's Results of Observations at the Cape of Good Hope. |
| 1847 | Cyclonic theory of sun-spots stated by him. |
| 1848 | J. R. Mayer's meteoric hypothesis of solar conservation. |
| 1848 | Motion-displacements of Fraunhofer lines adverted to by Fizeau. |
| 1848, April 27 | New Star in Ophiuchus observed by Hind. |
| 1848, Sept. 19 | Simultaneous discovery of Hyperion by Bond and Lassell. |
| 1849 | First experimental determination of the velocity of by Fizeau. |
| 1848, April 27 | New Star in Ophiuchus observed by Hind. |
| 1848, Sept. 19 | Simultaneous discovery of Hyperion by Bond and Lassell. |
| 1849 | First experimental determination of the velocity of light (Fizeau). |
| 1850, July 17 | Vega photographed at Harvard College. |
| 1850, Nov. 15 | Discovery by Bond of Saturn's dusky ring. |
| 1851 | O. Struve's first measurements of Saturn's ring-system |
| 1851, July 28 | Total solar eclipse observed in Sweden. |
| 1851, Oct. 24 | Discovery by Lassell of two inner Uranian satellites. |
| 1851 | Schwabe's discovery of sun-spot periodicity published by Humboldt. |
| 1852, May 6 | Coincidence of magnetic and sun-spot periods announced by Sabine. |
| 1852, Oct. 11 | Variable nebula in Taurus discovered by Hind. |
| 1852 | Lassell's two-foot reflector transported to Malta. |
| 1853 | Adams shows Laplace's explanation of the moon's acceleration to be incomplete. |
| 1854 | Hansen infers from lunar theory a reduced value for the distance of the sun. |
| 1854 | Helmholtz's "gravitation theory" of solar energy. |
| 1856 | Piazzi Smyth's observations on the Peak of Teneriffe. |
| 1857 | Saturn's rings shown by Clerk Maxwell to be of meteoric formation. |
| 1857, April 27 | Double-star photography initiated at Harvard College. |
| 1858 | Solar photography begun at Kew. |
| 1858, Sept. 30 | Perihelion of Donati's comet. |
| 1859 | Spectrum analysis established by Kirchhoff and Bunsen. |
| 1859 | Carrington's discovery of the compound nature of the sun's rotation. |
| 1859, Sept. 1 | Luminous solar outburst and magnetic storm. |
| 1859, Oct. 19 | Merope nebula discovered by Tempel. |
| 1859, Dec. 15 | Chemical constitution of the sun described by Kirchhoff. |
| 1860, Feb. 27 | Discovery by Liais of a "double comet." |
| 1860, May 21 | New star in Scorpio detected by Auwers. |
| 1860, July 18 | Total solar eclipse observed in Spain. Prominences shown by photography to be solar appendages. |
| 1861, June 30 | The earth involved in the tail of a great comet. |
| 1861-1862 | Kirchhoff's map of the solar spectrum. |
| 1862 | Solar hydrogen-absorption recognised by Ångström. |
| 1862, Jan. 31 | Discovery by Alvan G. Clark of the companion of Sirius. |
| 1862 | Foucault determines the sun's distance by the velocity of light. |
| 1862 | Opposition of Mars. Determination of solar parallax. |
| 1862 | Completion of Bonner Durchmusterung. |
| 1863 | Secchi's classification of stellar spectra. |
| 1863 | Foundation of the German Astronomical Society. |
| 1864, March 5 | Rotation period of Mars determined by Kaiser. |
| 1864 | Huggins's first results in stellar spectrum analysis. |
| 1864, Aug. 5 | Spectroscopic examination of Tempel's comet by Donati shows it to be composed of glowing gas. |
| 1864, Aug. 29 | Discovery by Huggins of gaseous nebulæ. |
| 1864 | Value of 91,000,000 miles adopted for the sun's distance. |
| 1864 | Croll's explanation of glacial epochs. |
| 1864, Nov. 23 | Death of Struve. |
| 1865, Jan. 4 | Spectroscopic observation by Huggins of the occultation of ε Piscium. |
| 1865, Jan. 16 | Faye's theory of the solar constitution. |
| 1865 | Kew results published. |
| 1865 | Zöllner argues for a high temperature in the great planets. |
| 1866 | Identity of the orbits of the August meteors and of comet 1862 iii. demonstrated by Schiaparelli. |
| 1866 | Delaunay explains lunar acceleration by a lengthening of the day through tidal friction. |
