* Astronomy

The first synthetic diamonds were produced in 1953
http://astronomy.activeboard.com/t2971800/the-diamond-age/

The excavation of "Cave 1" at Qumran began on 15 February 1949
http://en.wikipedia.org/wiki/Dead_Sea_Scrolls#Search_for_the_Qumran_caves_.281948.E2.80.931949.29

The Royal Observatory, Greenwich underwent an attempted bombing on 15 February 1894
http://en.wikipedia.org/wiki/Royal_Observatory,_Greenwich#Bomb_attack_of_1894

The Allegheny Observatory was founded on February 15, 1859
http://en.wikipedia.org/wiki/Allegheny_Observatory

On February 15, 1954, Canadian and American governments agreed to build a third DEW line of radar stations
http://en.wikipedia.org/wiki/Distant_Early_Warning_Line#Development_and_construction

Leland Devon Melvin (February 15, 1964) is an American engineer and a NASA astronaut.
http://astronomy.activeboard.com/t12372280/leland-melvin/

Roger Bruce Chaffee (February 15, 1935 - January 27, 1967), Lieutenant Commander, United States Navy, was a Naval Aviator
http://astronomy.activeboard.com/t47829390/roger-bruce-chaffee-1935-1967/

Herman Kahn (February 15, 1922 - July 7, 1983) was one of the preeminent futurists
http://en.wikipedia.org/wiki/Herman_Kahn

George Johnstone Stoney (15 February 1826 - 5 July 1911) was an Anglo-Irish physicist
http://en.wikipedia.org/wiki/George_Johnstone_Stoney

Spiru C. Haret (15 February 1851 - 17 December 1912) was a Romanian-Armenian mathematician
http://en.wikipedia.org/wiki/Spiru_Haret

William Fishburn Donkin FRS (1814 - 1869) was an astronomer and mathematician
http://en.wikipedia.org/wiki/William_Fishburn_Donkin

Galileo Galilei (15 February 1564 - 8 January 1642), was an Italian physicist
http://astronomy.activeboard.com/t14080040/galileo-galilei/

Malcolm Hartley (born 15 February 1947) is an English-born astronomer
https://en.wikipedia.org/wiki/Malcolm_Hartley

William Henry Pickering (February 15, 1858 - January 16, 1938) was an American astronomer
http://en.wikipedia.org/wiki/William_Henry_Pickering

Wallace Leslie William Sargent (February 15, 1935 - October 29, 2012) was a British-born American astronomer
http://en.wikipedia.org/wiki/Wallace_L._W._Sargent

Mildred Shapley Matthews (February 15, 1915 - February 11, 2016) was an American astronomer and editor of many astronomy books.
http://astronomy.activeboard.com/t59622320/mildred-shapley-matthews/

Emmanuel Liais (15 February 1826 - 5 March 1900) was a French astronomer, botanist and explorer 
http://en.wikipedia.org/wiki/Emmanuel_Liais

Sir Ernest Henry Shackleton, (15 February 1874 - 5 January 1922) was an Anglo-Irish polar explorer
http://astronomy.activeboard.com/t47829389/sir-ernest-henry-shackleton-1874-1922/

NGC 1647 was discovered by William Herschel on the 15th February 1784. 
http://astronomy.activeboard.com/t56731883/ngc-1647/

NGC 2455 was discovered by John Herschel on the 15th February 1836. 
http://astronomy.activeboard.com/t56731831/ngc-2455/

NGC 3226 was discovered by William Herschel on the 15th February 1784.
http://astronomy.activeboard.com/t61211754/ngc-3226/

NGC 3227 was discovered by William Herschel on the 15th February 1784.
http://astronomy.activeboard.com/t49519776/ngc-3227/

NGC 3632 was discovered by William Herschel on the 15th February 1784. 
http://astronomy.activeboard.com/t56731806/ngc-3632/

NGC 3646 was discovered by William Herschel on the 15th February 1784. 
http://astronomy.activeboard.com/t56731775/ngc-3646/

The Cat's Eye Nebula or NGC 6543 was discovered by William Herschel on February 15, 1786
http://en.wikipedia.org/wiki/Cat%27s_Eye_Nebula