The history of the discovery of M42

While visible as nebulous patch to the naked eye even under moderate conditions, the Orion Nebula seems to have escaped pre-telescopic detection; only the bright star Theta1 Orionis, which is situated within the nebula, was wellknown to ancient and medevial astronomers. Even Galilei didn't mention it, although he detected a number of stars around it during his first telescopic observations in 1610.

A considerable number of consequent independent discoveries of this nebula followed the invention of telescope:

Nicholas-Claude Fabri de Peiresc, a French lawyer, found it first, on November 26, 1610, with his telescope. See his discovery observations.
Jesuit astronomer J.-B. Cysatus of Lucerne (1588-1657) rediscovered it in 1611, published in 1619 in his Mathemata astronomica de cometa anni 1618.
Giovanni Batista Hodierna discovered it somewhen before 1654, and created the first preserved drawing, or sketch, of the nebula; he also discovered three of the Trapezium cluster stars.

All these discoveries didn't get publicly known, but were forgotten for a considerable period of time. Consequently, the independent rediscovery by Christiaan Huygens of 1656 was longly considered original, e.g. by De Cheseaux and Messier.

It was not before 1854 when R. Wolf found and published Cysatus' discovery (Astr. Nachrichten, Vol. 38, No. 859, col. 109). M.G. Bigourdan recovered Peiresc's original discovery in 1916 (Comptes Rendus, Vol. 162, p. 64; also referring to Cysatus' finding), while Hodierna's work was rediscovered only in the 1980s.

Hartmut Frommert (spider@seds.org)
Christine Kronberg (smil@lrz.uni-muenchen.de)

Last Modification: 26 Jun 2001, 00:40 MET