| 1866, March 4 | Spectroscopic study of the sun's surface by Lockyer. |
| 1866, March 12 | New star in Corona Borealis detected by Birmingham. |
| 1866, October | Schmidt announces the disappearance of the lunar crater Linné. |
| 1866, Nov. 13 | Meteoric shower visible in Europe. |
| 1867 | Period of November meteors determined by Adams. |
| 1867, Aug. 29 | Total solar eclipse. Minimum sun-spot type of corona observed by Grosch at Santiago. |
| 1867 | Discovery of gaseous stars in Cygnus by Wolf and Rayet. |
| 1868, February | Principle of daylight spectroscopic visibility of prominences started by Huggins. |
| 1868, Aug. 18 | Great Indian eclipse. Spectrum of prominences observed. |
| 1868, Aug. 19 | Janssen's first daylight view of a prominence. |
| 1868, Oct. 26 | Lockyer and Janssen independently announce their discovery of the spectroscopic method. |
| 1868 | Doppler's principle applied by Huggins to measure stellar radial movements. |
| 1868 | Publication of Ångström's map of the normal solar spectrum. |
| 1868 | Spectrum of Winnecke's comet found by Huggins to agree with that of olefiant gas. |
| 1869, Feb. 11 | Tenuity of chromospheric gases inferred by Lockyer and Frankland. |
| 1869, Feb. 13 | Huggins observes a prominence with an "open slit." |
| 1869, Aug. 7 | American eclipse. Detection of bright-line coronal spectrum. |
| 1870 | Mounting of Newall's 25-inch achromatic at Gateshead. |
| 1870 | Proctor indicates the prevalence of drifting movements among the stars. |
| 1870 | A solar prominence photographed by Young. |
| 1870, Dec. 22 | Sicilian eclipse. Young discovers reversing layer. |
| 1871, May 11 | Death of Sir J. Herschel. |
| 1871, June 9 | Line-displacements due to solar rotation detected by Vogel. |
| 1871, Dec. 12 | Total eclipse visible in India. Janssen observes reflected Fraunhofer lines in spectrum of corona. |
| 1872 | Conclusion of a three years' series of observations on lunar heat by Lord Rosse. |
| 1872 | Spectrum of Vega photographed by H. Draper. |
| 1872 | Faye's cyclonic hypothesis of sun-spots. |
| 1872 | Young's solar-spectroscopic observations at Mount Sherman. |
| 1872 | Cornu's experiments on the velocity of light. |
| 1872, Nov. 27 | Meteoric shower connected with Biela's comet. |
| 1873 | Determination of mean density of the earth by Cornu and Baille. |
| 1873 | Solar photographic work begun at Greenwich. |
| 1873 | Erection of 26-inch Washington refractor. |
| 1874 | Light-equation redetermined by Glasenapp. |
| 1874 | Vogel's classification of stellar spectra. |
| 1874, Dec. 8 | Transit of Venus. |
| 1876 | Publication of Neison's The Moon. |
| 1876, Nov. 24 | New star in Cygnus discovered by Schmidt. |
| 1876 | Spectrum of Vega photographed by Huggins. First use of dry gelatine plates in celestial photography. |
| 1877, May 19 | Klein observes a supposed new lunar crater (Hyginus N.). |
| 1877 | Measurement by Vogel of selective absorption in solar atmosphere. |
| 1877, Aug. 16-17 | Discovery of two satellites of Mars by Hall at Washington. |
| 1877, Sept. 23 | Death of Leverrier. |
| 1877 | Canals of Mars discovered by Schiaparelli. |
| 1877 | Opposition of Mars observed by Gill at Ascension. Solar parallax deduced = 8·78′. |
| 1878, January | Stationary meteor-radiants described by Denning. |
| 1878 | Publication of Schmidt's Charte der Gebirge des Mondes. |
| 1878 | First observations of Great Red Spot on Jupiter. |
| 1878 | Conclusion of Newcomb's researches on the lunar theory. |
| 1878, May 6 | Transit of Mercury. |
| 1878 | Foundation of Selenographical Society. |
| 1878, July 29 | Total eclipse visible in America. Vast equatoreal extension of the corona. |
| 1878, October | Completion of Potsdam Astrophysical Observatory. |
| 1878, Dec. 12 | Lockyer's theory of celestial dissociation communicated to the Royal Society. |
| 1879 | Michelson's experiments on the velocity of light. |
| 1879 | Publication of Gould's Uranometria Argentina. |
