Who found the Horsehead Nebula?

Answer 1

The Horsehead Nebula was discovered by Mrs. Williamina Fleming on Harvard College Observatory Bache Telescope plate B2312, noted by Professor E. C. Pickering in his Harvard Annals publication of new objects discovered by Photography at Harvard in Cambridge, Massachusetts, published in 1890. The discovery was made by her on June 27, 1888, and the plate was exposed on February 6, 1888. It was Mrs. Fleming's job to examine and analyze the photographs for details and possible new objects. Professor Pickering also reported that his brother, William, had immediately speculated that the nebula consisted of dark, obscuring matter: and thus from the very beginning, the correct scientific nature of the phenomenon was comprehended.

However, though the large bright nebula IC-434, upon which the Horsehead is superimposed on Earth's line of sight, was catalogued in 1895 (with a mistaken attribution to "Pickering", not Fleming), the Horsehead itself was not generally acknowledged in astronomical catalogues for some years, until Edward E. Barnard included it as his item no. 33 in a paper containing a list of 182 dark 'markings', published in 1919. Though others photographed the Horsehead after 1891, Barnard was apparently the first person to observe and study it visually, in 1913.

Stephen Waldee, a California amateur astronomer and researcher, turned up the forgotten and unacknowledged facts in the old Harvard publication and -- with the cooperation of Martha Hazen, Curator of Harvard's Historical Photographs -- the original plate, during a research project in 1989/90. The saga of Mrs. Fleming's work on the nebula and other such objects discovered in Harvard's early photographic program was chronicled and published over the next few years, in a joint Waldee-Hazen paper, a magazine article, and eventually a large research website. Mrs. Fleming's work was finally professionally recognized (unfortunately not her Horsehead discovery!) in 1908, with the publication of the second Index Catalogue; she found no fewer than 59 gaseous nebulae on various Harvard photographs made in Massachusetts and Arequipa, Peru. In addition she discovered novae and hundreds of variable stars. But her seminal discovery of the Horsehead was not understood prior to the Waldee-Hazen paper of 1990. -- Stephen R. Waldee

Answer 2

The Horsehead Nebula was first recorded by Scottish astronomer Williamina Fleming in 1888 at the Harvard College Observatory. However, it was later identified and popularized by astronomer Edward Emerson Barnard in 1913.