[3] The Society instituted the Leonard Medal in 1962, its premier award for outstanding contributions to the science of meteoritics and closely allied fields.

In 1909 he attended the annual meeting of the Astronomical and Astrophysical Society of America, held at the Yerkes Observatory.

Leonard's leadership raised concerns among professional astronomers[2] as not all were in favor of amateur contributions to the profession.

[11] He authored a year-long series of articles titled "Mr. Leonard's Star Colors" in the English Mechanic and World of Science.

He continued his graduate education at the University of California, Berkeley with Armin Leuschner, being awarded his PhD in 1922[12] for his thesis "An Investigation of the Spectra of Visual Double Stars".

Leonard initially focused his university research on double stars, which he studied using the facilities at Mount Wilson Observatory.

[9] (The equipment for astronomy teaching was very poor at that time; but he got access to telescopes on Mt.Wilson and continued to observe stars and planets for some years).

[21] He was honoured by "striking a medal in his name" after his death for the contribution he had made to the development of the Meteoritical Society[14] Leonard was one of the first astronomers to hypothesize the existence of a trans-Neptunian population.

[5] Hockey, Thomas A; Bracher, Katherine (November 20, 2007), The Biographical Encyclopedia of Astronomers, Springer (published 2007), ISBN 978-0-387-31022-0 Leonard, Frederick D. (March 1, 2018).