| 1879, November | Observations of the spectra of sun-spots begun at South Kensington. |
| 1879, Dec. 5 | Abney's map of the infra-red solar spectrum presented to the Royal Society. |
| 1879, Dec. 18 | Ultra-violet spectra of white stars described by Huggins. |
| 1879, Dec. 18 | Communication of G. H. Darwin's researches into the early history of the moon. |
| 1880, Jan. 31 | Discovery at Cordoba of a great southern comet. |
| 1880 | Conditions of Algol's eclipses determined by Pickering. |
| 1880 | Pickering computes mass-brightness of binary stars. |
| 1880, Sept. 30 | Draper's photograph of the Orion nebula. |
| 1880 | The bolometer invented by Langley. |
| 1881, Jan. 20 | Communication of G. H. Darwin's researches into the effects of tidal friction on the evolution of the solar system. |
| 1881 | Langley's observations of atmospheric absorption on Mount Whitney. |
| 1881, June 16 | Perihelion of Tebbutt's comet. |
| 1881, June 24 | Its spectrum photographed by Huggins. |
| 1881, June | Photographs of Tebbutt's comet by Janssen and Draper. |
| 1881, Aug. 15 | Retirement of Sir George Airy. Succeeded by Christie. |
| 1881, Aug. 22 | Perihelion of Schaeberle's comet. |
| 1881 | Publication of Stone's Cape Catalogue for 1880. |
| 1881 | Struve's second measures of Saturn's ring-system. |
| 1882 | Newcomb's determination of the velocity of light. Resulting solar parallax = 8·79′. |
| 1882 | Correction by Nyrén of Struve's constant of aberration. |
| 1882, March 7 | Spectrum of Orion nebula photographed by Huggins. |
| 1882, May 17 | Total solar eclipse observed at Sohag in Egypt. |
| 1882, May 27 | Sodium-rays observed at Dunecht in spectrum of Comet Wells. |
| 1882, June 10 | Perihelion of Comet Wells. |
| 1882, Sept. 17 | Perihelion of Great Comet. Daylight detection by Common. Transit observed at the Cape. |
| 1882, Sept. 18 | Iron lines identified in spectrum by Copeland and J. G. Lohse. |
| 1882, September | Photographs of comet taken at the Cape Observatory, showing a background crowded with stars. |
| 1882, Dec. 6 | Transit of Venus. |
| 1882 | Duplication of Martian canals observed by Schiaparelli. |
| 1882 | Completion by Loewy at Paris of first equatoreal Coudé. |
| 1882 | Rigidity of the earth concluded from tidal observations by G. H. Darwin. |
| 1882 | Experiments by Huggins on photographing the corona without an eclipse. |
| 1882 | Publication of Holden's Monograph of the Orion Nebula. |
| 1883, Jan. 30 | Orion Nebula photographed by Common. |
| 1883, May 6 | Caroline Island eclipse. |
| 1883, June 1 | Great comet of 1882 observed from Cordoba at a distance from the earth of 470 million miles. |
| 1883 | Parallaxes of nine southern stars measured by Gill and Elkin. |
| 1883 | Catalogue of the spectra of 4,051 stars by Vogel. |
| 1884, Jan. 25 | Return to perihelion of Pons's comet. |
| 1884 | Photometric Catalogue by Pickering of 4,260 stars. |
| 1884 | Publication of Gore's Catalogue of Variable Stars. |
| 1884 | Publication of Faye's Origine du Monde. |
| 1884, Oct. 4 | Eclipse of the moon. Heat-phases measured by Boeddicker at Parsonstown. |
| 1884 | Dunér's Catalogue of Stars with Banded Spectra. |
| 1884 | Backlund's researches into the movements of Encke's comet. |
| 1885, February | Langley measures the lunar heat-spectrum. |
| 1885 | Publication of Uranometria Nova Oxoniensis. |
| 1885, Aug. 17 | New star in Andromeda nebula discerned by Gully. |
| 1885, Sept. 5 | Thollon's drawing of the solar spectrum presented to the Paris Academy. |
| 1885, Sept. 9 | Solar eclipse visible in New Zealand. |
| 1885, Nov. 16 | Photographic discovery by Paul and Prosper Henry of a nebula in the Pleiades. |
| 1885, Nov. 27 | Shower of Biela meteors. |
| 1885 | Thirty-inch achromatic mounted at Pulkowa. |
| 1885 | Publication of Rowland's photographic map of the normal solar spectrum. |
| 1885 | Bakhuyzen's determination of the rotation period of Mars. |
