Hourglass Nebula
Encyclopedia
The Engraved Hourglass Nebula (also known as MyCn 18) is a young planetary nebula
situated in the southern constellation Musca
about 8,000 light-year
s away 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). 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 January 18, 1996. 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
.
A less-famous "Hourglass Nebula" is located inside the Lagoon Nebula
.
Planetary nebula
A planetary nebula is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their life...
situated in the southern constellation Musca
Musca
Musca is one of the minor southern constellations. The constellation was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm diameter celestial globe published in 1597 in Amsterdam by...
about 8,000 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. It was discovered by Annie Jump Cannon
Annie Jump Cannon
Annie Jump Cannon was an American astronomer whose cataloging work was instrumental in the development of contemporary stellar classification. With Edward C...
and Margaret W. Mayall during their work on an extended Henry Draper Catalogue
Henry Draper Catalogue
The Henry Draper Catalogue is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension , published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the...
(the catalogue was built between 1918 and 1924). 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
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
on January 18, 1996. It is conjectured that MyCn 18's hourglass
Hourglass
An hourglass measures the passage of a few minutes or an hour of time. It has two connected vertical glass bulbs allowing a regulated trickle of material from the top to the bottom. Once the top bulb is empty, it can be inverted to begin timing again. The name hourglass comes from historically...
shape is produced by the expansion of a fast stellar wind
Stellar wind
A stellar wind is a flow of neutral or charged gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric.Different types of stars have...
within a slowly expanding cloud
Cloud
A cloud is a visible mass of liquid droplets or frozen crystals made of water and/or various chemicals suspended in the atmosphere above the surface of a planetary body. They are also known as aerosols. Clouds in Earth's atmosphere are studied in the cloud physics branch of meteorology...
which is denser near its equator than its poles.
The Hourglass Nebula was photographed by the Wide Field and Planetary Camera 2
Wide Field and Planetary Camera 2
The Wide Field and Planetary Camera 2 is a baby grand piano sized camera built by the Jet Propulsion Laboratory and formerly installed on the Hubble Space Telescope. It was installed by servicing mission 1 in 1993, replacing the telescope's original Wide Field and Planetary Camera...
of the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
.
A less-famous "Hourglass Nebula" is located inside the Lagoon Nebula
Lagoon Nebula
The Lagoon Nebula is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region....
.
Hourglass Nebula in popular culture
- The Hourglass Nebula was featured on the cover of the April 1997 issue of National Geographic. The nebula’s unique appearance led the magazine’s editors to comment, “Astronomers looked 8,000 light-years into the cosmos with the Hubble Space Telescope, and it seemed that the eye of God was staring back.”
- The Hourglass Nebula also serves as the front cover for Pearl JamPearl JamPearl Jam is an American rock band that formed in Seattle, Washington, in 1990. Since its inception, the band's line-up has included Eddie Vedder , Jeff Ament , Stone Gossard , and Mike McCready...
's 2000 album BinauralBinaural (album)Binaural is the sixth studio album by the American alternative rock band Pearl Jam, released on May 16, 2000 through Epic Records. Following a full-scale tour in support of its previous album, Yield , Pearl Jam took a short break before reconvening toward the end of 1999 to commence work on a new...
. - The Hourglass Nebula appears in the popular game, Final DoomFinal DoomFinal Doom is a first-person shooter video game that uses the game engine, items and characters from Doom II. It consists of two 32-level megawads , The Plutonia Experiment by the Casali brothers, and TNT: Evilution by TeamTNT. Final Doom was released in 1996 and distributed as an official id...
. - The Hourglass Nebula appears on a poster in the CERNCERNThe European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
laboratory in the film Angels & Demons. - The Hourglass Nebula appears extensively, and is used as a major plot point in the 2002 animated series Space Pirate Captain Herlock: The Endless OdysseySpace Pirate Captain Herlock: The Endless OdysseySpace Pirate Captain Herlock: The Endless Odyssey is an OVA sequel to Space Pirate Captain Harlock.-Cast:*Lex Lang as Captain Herlock*Anthony Mozdy as Dr...
. - The Hourglass Nebula appears in the video game titled Mass Effect 2Mass Effect 2Mass Effect 2 is an action role-playing game developed by BioWare and published by Electronic Arts for Microsoft Windows, Xbox 360 and PlayStation 3. The game was released for Microsoft Windows and Xbox 360 on January 26, 2010 and for PlayStation 3 on January 18, 2011...
as one of the clusters that can be visited for missions. - The Hourglass Effect is a 2008 album by the British band ShadowkeepShadowkeepShadowkeep is a British heavy metal band, formed in Guildford, England, in 1999 by guitarists Chris Allen and Nikki Robson .-Early recordings, concerts and festival appearances:...
.