Hubble: Pillars of Creation are also Pillars of Destruction
 
Jan. 7, 2015:   Although NASA's Hubble Space Telescope has taken many
breathtaking images of the universe, one snapshot stands out from the rest:
the iconic view of the so-called "Pillars of Creation." The
jaw-dropping photo, taken in 1995, revealed never-before-seen details of
three giant columns of cold gas bathed in the scorching ultraviolet light
from a cluster of young, massive stars in a small region of the Eagle
Nebula, or M16.
 
In celebration of its upcoming 25th anniversary in April, Hubble has
revisited the famous pillars, providing astronomers with a sharper and
wider view.  Although the original image was dubbed the Pillars of
Creation, the new image hints that they are also "pillars of
destruction."
 
http://www.nasa.gov/sites/default/files/p1501ay.jpg
 
Astronomers using NASA's Hubble Space Telescope have assembled a bigger and
sharper photograph of the iconic Eagle Nebula's "Pillars of
Creation". Credit: NASA/ESA/Hubble Heritage Team (STScI/AURA)/J.
Hester, P. Scowen (Arizona State U.)
 
"I'm impressed by how transitory these structures are," explains
Paul Scowen of Arizona State University in Tempe. "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." Scowen and astronomer Jeff
Hester, formerly of Arizona State University, led the original Hubble
observations of the Eagle Nebula.
 
The original 1995 images were taken in visible light.  The new image
includes near-infrared light as well. The infrared view transforms the
pillars into eerie, wispy silhouettes seen against a background of myriad
stars. That's because the infrared light penetrates much of the gas and
dust, except for the densest regions of the pillars. Newborn stars can be
seen hidden away inside the pillars.
 
The infrared image shows that the very ends of the pillars are dense knots
of dust and gas. They shadow the gas below them, keeping the gas cool and
creating the long, column-like structures. The material in between the
pillars has long since been evaporated away by the ionizing radiation from
the central star cluster located above the pillars.
 
At the top edge of the left-hand pillar, a gaseous fragment has been heated
up and is flying away from the structure, underscoring the violent nature
of star-forming regions. "These pillars represent a very dynamic,
active process," Scowen said. "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 and barrage of charged particles,
which are literally sandblasting away the tops of these pillars."
 
When Scowen and Hester used Hubble to make the initial observations of the
Eagle Nebula in 1995, astronomers had seen the pillar-like structures in
ground-based images, but not in detail. They knew that the physical
processes are not unique to the Eagle Nebula because star birth takes place
across the universe. But at a distance of just 6,500 light-years, M16 is
the most dramatic nearby example - as the team soon realized.
 
[Same as JPG above]
 
The original 1995 image was beautiful. Compare this view to the 2014 image
in a side-by-side montage
 
As Scowen was piecing together the Hubble exposures of the Eagle, he was
amazed at what he saw. "I called Jeff Hester on his phone and said,
`You need to get here now,'" Scowen recalled. "We laid the
pictures out on the table, and we were just gushing because of all the
incredible detail that we were seeing for the very first time."
 
The first features that jumped out at the team in 1995 were the streamers
of gas seemingly floating away from the columns. Astronomers had previously
debated what effect nearby massive stars would have on the surrounding gas
in stellar nurseries. "There is the 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," Scowen
said. "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."
 
By comparing the 1995 and 2014 pictures, astronomers also noticed a
lengthening of a narrow jet-like feature that may have been ejected from a
newly forming star. The jet looks like a stream of water from a garden
hose. Over the intervening 19 years, this jet has stretched farther into
space, across an additional 60 billion miles, at an estimated speed of
about 450,000 miles per hour.
 
Our sun probably formed in a similar turbulent star-forming region. There
is evidence that the forming solar system was seasoned with radioactive
shrapnel from a nearby supernova. That means that our sun was formed as
part of a cluster that included stars massive enough to produce powerful
ionizing radiation, such as is seen in the Eagle Nebula. "That's the
only way the nebula from which the sun was born could have been exposed to
a supernova that quickly, in the short period of time that represents,
because supernovae only come from massive stars, and those stars only live
a few tens of millions of years," Scowen explained. "What that
means is when you look at the environment of the Eagle Nebula or other
star-forming regions, you're looking at exactly the kind of nascent
environment that our sun formed in."
 
Credits:
Production editor: Dr. Tony Phillips | Credit: Science{at}NASA
 
More information:
 
The Hubble Space Telescope is a project of international cooperation
between NASA and the European Space Agency. NASA's Goddard Space Flight
Center in Greenbelt, Maryland, manages the telescope. The Space Telescope
Science Institute (STScI) in Baltimore conducts Hubble science operations.
STScI is operated for NASA by the Association of Universities for Research
in Astronomy, Inc., in Washington.
 
NASA is exploring our solar system and beyond to understand the universe
and our place in it. We seek to unravel the secrets of our universe, its
origins and evolution, and search for life among the stars. Today's
announcement shares the discovery of our ever-changing cosmos, and brings
us closer to learning whether we are alone in the universe.
 
 
Regards,
 
Roger

--- D'Bridge 3.99