Born Birmingham, England, 28 May 1858

Died Tow Law, Durham, England, 2 December 1934

Using 17- and 24-in. reflecting telescopes, the Reverend Thomas Espin discovered and measured 2,575 double stars and prepared catalogs of 3,800 red stars classified on the basis of his spectroscopic examination. As the son of Reverend Thomas Espinell and Elizabeth (née Jessop) Espin, he enjoyed a privileged childhood, was educated at Oxford, and entered the ministry of the Church of England. In 1888, at 33 years of age, he became Vicar of Tow Law, a position he held as a single clergyman for the remainder of his life. His scientific interests were broad, in common with many clergymen of his time, but his strongest interest was astronomy.

The appearance of comet C/1874 H1 (Coggia) in April 1874 stimulated Espin’s earliest efforts in observational astronomy. It was not long after the event that he began contributing regular articles, signed T.E.E., to The English Mechanic, a practice he continued for most of his active career. At about the same time, the Prebendary   Thomas Webb solicited Espin’s help in gathering and editing information for a revision of Webb’s Celestial Objects for Common Telescopes, an honor for the young observer. Espin continued to work with Celestial Objects after Webb’s death, and eventually published a reedited and enlarged two-volume fifth edition (1893; reprinted 1905) of Webb’s original book, which by then had become a standard work for amateur astronomers. In 1917 Espin updated a sixth edition of Celestial Objects.

Espin examined the stars listed in the Bonner Durchmustrung (Bonn survey) with a spectroscope of his own design using his large telescopes. With this approach it was possible to more reliably detect those stars with redder than normal colors. Espin gathered observations for a total of 3,800 red stars into several catalogs following the earlier examples of   Thomas Backhouse and   John Birmingham . In 1890, having carefully verified the colors given by others and after adding his own discoveries, Espin published the results as a sixth edition of Birmingham’s catalog of red stars. The stars included in Espin’s catalogs were generally too faint to appear in the Harvard catalogs of spectra, which added to the value of his work. Espin also recognized that many of the red stars he was cataloguing were variable; he is credited with the discovery of more than 30 new variable stars. The most noteworthy of his variable star discoveries was Nova Lacertae, discovered in 1910. In his extensive survey, Espin measured and recorded the positions of 2,575 pairs of close stars.

With Webb as a mentor, a solid observing program, and an aggressive effort to publish his results in the English Mechanic, it should be no surprise that Espin was well known as an amateur astronomer. He was an active participant in several efforts to organize amateur astronomers in England. When the Liverpool Astronomical Society [LAS] was formed in 1881, Espin became an active member, along with   Isaac Roberts ,   William Denning , Webb,   Thomas Elger , and other well-known amateurs from the region. Espin was the second LAS president (1884/1885). When the LAS leadership recognized that overly enthusiastic members were reporting spurious observations as “discoveries,” Espin volunteered to make confirming observations on short notice. However, his efforts led to conflicts over his methods of making attributions of the discovery priority and to other problems. When LAS ultimately failed, Espin became an active member of the British Astronomical Association.

Espin was a fellow of the Royal Astronomical Society. In 1913, he received its Jackson-Gwilt Medal for his discoveries of double stars and catalog of red stars as well as his Nova Lacertae discovery. He was elected to the International Astronomical Union Commission on Double Stars.