Famous space pillars feel the heat of star's explosion
Tue Jan 9, 2007 at 20:39 UTC
The three iconic space pillars photographed by Hubble Space Telescope in 1995 might have met their demise, according to new evidence from NASA's Spitzer Space Telescope.
A new, striking image from Spitzer shows the intact dust towers next to a giant cloud of hot dust thought to have been scorched by the blast of a star that exploded, or went supernova. Astronomers speculate that the supernova's shock wave could have already reached the dusty towers, causing them to topple about 6,000 years ago. However, because light from this region takes 7,000 years to reach Earth, we won't be able to capture photos of the destruction for another 1,000 years or so.
Spitzer's view of the region shows the entire Eagle nebula, a vast and stormy community of stars set amid clouds and steep pillars made of gas and dust, including the three well-known "Pillars of Creation."
"I remember seeing a photograph of these pillars more than a decade ago and being inspired to become an astronomer," said Nicolas Flagey of The Institut d'Astrophysique Spatiale in France. "Now, we have discovered something new about this region we thought we understood so well." Flagey, a visiting graduate student at NASA's Spitzer Science Center at the California Institute of Technology in Pasadena, presented the results today at the American Astronomical Society meeting in Seattle.
Astronomers have long predicted that a supernova blast wave would mean the end for the popular pillars. The region is littered with 20 or so stars ripe for exploding, so it was only a matter of time, they reasoned, before one would blow up. The new Spitzer observations suggest one of these stellar time bombs has in fact already detonated, an event humans most likely witnessed 1,000 to 2,000 years ago as an unusually bright star in the sky.
Whenever the mighty pillars do crumble, gas and dust will be blown away, exposing newborn stars that were forming inside. A new generation of stars might also spring up from the dusty wreckage.
Image Credit: NASA/JPL-Caltech/N. Flagey (IAS/SSC) & A. Noriega-Crespo (SSC/Caltech)
High resolution image (5.7 MB)
This majestic view taken by NASA's Spitzer Space Telescope tells an untold story of life and death in the Eagle nebula, an industrious star-making factory located 7,000 light-years away in the Serpens constellation. The image shows the region's entire network of turbulent clouds and newborn stars in infrared light.
The color green denotes cooler towers and fields of dust, including the three famous space pillars, dubbed the "Pillars of Creation," which were photographed by NASA's Hubble Space Telescope in 1995 (see inset).
But it is the color red that speaks of the drama taking place in this region. Red represents hotter dust thought to have been warmed by the explosion of a massive star about 8,000 to 9,000 years ago. Since light from the Eagle nebula takes 7,000 years to reach us, this "supernova" explosion would have appeared as an oddly bright star in our skies about 1,000 to 2,000 years ago.
According to astronomers' estimations, the explosion's blast wave would have spread outward and toppled the three pillars about 6,000 years ago (which means we wouldn't witness the destruction for another 1,000 years or so). The blast wave would have crumbled the mighty towers, exposing newborn stars that were buried inside, and triggering the birth of new ones.
The pillars of the Eagle nebula were originally sculpted by radiation and wind from about 20 or so massive stars hidden from view in the upper left portion of the image. The radiation and wind blew dust away, carving out a hollow cavity (center) and leaving only the densest nuggets of dust and gas (tops of pillars) flanked by columns of lighter dust that lie in shadow (base of pillars). This sculpting process led to the creation of a second generation of stars inside the pillars.
If a star did blow up in this region, it is probably located among the other massive stars in the upper left portion of the image. Its blast wave might have already caused a third generation of stars to spring from the wreckage of the busted pillars.
This image is a composite of infrared light detected by Spitzer's infrared array camera and multiband imaging photometer. Blue is 4.5-micron light; green is 8-micron light; and red is 24-micron light.
Image Credit:
High resolution image (3.8 MB)
This set of images from NASA's Spitzer Space Telescope shows the Eagle nebula in different hues of infrared light. Each view tells a different tale. The left picture shows lots of stars and dusty structures with clarity. Dusty molecules found on Earth called polycyclic aromatic hydrocarbons produce most of the red; gas is green and stars are blue.
The middle view is packed with drama, because it tells astronomers that a star in this region violently erupted, or went supernova, heating surrounding dust (orange). This view also reveals that the hot dust is shell shaped, another indication that a star exploded.
The final picture highlights the contrast between the hot, supernova-heated dust (green) and the cooler dust making up the region's dusty star-forming clouds and towers (red, blue and purple).
The left image is a composite of infrared light with the following wavelengths: 3.6 microns (blue); 4.5 microns (green); 5.8 microns (orange); and 8 microns (red). The right image includes longer infrared wavelengths, and is a composite of light of 4.5 to 8.0 microns (blue); 24 microns (green); and 70 microns (red). The middle image is made up solely of 24-micron light.
Image Credit: NASA/JPL-Caltech/N. Flagey (IAS/SSC) & A. Noriega-Crespo (SSC/Caltech
High resolution image (4.1 MB)
This image composite highlights the pillars of the Eagle nebula, as seen in infrared light by NASA's Spitzer Space Telescope (bottom) and visible light by NASA's Hubble Space Telescope (top insets).
The top right inset focuses on the three famous pillars, dubbed the "Pillars of Creation," which were photographed by Hubble in 1995. Hubble's optical view shows the dusty towers in exquisite detail, while Spitzer's infrared eyes penetrate through the thick dust, revealing ghostly transparent structures. The same effect can be seen for the pillar outlined in the top left box.
In both cases, Spitzer's view exposes newborn stars that were hidden inside the cocoon-like pillars, invisible to Hubble. These stars were first uncovered by the European Space Agency's Infrared Satellite Observatory. In the Spitzer image, two embedded stars are visible at the tip and the base of the left pillar, while one star can be seen at the tip of the tallest pillar on the right.
Spitzer is a space telescope that detects infrared, longer-wavelength light that our eyes cannot see. This allows the observatory to both see the dust and see through it, depending on which infrared wavelength is being observed. In Spitzer's new look at the Eagle nebula, the three pillars appear small and ghostly transparent. They are colored green in this particular view. In the largest of the three columns, an embedded star is seen forming inside the tip.
Above the pillars is the enormous cloud of hot dust, colored red in the picture, which astronomers think was seared by the blast wave of a supernova explosion. Flagey and his team say evidence for this scenario comes from similarities observed between this hot dust and dust around known supernova remnants. The dust also appears to have a shell-like shape, implying that a supernova blast wave is traveling outward and sculpting it.
The mysterious dust was first revealed in previous images from the European Space Agency's Infrared Space Observatory, but Spitzer's longer-wavelength infrared instrument was able to tentatively match the dust to a supernova event.
"Something else besides starlight is heating this dust," said Dr. Alberto Noriega-Crespo, Flagey's advisor at the Spitzer Science Center. "With Spitzer, we now have the missing long-wavelength infrared data that are giving us an answer."
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