Chuck Bednar for redOrbit.com – Your Universe Online
In honor of its upcoming 25th anniversary, NASA’s Hubble Space Telescope has revisited the site where it captured one of its most iconic images, the three giant columns of cold gas known as the “Pillars of Creation.”
Hubble originally photographed the butte-like structures in 1995, revealing previously unseen details of the gas columns that were bathed in ultraviolet light from a nearby cluster of massive young stars a region of the Eagle Nebula (M16).
According to the Space Telescope Science Institute, the original image of the “Pillars of Creation” went on to become so popular that it appeared in movies and television shows, as well as on t-shirts, pillows and even postage stamps. Now, as it prepares to mark its silver anniversary of service, Hubble as returned to the scene to capture even better images of the location.
The new images are sharper and wider, the Institute says, and have pillars have been photographed in both visible light and near-infrared light. The infrared view makes the pillars appear as “eerie, wispy silhouettes seen against a background of myriad stars,” because it penetrates all but the densest regions of gas and dust surrounding the pillars.
The new images are being officially unveiled at this year’s annual meeting of the American Astronomical Society (AAS), taking place this week at the Washington State Convention Center in Seattle, and reveals newborn stars hidden amongst the pillars.
“I’m impressed by how transitory these structures are,” said Paul Scowen of Arizona State University, who was one of the leaders of the original Hubble observations at the Eagle Nebula. “They are actively being ablated away before our very eyes. The ghostly bluish haze around the dense edges of the pillars is material getting heated up and evaporating away into space.”
“We have caught these pillars at a very unique and short-lived moment in their evolution,” he added. The infrared image indicates that the reasons that the pillars exist is because the ends of them are dense, shadowing the gas below them and creating the long, column-like structures.
The gas located in between the pillars was blown away long ago by ionizing winds from the central star cluster located above the pillars, the Institute explained. At the top edge of the left pillar, a gaseous fragment has been heated up and is flying away from the structure. The finding underscores the “violent nature of star-forming regions,” they added.
“These pillars represent a very dynamic, active process,” said Scowen. “The gas is not being passively heated up and gently wafting away into space. The gaseous pillars are actually getting ionized (a process by which electrons are stripped off of atoms) and heated up by radiation from the massive stars. And then they are being eroded by the stars’ strong winds (barrage of charged particles), which are sandblasting away the tops of these pillars.”
When he and ASU colleagues Jeff Hester used Hubble to make the initial observations of the Eagle Nebula in 1995, the pillars had only been seen in ground-based images lacking the detail of those captured by the telescope. While the processes that take place are not unique to the nebula, at a distance of 6,500 light-years, it is the closest, most dramatic area of such activity.
Scowen recalled that he and Hester were amazed by the detail of the pictures, which allowed them to see features of the pillars for the first time. Among the first things that jumped out to them in 1995 were the streamers of gas floating away from the columns, which helped settle a debate about what impact nearby massive stars would have on gas in stellar nurseries.
“There is only one thing that can light up a neighborhood like this: massive stars kicking out enough horsepower in ultraviolet light to ionize the gas clouds and make them glow,” he explained. “Nebulous star-forming regions like M16 are the interstellar neon signs that say, ‘We just made a bunch of massive stars here.’ This was the first time we had directly seen observational evidence that the erosionary process, not only the radiation but the mechanical stripping away of the gas from the columns, was actually being seen.”
A comparison of the 1995 and 2014 images allowed researchers to notice that a narrow jet-like feature that may have been ejected from a newly forming star was been growing longer. This jet, which resembles a stream of water coming from a garden hose, has expanded to cover an additional 60 billion miles and is travelling at speeds of roughly 450,000 miles per hour.
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