[M16]

The November 1995 Hubble shots of M16

Click on the images to get full-size versions [M16, HST full field]

Gas Pillars in the Eagle Nebula M16

Pillars of Creation in a star-forming region

Undersea corral? Enchanted castles? Space serpents? These eerie, dark pillar-like structures are actually columns of cool interstellar hydrogen gas and dust that are also incubators for new stars. The pillars protrude from the interior wall of a dark molecular cloud like stalagmites from the floor of a cavern. They are part of the "Eagle Nebula" M16, a nearby star-forming region 7,000 light-years away in the constellation Serpens.

The pillars are in some ways akin to buttes in the desert, where basalt and other dense rock have protected a region from erosion, while the surrounding landscape has been worn away over millennia. In this celestial case, it is especially dense clouds of molecular hydrogen gas (two atoms of hydrogen in each molecule) and dust that have survived longer than their surroundings in the face of a flood of ultraviolet light from hot, massive newborn stars (off the top edge of the picture). This process is called "photoevaporation". This ultraviolet light is also responsible for illuminating the convoluted surfaces of the columns and the ghostly streamers of gas boiling away from their surfaces, producing the dramatic visual effects that highlight the three-dimensional nature of the clouds. The tallest pillar (left) is about a light-year long from base to tip.

As the pillars themselves are slowly eroded away by the ultraviolet light, small globules of even denser gas buried within the pillars are uncovered. These globules have been dubbed "EGGs." EGGs is an acronym for "Evaporating Gaseous Globules," but it is also a word that describes what these objects are. Forming inside at least some of the EGGs are embryonic stars -- stars that abruptly stop growing when the EGGs are uncovered and they are separated from the larger reservoir of gas from which they were drawing mass. Eventually, the stars themselves emerge from the EGGs as the EGGs themselves succumb to photoevaporation.

The picture was taken on April 1, 1995 with the Hubble Space Telescope Wide Field and Planetary Camera 2. The color image is constructed from three separate images taken in the light of emission from different types of atoms. Red shows emission from singly-ionized sulfur atoms. Green shows emission from hydrogen. Blue shows light emitted by doubly- ionized oxygen atoms.

  • Also available as PNG image and hi-res JPG
  • STScI Press Release PRC95-44a on Geseous Pillars in M16
  • This image was featured as Astronomy Picture of the Day (APOD) November 6, 1995, January 19, 1997, April 12 1998, May 2 1999, and September 24 2000

    [M16, HST WFPC2]

    Star-Birth Clouds in M16

    Stellar "EGGs" emerge from Molecular Clouds

    This eerie, dark structure, resembling an imaginary sea serpent's head, is a column of cool molecular hydrogen gas (two atoms of hydrogen in each molecule) and dust that is an incubator for new stars. The stars are embedded inside finger-like protrusions extending from the top of the nebula. Each "fingertip" is somewhat larger than our own solar system.

    The pillar is slowly eroding away by the ultraviolet light from nearby hot stars, a process called "photoevaporation". As it does, small globules of especially dense gas buried within the cloud is uncovered. These globules have been dubbed "EGGs" -- an acronym for "Evaporating Gaseous Globules". The shadows of the EGGs protect gas behind them, resulting in the finger-like structures at the top of the cloud.

    Forming inside at least some of the EGGs are embryonic stars -- stars that abruptly stop growing when the EGGs are uncovered and they are separated from the larger reservoir of gas from which they were drawing mass. Eventually the stars emerge, as the EGGs themselves succumb to photoevaporation.

  • Also available as PNG image and hi-res JPG
  • STScI Press Release PRC95-44b on Star-Birth Clouds in M16
  • This image was featured as Astronomy Picture of the Day (APOD) November 7, 1995, February 28 1998, April 2 2000, and August 12 2001
  • Featured as Astronomy Image of the Month November 1995 (Las Positas College)

    [M16, HST, details]

    Evaporating globules in M16

    The stellar EGGS are found, appropriately enough, in the "Eagle Nebula".

    These pictures were taken on April 1, 1995 with the Hubble Space Telescope Wide Field and Planetary Camera 2. The color image is constructed from three separate images taken in the light of emission from different types of atoms. Red shows emission from singly-ionized sulfur atoms. Green shows emission from hydrogen. Blue shows light emitted by doubly- ionized oxygen atoms.

  • Also available as PNG image and hi-res JPG
  • STScI Press Release PRC95-44c on Evaporating Globules in M16

    Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA

  • Paul Scowen's Eagle Nebula page
  • Jeff Hester's Eagle Nebula page


    The following mosaic allows you to identify which regions of the Eagle nebula the Hubble telescope has exposed:

    [M16 Mosaic]

    An animation was obtained from the HST images in this page, simulating the approach to the star forming EGGs in the Eagle Nebula.

    References:


  • AAT images of M16
  • Amateur images of M16; more amateur images
  • More images of M16


    Hartmut Frommert
    Christine Kronberg
    [contact]

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    Last Modification: June 18, 1999