Cannon, Annie

In this chapter I ve mentioned U.S. astronomers Cecilia Payne-Gaposchkin and Annie J. Cannon. These are just two of numerous women who contributed immensely to the field of astronomy. Table 3.2 lists several more. 

Annie Jump Cannon (1863-1941) American astronomer who classified stellar spectra. Discovered hundreds of variable stars and five novae. 

Scientific work can be classified into two general categories collecting and collating data, and drawing conclusions and building theories based on those data. Neither activity can be conducted without the other, and either, in and of itself, is incomplete. One of the great data collectors and collators in the history of astronomy was Annie Jump Cannon, who came to astronomy somewhat late in life, at the age of 31. 

Annie Cannon was born on December 11,1863, in Dover, Delaware, to a prosperous shipbuilder and state senator, Wilson Cannon, and his second wife, Mary Jump. Cannon started her educational career with a serious handicap She was very hard of hearing. Still, she enrolled at Wellesley College in 1880 and earned her degree in physics four years later. She was primarily interested in astronomy, rather than physics, but a degree in that field was not then available. 

Early astronomers also knew that stars seemed to have different colors, hut a system for classifying stars on the basis of color was not proposed until about 1872. That system was proposed hy the American astronomer Henry Draper (1836-82). Draper s system of classification was very important because a star s color is an indication of its second major property, its temperature. The hotter a star, the more likely its color is to be in the blue to white range. The cooler the star, the more likely it is to emit an orangish or reddish color. Draper died before he could complete his system of star classification. The project was completed between 1918 and 1924 by the American astronomer Annie Jump Cannon (1863-1941). 

Annie Jump Cannon died on April 13, 1941, in Cambridge, just a year after her retirement from Harvard. 

MARK-9 AND MARK-19 280-MM PROJECTILES. The U S. mili tary fielded two nuclear projectiles for Atomic Annie, its 280-mm atomic cannon. The Matk-9 (Mk-9), having a range of about 15 miles, was test-fired successfully on 25 May 1953 during Shot Grable at Frenchman Flats, Nevada. Its weight and poor aerodynamics spurred development of a replacement, the Mark-19 (Mk-19), which was 200 pounds lighter and had a range of nearly 19 miles. 

SHOT GRABLE. On 25 May 1953, the U.S. military successfully fired a 280-mm nuclear weapon from an atomic cannon during Shot Grable of the Upshot-Knothole test series. A Mark-9 280-mm projectile traveled seven miles and detonated slightly more than 500 feet above ground, with a yield of 15 kilotons. See also ATOMIC ANNIE. 

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