The Ring Nebula is a planetary nebula in the northern constellation of Lyra.
Such a nebula is formed when a star, during the last stages of its evolution before becoming a white dwarf, expels a vast luminous envelope of ionized gas into the surrounding interstellar space.
This nebula was discovered by the French astronomer Charles Messier while searching for comets in late January 1779 and was first photographed by the Hungarian astronomer Eugene von Gothard in 1886.
This stereoview also reminds to the work of Dr. Max Wolf: Stereoskopbilder vom Sternhimmel.

With the exception of pictures of the sun and moon astronomical photographs always look flat. From the nature of the case this must be so for the distances are so great that we can have no effect of perspective. But by properly combining photographs taken at suitable intervals of time the stereoscope introduces a perspective and gives an apparent solidity that must be charming to everyone who is interested in celestial objects. [Xavier Debeerst]

Unmounted albumen print with good tonality. Despite the obvious signs of use, it is still a fine and rare example of photographic discoveries in astronomy.

ca. 7,7 x 17,6 cm