History

In the late 1950-ies the American astronomer Stewart Sharpless discovered the large nebula Sh 2-129 on the 48 inch Schmidt telescope photo plates of the «Palomar Observatory Sky Survey». In 1959 he published his discovery together with 313 H-II regions in a catalogue. He classified it as of irregular shape with 140 arc minutes diameter some amorphous to filamentary structure with intermediate brightness and noted «Part of I Cep association.» ^[310] The nebula later became known as «Flying Bat Nebula».

In May 2011 the French amateur astrophotographer Nicolas Outters decided to take a picture of Sh 2-129. He took several pictures, each with 30 minutes exposure in May and June using his FSQ-106 refractor and SBIG 6303e CCD camera and Hα, [S II] and [O III] filters, total 12.5 hours. After combining the images taken through the O-III filter he discovered a large structure that seemed to have no coherence with the nebula Sh 2-129. He called it «Le Calamar». The rare pictures of Sh 2-129 on the net he found did not show such a structure. He contacted the French astrophysicist Agnès Acker which did precise studies of this strange object and confirmed an important presence of Oxygen III. The nebula was given the designation Ou4, for the fourth nebula discovered by Outters. ^{[508, 509]}