Likened to
a stellar womb, the iconic soaring space towers known as the Pillars
of Creation have revealed an embryo of an infant star that could develop
into a twin of our Sun.
Astronomers
imaged the baby
star in what they consider the earliest stages of development ever detected
for this type of object.
Hiding out
on a nodule that juts out from the left pillar, "E42" is known as an evaporating
gas globule (EGG). An EGG is a dense pocket of interstellar gas that forms an
"egg" from which a star emerges. This particular EGG has the same mass as the Sun
and appears to be maturing in a violent environment matching the one thought to
have produced Earth's life-giving star.
"We think
this is a very, very early version of our own Sun," said Jeffrey Linsky of
JILA, a joint institute of the University of Colorado, Boulder and the National
Institute of Standards and Technology.
Star
factory
Linsky and
his colleagues used NASA's Chandra
X-ray Observatory to peek at the embryo inhabiting the Eagle
Nebula.
Located
about 7,000 light-years from Earth,
the Eagle Nebula is a star-forming region within the Pillars of Creation where
nearby gas and dust feed the birth of new stars. Many of the stars churned out
here now reside just outside the pillars, where their ultraviolet emissions
sculpt out the structures.
The newbie
is one of 73 EGGs discovered in this celestial
castle in 1995 with the Hubble Space Telescope
(HST). While 11 of the gas globules are thought to contain infant stellar
objects, only four are massive enough to form a star. Of those, E42 is the only
one that boasts a Sun-sized mass.
"The four
proto-stars that we have identified on the edges of the pillars are probably
the youngest stars ever imaged by astronomers," Linsky said.
While the
X-ray capability let the team view about 1,100 hot, mature
stars in the nebula, the EGGs
were not emitting any X-rays due to their infantile
natures.
Instead the
scientists viewed visual and infrared emissions to pinpoint E42 [image]
and its neighbors.
"The
results indicate young, evolving stars like E42 have not yet developed the
magnetic structures needed to produce X-rays," he said.
Brutal
birth
In addition
to its mass, E42 is maturing in an environment similar to what astronomers
think produced Earth's
Sun, 5 billion years ago. Unlike a nurturing womb, however, Earth's Sun seemed to form from clouds of dust and
gas that got seared by ultraviolet radiation and pummeled with shock waves from
at least one supernova
explosion.
"The Sun
was likely born in a region like the Pillars of Creation because the chemical
abundances in the solar system indicate that a supernova occurred nearby and
contributed its heavy elements to the gas of which the Sun and the planets
formed," Linsky explained.
In January
2007, a French astronomy team observed a glowing cloud of scorched dust next to
the pillars, suggesting that about 6,000 years ago a supernova explosion toppled
the stellar structures. The newly described proto-star E42 apparently
emerged unscathed.
"My guess is
that the shock wave from the supernova may have been far enough away so that
E42 and some of the other stars may have survived," said Linsky. "But I guess
we will have to wait another thousand years or so to get the answer."
The study
is published in the Jan. 1 issue of the Astrophysical Journal.
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