The nebula designated NGC 6751 (as well as NGC 6748 - sic!), colloquially known as the Glowing Eye Nebula, is an object located in the constellation of the Eagle. Discovered on July 20, 1863, by Albert Marth, it was designated NGC 6751 in the New General Catalogue. John Louis Emil Dreyer, compiling observational data for the New General Catalogue, described the object as "quite bright, small." Several years later, on July 17, 1871, it was also observed by Édouard Stephan, who mistakenly identified a reference star, resulting in an incorrect position and the belief that a new object had been discovered. This observation was cataloged as NGC 6748. Due to this error, NGC 6748 was considered "lost" for many years.

NGC 6751, like all planetary nebulae, formed when a dying star expelled its outer layers of gas, creating a beautiful, characteristic envelope. This nebula is located about 6500 light-years away from us (2 kiloparsecs). It spans about 0.8 light-years, with the dimensions of its bright core estimated at 24 x 27 arcseconds. The nebula has a total brightness of 15.48 mag, which, given its very compact structure, gives it a rather high surface brightness.

The nebula has a complex bipolar structure, which has been captured quite well in the part of the photograph I took using Lucky Imaging technique. Clearly visible are the bright inner bubble and two fainter shells. Along the axis of this nebula's poles, two hydrogen emission knots can also be observed. Classic photography techniques have managed to capture the outer structures, including the fairly characteristic "lobe" with a high concentration of hydrogen and oxygen, as well as typical oxygen-rich "halos." In spectral analysis, one can observe the usual emission lines for planetary nebulae - H-alpha and OIII, as well as HeI, HeII, and weak SII. At the center of the NGC 6751 nebula lies the hot central star HD 177656 with a temperature of about 140,000 K and a spectral characteristic similar to Wolf-Rayet stars.