The Engraved Hourglass Nebula (also known as MyCn 18) is a young planetary nebula situated in the southern constellation Musca about 8,000 light-years away from Earth. It was discovered by Annie Jump Cannon and Margaret W. Mayall during their work on an extended Henry Draper Catalogue. At the time it was designated simply as a small faint planetary nebula. Much improved telescopes and imaging techniques allowed the hourglass shape of the nebula to be discovered by Raghvendra Sahai and John Trauger of the Jet Propulsion Laboratory on July 30, 1995. It is conjectured that MyCn 18's hourglass shape is produced by the expansion of a fast stellar wind within a slowly expanding cloud which is denser near its equator than its poles.
The Hourglass Nebula was photographed by the Wide Field and Planetary Camera 2 of the Hubble Space Telescope.
It should be noted there is another nebula which shares the designation of hourglass nebula it can be found in the Lagoon Nebula.
It should be noted there is another nebula which shares the designation of hourglass nebula it can be found in the Lagoon Nebula.
Observation data
Right ascension: 13h 39m 35.116s
Declination: -67° 22′ 51.45″
Distance: 8 kly (2.5 kpc)
Apparent magnitude: 13.0
Constellation: Musca
Declination: -67° 22′ 51.45″
Distance: 8 kly (2.5 kpc)
Apparent magnitude: 13.0
Constellation: Musca
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