| 1885 | Stellar photographs by Paul and Prosper Henry. |
| 1886, Jan. 26 | Spectra of forty Pleiades simultaneously photographed at Harvard College. |
| 1886, Feb. 5 | First visual observation of the Maia nebula with Pulkowa 30-inch refractor. |
| 1886, March | Photographs by the Henrys of the Pleiades, showing 2,326 stars with nebulæ intermixed. |
| 1886, May | Photographic investigations of stellar parallax undertaken by Pritchard. |
| 1886, May 6 | Periodical changes in spectra of sun-spots announced by Pritchard. |
| 1886, June 4 | An international Photographic Congress proposed by Gill. |
| 1886, Aug. 29 | Total eclipse of the sun observed at Grenada. |
| 1886, Oct. 1 | Roberts's photograph showing annular structure of the Andromeda nebula. |
| 1886, Dec. 8 | Roberts's photograph of the Pleiades nebulosities. |
| 1886 | Solar heat-spectrum extended by Langley to below five microns. |
| 1886, Dec. 28 | Detection by Copeland of helium-ray in spectrum of the Orion nebula. |
| 1886 | Thirty-inch refractor mounted at Nice. |
| 1886 | Publication of Argentine General Catalogue. |
| 1886 | Completion of Auwers's reduction of Bradley's observations. |
| 1886 | Draper Memorial photographic work begun at Harvard College. |
| 1886 | Photographic detection at Harvard College of bright hydrogen lines in spectra of variables (Mira Ceti and U Orionis). |
| 1887, Jan. 18 | Discovery by Thome at Cordoba of a great comet belonging to the same group as the comet of 1882. |
| 1887 | Publication of Lockyer's Chemistry of the Sun. |
| 1887, April 16 | Meeting at Paris of the International Astrophotographic Congress. |
| 1887 | Heliometric triangulation of the Pleiades by Elkin. |
| 1887 | L. Struve's investigation of the sun's motion, and redetermination of the constant of precession. |
| 1887 | Von Konkoly's extension to 15° S. Dec. of Vogel's spectroscopic Catalogue. |
| 1887 | Auwers's investigation of the solar diameter. |
| 1887 | Publication of Schiaparelli's Measures of Double Stars (1875-85). |
| 1887, April 8 | Death of Thollon at Nice. |
| 1887, Aug. 19 | Total eclipse of the sun. Shadow-path crossed Russia. Observations marred by bad weather. |
| 1887, November | Langley's researches on the temperature of the moon. |
| 1887, Nov. 17 | Lockyer's Researches on Meteorites communicated to the Royal Society. |
| 1887 | Completion of 36-inch Lick refractor. |
| 1888 | Küstner's detection of variations in the latitude of Berlin brought before the International Geodetic Association. |
| 1888 | Chandler's first Catalogue of Variable Stars. |
| 1888 | Mean parallax of northern first magnitude stars determined by Elkin. |
| 1888 | Publication of Dreyer's New General Catalogue of 7,844 nebulæ. |
| 1888 | Vogel's first spectrographic determinations of stellar radial motion. |
| 1888 | Carbon absorption recognised in solar spectrum by Trowbridge and Hutchins. |
| 1888, Jan. 28 | Total eclipse of the moon. Heat-phases measured at Parsonstown. |
| 1888, Feb. 5 | Remarkable photograph of the Orion nebula spectrum taken at Tulse Hill. |
| 1888, June 1 | Activity of the Lick Observatory begun. |
| 1888 | Completion of Dr. Common's 5-foot reflector. |
| 1888 | Heliometric measures of Iris for solar parallax at the Cape, Newhaven (U.S.A.), and Leipsic. |
| 1888 | Loewy describes a comparative method of determining constant of aberration. |
| 1888 | Presentation of the Dunecht instrumental outfit to the nation by Lord Crawford. Copeland succeeds Piazzi Smyth as Astronomer-Royal for Scotland. |
| 1888, Sept. 12 | Death of R. A. Proctor. |
| 1889 | Photograph of the Orion nebula taken by W. H. Pickering, showing it to be the nucleus of a vast spiral. |
| 1889 | Discovery at a Harvard College of the first-known spectroscopic doubles, ζ Ursæ Majoris and β Aurigæ. |
| 1889 | Eclipses of Algol demonstrated spectrographically by Vogel. |
| 1889 | Completion of photographic work for the Southern Durchmusterung. |
