December 10, 2018 - An Astronomical Achievement

An Astronomical Achievement Developing a scheme to categorize the countless stars in the sky was a daunting task, but it was accomplished by one of the most famous women astronomers, Annie Jump Cannon, born 155 years ago this week. A Wellesley graduate, Cannon joined the Harvard College Observatory staff in 1896 to help develop a meaningful way to classify stars according to their spectra. For the next forty years, Cannon studied spectroscopic images of over 250,000 stars and devised the O,B,A,F,G,K,M system of classifying stars that is still in use today. Her work was eventually published in the nine-volume Henry Draper Catalog (named after the project benefactor). Seen here, a variety of stars of many different spectral types are visible within the swaddling dust of the Serpens Cloud Core.

Image credit: NASA/JPL-Caltech/2MASS

Weekly Calendar

December 10 - 16, 2018

Holidays - Sky Events - Space History

Monday 10

1963: Dyna-Soar project canceled
1999: Newton X-Ray Multi-Mirror Telescope launched

Tuesday 11

1863: Annie Jump Cannon born
1972: Apollo 17 lands on Moon
1993: Sotheby’s holds first auction of Soviet space hardware & artifacts

Wednesday 12

Moon at apogee

1961: OSCAR 1 launched, first amateur radio satellite
1970: Italian ground crew becomes first to launch satellite for America, Explorer 42
2017: North Korea launches first satellite, KMS 3-2