The Dumbbell Nebula

Degree of difficulty 2 (of 5)

Minimum aperture 30mm

Designation NGC 6853

Type Planetary nebula

Class III+II

Distance 1150 ly (2004) 1350 ly (1999)

Size 3 ly

Constellation Vulpecula

R.A. 19h 59.6min

Decl. +22° 43′

Magnitude 7.4

Surface brightness –

Apparent diameter 8.4′×6.1′

Discoverer Messier, 1764

History The discovery of M 27 by Charles Messier on the 12th of July 1764, was the first discovery of a planetary nebula. He described his find with the words: “Nebula without star; it is well seen with a simple refractor of 3½ feet; it appears in an oval shape & does not contain any star, 4′ diameter.”

William Herschel was the first to recognize the peculiar dumbbell shape but believed it was a “double stratum of stars of a very great extent, one end of which is facing us.” Later, his son John gave the nebula its now popular name: “a nebula shaped like a dumbbell.” He continues his description: “with the elliptic outline completed by a feeble nebulous light. Position of the axis of symmetry through the centers of the two chief masses 30° to 60°. The diameter of the elliptic light fills a space nearly equal to that between the wires (7′ or 8′). Not resolvable, but I see on it four distinct stars: 1 st 12th magnitude at the south following edge; 2nd 12th magnitude to 13th magnitude, almost diametrically opposite; 3 rd 13th magnitude in the north preceding quarter, and 4th 14th to 15th magnitude near the center.” In a later description, John Herschel called M 27 “shaped something like an hourglass, filled into an oval outline with a much less dense nebulosity. The central mass may be compared to a vertebra or a dumb-bell. The southern head is denser than the northern.”