| 1889 | Boeddicker's drawing of the Milky Way. |
| 1889 | Draper Memorial photographs of southern star-spectra taken in Peru. |
| 1889 | Pernter's experiments on scintillation from the Sonnblick. |
| 1889 | H. Struve's researches on Saturn's satellites. |
| 1889 | Harkness's investigation of the masses of Mercury, Venus, and the Earth. |
| 1889 | Heliometric measures of Victoria and Sappho at the Cape. |
| 1889, Jan. 1 | Total solar eclipse visible in California. |
| 1889, Feb. 7 | Foundation of the Astronomical Society of the Pacific. |
| 1889, March | Investigation by Sir William and Lady Huggins of the spectrum of the Orion nebula. |
| 1889, July-Aug. | First photographs of the Milky Way taken by Barnard. |
| 1889, August 2 | Observation by Barnard of four companions to Brooks's comet. |
| 1889, Nov. 1 | Passage of Japetus behind Saturn's dusky ring observed by Barnard. |
| 1889, December | Schiaparelli announces synchronous rotation and revolution of Mercury. |
| 1889, Dec. 22 | Total eclipse of the sun visible in Guiana. Death of Father Perry, December 27. |
| 1889 | Spectrum of Uranus investigated visually by Keeler, photographically by Huggins. |
| 1890 | Long-exposure photographs of ring-nebula in Lyra. |
| 1890 | Determinations of the solar translation by L. Boss and O. Stumpe. |
| 1890 | Schiaparelli finds for Venus an identical period of rotation and revolution. |
| 1890 | Publication of Thollon's map of the solar spectrum. |
| 1890 | Bigelow's mathematical theory of coronal structures. |
| 1890 | Foundation of the British Astronomical Association. |
| 1890 | Measurements by Keeler at Lick of nebular radial movements. |
| 1890 | Janssen's ascent of Mont Blanc, by which he ascertained the purely terrestrial origin of the oxygen-absorption in the solar spectrum. |
| 1890 | Newcomb's discussion of the transits of Venus of 1761 and 1769. |
| 1890 | Spiral structure of Magellanic Clouds displayed in photographs taken by H. C. Russell of Sydney. |
| 1890 | Publication of the Draper Catalogue of Stellar Spectra. |
| 1890, April 24 | Spica announced by Vogel to be a spectroscopic binary. |
| 1890, June | Gore's Catalogue of computed Binaries. |
| 1890, November | Study by Sir William and Lady Huggins of the spectra of Wolf and Rayet's stars in Cygnus. |
| 1890, November | Discovery by Barnard of a close nebulous companion to Merope in the Pleiades. |
| 1890, November | McClean Spectrographs of the High and Low Sun. |
| 1891 | Capture-theory of comets developed by Callandreau, Tisserand, and Newton. |
| 1891 | Dunér's spectroscopic researches on the sun's rotation. |
| 1891 | Preponderance of Sirian stars in the Milky Way concluded by Pickering, Gill, and Kapteyn. |
| 1891 | Detection by Mrs. Fleming of spectral variations corresponding to light-changes in β Lyræ. |
| 1891 | Establishment of the Harvard College Station at Arequipa in Peru (height 8,000 feet). |
| 1891 | Variations of latitude investigated by Chandler. |
| 1891 | Prominence-photography set on foot by Hale at Chicago and Deslandres at Paris. |
| 1891 | Schmidt's Theory of Refraction in the Sun. |
| 1891, April | Meeting at Paris of the Permanent Committee for the Photographic Charting of the Heavens. |
| 1891, May 9 | Transit of Mercury. |
| 1891, Aug. 19 | Presidential Address by Huggins at the Cardiff Meeting of the British Association. |
| 1891, Dec. 10 | Nova Aurigæ photographed at Harvard College. |
| 1891, Dec. 20 | Photographic maximum of Nova Aurigæ. |
| 1891, Dec. 22 | First photographic discovery of a minor planet by Max Wolf at Heidelberg. |
| 1892 | Commencement of international photographic charting work. |
| 1892 | Photographic determination by Scheiner of 833 stars in the Hercules Cluster (M 13). |
| 1892 | Publication of Vogel's spectrographic determinations for fifty-one stars. |
| 1892 | Publication of Pritchard's photographic parallaxes. |
| 1892, Jan. 2 | Death of Sir George Airy. |
