Anders Planman also calculated the correct longitude for six locations on the way, among them Kajaani, Mikkeli and Hämeenlinna. He could do this partly because he used surveying tools for his astronomical observations; these were some of the most exact contemporary measuring tools. The minor planet 2639 Planman is named after Anders Planman. Anders Planman Anders Planman (1724 – 25 April 1803) was a Finnish astronomer, professor of physics and mathematician. He was one of the first people to make systematical astronomical observations in Finland. Planman came from a Swedish-speaking Finnish family and his father was a lieutenant. He studied at the
Stephen Alexander (astronomer) Stephen Alexander (astronomer) Stephen Alexander (September 1, 1806 – June 25, 1883) was a noted astronomer and educator. He was born in Schenectady, New York. He was the brother-in-law of Joseph Henry, the first secretary of the Smithsonian, and worked closely with him. He graduated from Union College in 1824. He became a tutor in mathematics at Princeton University in 1832; he would later become professor of astronomy and mathematics and advocate for the construction of Princeton's first observatory. Alexander relied on the assistance of a free African American man named Alfred Scudder, who worked for him at Princeton during