Edward Charles Pickering (July 19, 1846–February 3, 1919) was an American astronomer and physicist, brother of William Henry Pickering.

Along with Carl Vogel, Pickering discovered the first spectroscopic binary stars. He wrote Elements of Physical Manipulations (2 vol., 1873–76).

Simon Newcomb (March 12, 1835 – July 11, 1909) was a Canadian-American astronomer and mathematician. Though he had little conventional schooling, he made important contributions to timekeeping as well as writing on economics and statistics and authoring a science fiction novel.

At the meeting of 1890-10-07, among the communications read was one from Joseph Morrison, M.A., M.D., Ph.D., F.R.A.S., Assistant at the American Nautical Almanac Office, Washington, U.S.A., desiring the Society to accept a copy of the American Ephemeris and Nautical Almanac for 1890, 1891, and 1892, and of The Almanac for 1893; also of the Report of the Observations of the Total Eclipse of the Sun, 1889. The thanks of the Society were voted to Dr. Morrison, who, it was announced, was a native of Toronto.

Samuel Pierpont Langley (August 22, 1834, Roxbury, Massachusetts – February 27, 1906, Aiken, South Carolina) was an American astronomer, physicist, inventor of the bolometer and pioneer of aviation. He attended Boston Latin School, graduated from English High School of Boston, was an assistant in the Harvard College Observatory, then moved to a job ostensibly as a professor of mathematics at the United States Naval Academy, but actually was sent there to restore the Academy's small observatory.

Daniel Kirkwood (September 27, 1814 - June 11, 1895) was an American astronomer. Born in Harford County, MD, he was graduated in mathematics from the York County Academy in York, PA in 1838. After teaching there for five years, he became Principal of the Lancaster High School in Lancaster, PA, and after another five years he moved on to become Principal of the Pottsville Academy.

Edward Singleton Holden (November 5, 1846 – March 16, 1914) was an American astronomer.

He was born in St. Louis, Missouri in 1846 to Jeremiah and Sarah Holden. From 1862-66, he attended Washington University in St. Louis, where he obtained a B.S. degree. He later trained at West Point in the class of 1870.

George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer.