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The Engraved Hourglass Nebula (also known as MyCn 18) is a young planetary nebula in the southern constellation Musca about 8,000 light-years from Earth. It was discovered by Annie Jump Cannon and Margaret W. Mayall during their work on an extended Henry Draper Catalogue (the catalogue was built between 1918 and 1924).
The nebula disk has an angular size of 1.5 Ã 1 arcminutes, making it too small to be resolved with 10Ã50 binoculars. It is best observed using a telescope with an aperture of at least 20 cm (8 in), but even a 7.5 cm (3 in) telescope will reveal its elliptical ring shape.