| 1892, Jan. 21 | Death of Professor Adams. |
| 1892, Feb. 1 | Announcement by Anderson of the outburst of a new star in Auriga. |
| 1892, Feb. 5 | Appearance of the largest sun-spot ever photographed at Greenwich. |
| 1892, March | Photograph of Argo nebula taken by Gill in twelve hours. |
| 1892, March 6 | Discovery of a bright comet by Swift. |
| 1892, June 29 | Death of Admiral Mouchez. Succeeded by Tisserand as director of the National Observatory, Paris. |
| 1892, Aug. 4 | Favourable Opposition of Mars. |
| 1892, Aug. 17 | Rediscovery at Lick of Nova Aurigæ. |
| 1892, Sept. 9 | Discovery by Barnard of Jupiter's inner satellite. |
| 1892, Oct. 12 | First photographic discovery of a comet by Barnard. |
| 1892, Nov. 6 | Discovery of Holmes's comet. |
| 1892, Nov. 23 | Shower of Andromede meteors visible in America. |
| 1892 | Poynting's Determination of the Earth's Mean Density. |
| 1892 | Dunér's Investigation of the System of Υ Cygni. |
| 1892 | Photographic investigation by Deslandres of the spectra of prominences. |
| 1892 | Photographs of the sun with faculæ and chromospheric surroundings taken by Hale with a single exposure. |
| 1892 | Investigation by T. J. J. See of the ancient colour of Sirius. |
| 1892 | Publication of T. J. J. See's Thesis on the Evolution of Binary Systems. |
| 1892 | Chandler's theory of Algol's inequalities. |
| 1892 | Nebula in Cygnus photographically discovered by Max Wolf. |
| 1893, Jan. 28 | Kapteyn's investigation of the structure of the universe. |
| 1893, March 10 | Gill announces his results from the Opposition of Victoria, among them a solar parallax = 8·809′. |
| 1893, April 16 | Total solar eclipse observed in South America and West Africa. |
| 1893 | Publication of Kruger's Catalog der Farbigen Sterne. |
| 1893 | Conclusion of Boys's series of Experiments on the Density of the Earth. |
| 1893 | Publication of Cordoba Durchmusterung, vol. i. |
| 1893 | Fabry shows comets to be dependents of the Solar System. |
| 1893 | Publication of Easton's Voie Lactée. |
| 1893 | Campbell detects bright Hα in γ Argûs and Alcyone. |
| 1893 | Nova Normæ photographed July 10; discovered on plates, October 26. |
| 1893, May 28 | Death of Professor Pritchard. |
| 1893, July 27 | Installation of 28-inch refractor at the Royal Observatory, Greenwich. |
| 1893, December | Exterior nebulosities of Pleiades photographed by Barnard. |
| 1893, Dec. 6 | Death of Rudolf Wolf. |
| 1894, January | Sun-spot maximum. |
| 1894 | Publication of Potsdam Photometric Durchmusterung, part i. |
| 1894 | Publication of Roberts's Celestial Photographs, vol. i. |
| 1894 | Wilson and Gray's determination of the sun's temperature. |
| 1894 | Barnard's micrometric measures of asteroids. |
| 1894 | McClean's gift of an astrophysical outfit to the Cape Observatory. |
| 1894 | Establishment of the Lowell Observatory at Flagstaff, Arizona. |
| 1894 | Taylor's triple achromatic objective described. |
| 1894, April 3 | Discovery of Gale's Comet. |
| 1894 | Sampson's investigation of the sun's rotation. |
| 1894, Oct. 20 | Favourable opposition of Mars. |
| 1894, Nov. 11 | Transit of Mercury. |
| 1894, December | Howlett impugns the Wilsonian theory of sun-spots. |
| 1894, Dec. 14 | Death of A. Cowper Ranyard. |
| 1895 | Publication of Newcomb's Astronomical Constants. |
| 1895 | Bailey's Photometric Catalogue of 7,922 Southern Stars. |
| 1895 | Bailey's photographic discovery of variable star clusters. |
| 1895 | Publication of E. W. Brown's Lunar Theory. |
| 1895 | Tisserand's theory of the inequalities of Algol. |
| 1895 | Stratonoff's determination of the sun's rotation from photographs of faculæ. |
| 1895 | Binary character of η Aquilæ spectroscopically recognised by Bélopolsky. |
| 1895 | Presentation of the Crossley reflector to the Lick Observatory. |
| 1895, March 23 | Great nebula in Ophiuchus discovered photographically by Barnard. |
| 1895, March 25 | Ramsay's capture of Helium. |
