The first binary star system to be discovered, Xi Ursae Majoris, is found by William Herschel.
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278 years ago, in 1661:
Christiaan Huygens observes the planet Mercury transit the Sun.
224 years ago, in 1715:
During an eclipse in England, Edmond Halley is the first to report the phenomenon later known as Baily's Beads.
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186 years ago, in 1753:
Charles Messier makes his first documented observation; the Mercury transit of the Sun.
21 years ago, in 1918:
The 72 inch Plaskett telescope at The Dominion Astrophysical Observatory in Saanich, British Columbia sees first light.
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17 years ago, in 1922:
Tthe IAU passes a resolution to formally adopt Annie Jump Cannon's stellar classification system.
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158 years ago, in 1781:
The Sombrero Galaxy (M104) is discovered by Pierre Méchain.
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9 years ago, in 1930:
The first planetarium in the United States, Adler Planetarium in Chicago, is opened to the public.
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206 years ago, in 1733:
Birger Wassenius of Sweden, observing an eclipse near Göteborg, is the first to report prominences visible to the unaided eye; he incorrectly attributes them to the Moon.
78 years ago, in 1861:
John Tebbutt of Australia discovers the Great Comet of 1861 (C/1861 J1).
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57 years ago, in 1882:
On an expedition in Egypt , Dr. Arthur Schuster sees a comet (Tewfik) near the Sun during a total eclipse.
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155 years ago, in 1784:
William Herschel discovers NGC 6287, a globular cluster in the constellation Ophiuchus.
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155 years ago, in 1784:
William Herschel discovers NGC 6284, a globular cluster in the constellation Ophiuchus.
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396 years ago, in 1543:
Nicolaus Copernicus dies at age 70 in Frauenburg, Royal Prussia, Kingdom of Poland.
104 years ago, in 1835:
John Herschel discovers NGC 6325, a globular cluster in the constellation Ophiuchus.
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20 years ago, in 1919:
Arthur Eddington confirms Einstein's theory of general relativity during a total solar eclipse.
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4 years ago, in 1935:
The David Dunlap Observatory in Richmond Hill, Ontario, housing a 74-inch (1.88 m) reflector telescope (still the largest in Canada), has its official opening .
It's been 3977 days
