Crédits : Sweeper in the Sky: The Life of Maria Mitchell, First Woman Astronomer in America by Helen Wright, 1914-1997. New York: The Macmillan Company, 1949. (Copyright was not renewed; therefore Sweeper in the Sky is in the public domain in the United States.) However, please note that the copyright status of the Maria Mitchell portrait is NOT determined by its publication in Sweeper in the Sky. As an image of a two-dimensional work of art, the work of art having been created in 1851, this is a public domain image according to Wikipedia's guidelines. Licence : Public domain