| 1895, April | Constitution of Saturn's rings spectrographically demonstrated by Keeler. |
| 1895 | Binary character of δ Cephei spectroscopically detected by Bélopolsky. |
| 1895, June 11 | Death of Daniel Kirkwood. |
| 1895, July 7 | Death of F. W. G. Spörer. |
| 1895, October | Nova Carinæ spectrographically discovered by Mrs. Fleming. |
| 1895, Dec. 12 | Nova Centauri spectrographically discovered by Mrs. Fleming. |
| 1895, Dec. 28 | Death of John Russell Hind. |
| 1896 | Gill's Report on the Geodetic Survey of South Africa. |
| 1896 | Appearance of Loewy's Photographic Atlas of the Moon, part i. |
| 1896, January | Fessenden's electrostatic theory of comets. |
| 1896 | Chandler's Third Catalogue of Variable Stars. |
| 1896 | Publication of Lick Observatory Photographic Atlas of the Moon, part i. |
| 1896, February | Effects of pressure on wave-length described by Humphreys and Mohler. |
| 1896, April 5 | Opening of new Scottish Royal Observatory on Blackford Hill, Edinburgh. |
| 1896, April | Pickering's photometric determinations of light curves of variable stars. |
| 1896 | One of the stars of Castor spectroscopically resolved into two by Bélopolsky. |
| 1896, May | Third Astrographic Chart Conference at Paris. |
| 1896, Aug. 9 | Total eclipse of the sun visible in Novaya Zemlya. Reversing layer photographed by Shackleton. |
| 1896, Aug. 30 | Death of Hubert A. Newton. |
| 1896, Sept. 18 | Death of Hippolyte Fizeau. |
| 1896, Oct. 20 | Death of F. Tisserand. Succeeded by Maurice Loewy. |
| 1896, Nov. 13 | Detection by Schaeberle of Procyon's missing satellite. |
| 1896, Nov. 26 | Death of Benjamin Apthorp Gould. |
| 1896, November | Second series of hydrogen-lines discovered by Pickering in stellar spectra. |
| 1896, December | Zeeman's discovery of spectral modifications through magnetic influence. |
| 1896, December | Oxygen-absorption identified in the sun by Runge and Paschen. |
| 1896 | Study of lunar formations by Loewy and Puiseux. |
| 1896 | Mounting of the Mills spectrograph at the Lick Observatory. |
| 1897 | Installation at Greenwich of the Thompson 26-inch photographic refractor. |
| 1897 | Publication of Miss Maury's Discussion of the Photographed Spectra of 681 Stars. |
| 1897 | Callandreau's researches on cometary disaggregation. |
| 1897 | Braun's determination of the earth's mean density. |
| 1897 | Tenuity of calcium vapour in chromosphere demonstrated spectroscopically by Sir William and Lady Huggins. |
| 1897 | Completion at the Cape Observatory of McClean's spectrographic survey of the heavens. |
| 1897 | Twenty-one Wolf-Rayet stars found by Mrs. Fleming in Magellanic Cloud. |
| 1897 | Percival Lowell's New Observations on the Planet Mercury presented to the American Academy. |
| 1897, April 8 | McClean recognises oxygen-absorption in helium stars. |
| 1897, May 9 | Death of E. J. Stone, Radcliffe Observer. |
| 1897, June 10 | Death of Alvan G. Clark. |
| 1897, June 18 | Spectrum of a meteor photographed at Arequipa. |
| 1897, Oct. 21 | Inauguration of the Yerkes Observatory. |
| 1897 | Rabourdin's photographs of nebulæ with the Meudon reflector. |
| 1897 | Dr. See's discoveries of Southern double stars with the Lowell 24-inch refractor. |
| 1898, Jan. 22 | Total eclipse of the sun visible in India. |
| 1898, February | Binary character of ζ Geminorum ascertained spectroscopically by Bélopolsky. |
| 1898 | Star with proper motion of nearly 9′ discovered by Innes and Kapteyn from the Cape Durchmusterung plates. |
| 1898, March 8 | Nova Sagittarii photographed on Draper Memorial plates. |
| 1898, June 20 | Opening of Grand-ducal Observatory at Königsstuhl, Heidelberg. |
| 1898 | Keeler succeeds Holden as Director of the Lick Observatory. |
| 1898 | Bruno Peter's results in stellar parallax. |
| 1898 | Lewis Swift's discoveries of nebulæ at Echo California. |
| 1898 | Hale's photographic investigation of carbon stars. |
