Henrietta Swan Leavitt, American astronomer and academic (born 1868)

Henrietta Swan Leavitt was an American astronomer. Her discovery of how to effectively measure vast astronomical distances led to a shift in the understanding of the scale and nature of the universe. Nomination of Leavitt for the Nobel Prize had to be halted because of her death.

December 12 is the 346th day of the year in the Gregorian calendar; 19 days remain until the end of the year.