| 1898, Aug. 14 | Discovery of Eros by Witt. |
| 1898 | Flint's investigations of stellar parallax by meridian differences. |
| 1898 | Easton's spiral theory of the Milky Way. |
| 1898 | Seeliger's research on star distribution. |
| 1898, October | Multiple hydrogen-bands observed by Campbell in Mira Ceti. |
| 1898, November | Orbit of a Leonid meteor photographically determined by Elkin. |
| 1899 | Publication of Potsdam Photometric Durchmusterung, part ii. |
| 1899 | Innes's Reference Catalogue of Southern Double Stars. |
| 1899 | Keeler's photographs of nebulæ with the Crossley reflector and generalization of their spiral character. |
| 1899, January | Spectrum of Andromeda nebula photographed by Scheiner. |
| 1899, April | Photographic discovery of Nova Aquilæ by Mrs. Fleming. |
| 1899, Aug. 26 | Installation of 31-inch photographic refractor at Potsdam. |
| 1899 | Campbell's detection of Polaris as spectroscopically triple. |
| 1899, October | Duplicate discovery by Campbell and Newall of Capella as a spectroscopic binary. |
| 1899, Nov. 15 | Failure of the Leonids. Deflection of the stream predicted by Johnstone Stoney and Downing. |
| 1899, December | Publication of Sir William and Lady Huggins's Atlas of Representative Stellar Spectra. |
| 1899 | Thirty-two-inch photographic refractor mounted at Meudon. |
| 1899 | Issue of first volume of Potsdam measures of international catalogue plates. |
| 1900, Jan. 27 | Kapteyn's determination of the apex of solar motion. |
| 1900 | Chase's measures for parallax of swiftly-moving stars. |
| 1900 | Publication of Gill's Researches on Stellar Parallax. |
| 1900 | Kapteyn proposes a method for a stellar parallax Durchmusterung, and gives specimen results for 248 stars. |
| 1900 | Burnham's general catalogue of 1,290 double stars. |
| 1900 | Publication of the concluding volume of the Cape Photographic Durchmusterung. |
| 1900, May 28 | Spanish-American total eclipse of the sun. |
| 1900, July | International Conference at Paris. Co-operation arranged of fifty-eight observatories in measures of Eros for solar parallax. |
| 1900 | Horizontal refractor, of 50 inches aperture, 197 feet focus, installed in Paris Exhibition. |
| 1900, Aug. 12 | Death of Professor Keeler. Succeeded by Campbell in direction of Lick Observatory. |
| 1900, November | Opposition of Eros. |
| 1900 | Publication of Roberts's Celestial Photographs, vol. ii. |
| 1900 | Complete publication of Langley's researches on infra-red spectrum. |
| 1900 | Printing begun of Paris section of International Photographic Catalogue. |
| 1901, Feb. 22 | Nova Persei discovered by Anderson. |
| 1901, February | Variability of Eros announced by Oppolzer. |
| 1901, April 23 | Apparition of a great comet at the Cape. |
| 1901 | Publication of Pickering's Photometric Durchmusterung. |
| 1901 | Miss Cannon's discussion of the spectra of 1,122 Southern stars. |
| 1901 | Kapteyn's investigation of mean stellar parallax. |
| 1901 | Campbell's determination of the sun's velocity. |
| 1901 | Porter's research on the solar motion in space. |
| 1901 | Bigelow's magnetic theory of the solar corona. |
| 1901 | Hussey's measurements of the Pulkowa double stars. |
| 1901 | Radial velocities of the components of δ Equulei measured at Lick. |
| 1901, April 16 | Death of Henry A. Rowland. |
| 1901, June | Nebular spectrum derived from Nova Persei. |
| 1901, Aug. 23 | Nebula near Nova Persei photographed by Max Wolf. |
| 1901, Sept. 20 | The same exhibited in spiral form on a plate taken by Ritchey at the Yerkes Observatory. |
| 1901, Nov. 8 | Photograph taken by Perrine with the Crossley reflector showed nebula in course of rapid change. |
| 1901, Sept. 19 | Unveiling of the McClean "Victoria" telescope at the Royal Observatory, Cape of Good Hope. |
| 1901 | Sun-spot minimum. |
CHEMICAL ELEMENTS IN THE SUN (ROWLAND, 1891).
Arranged according to the number of their representative Lines in the Solar Spectrum.