Comet-like star streaks through Milky Way
Pastor Dale Morgan
Comet-like star streaks through Milky Way*
* Story Highlights
* A dying star is leaving a turbulent tail of oxygen, carbon and
nitrogen in its wake
* Images show the tail as a glowing light-blue stream
* The star, Mira, is a so-called "red giant" star near the end of
its life
WASHINGTON (Reuters) -- A large star in its death throes is leaving a
huge, turbulent tail of oxygen, carbon and nitrogen in its wake that
makes it look like an immense comet hurtling through space, astronomers
said on Wednesday.
This dying star is shedding material that will be recycled into new
stars, planets and possibly even life.
Nothing like this has ever previously been witnessed in a star,
according to scientists who detected it using NASA's Galaxy Evolution
Explorer, an orbiting space telescope that observes the cosmos in
ultraviolet light.
This tail, spanning a stunning distance of 13 light-years, was detected
behind the star Mira, located 350 light-years from Earth in the "whale"
constellation Cetus.
"There's a star with a tail in the tail of the whale," said one of the
researchers, astronomer Mark Seibert of the Observatories of the
Carnegie Institution of Washington in Pasadena, California.
A light year is about 6 trillion miles, the distance light travels in a
year.
Rocketing through our Milky Way galaxy at 80 miles per second --
literally faster than a speeding bullet -- the star is spewing material
that scientists believe may be recycled into new stars, planets and
maybe even life.
"We believe that the tail is made up of material that is being shed by
the star which is heating up and then spiraling back into this turbulent
wake," said astronomer Christopher Martin of California Institute of
Technology, one of the researchers in the study published in the journal
Nature.
Mira is a so-called "red giant" star near the end of its life.
Astronomers believe our sun will become a similar red giant in 4 to 5
billion years, but they doubt it will develop such a tail because it is
not moving through space as quickly.
"It's giving us this fantastic insight into the death processes of stars
and their renewals -- their phoenix-like revivals as their ashes get
cycled backed into the next generation of stars," added Michael Shara of
the American Museum of Natural History and Columbia University in New York.
Shara said he expects that as this telescope continues mapping the
cosmos in ultraviolet light for the first time, other similar stars may
be discovered. "There must be lots more of these things," Shara said.
NASA images show the tail as a glowing light-blue stream of material
including oxygen, carbon and nitrogen.
This material has been blown off Mira gradually over time -- the oldest
was released roughly 30,000 years ago as part of a long stellar death
process -- and is enough to form at least 3,000 future Earth-sized
planets, the scientists said.
The astronomers were surprised to find this unique feature in Mira, a
well-known star studied since the 16th century. Mira stems from the
Latin word for "wonderful."
Despite having about the same mass as the sun, Mira has swollen up to
over 400 times the size of the sun, meaning the force of gravity is
having a hard time holding it together, Seibert said.
The tail stretching 13 light-years is thousands of times the length of
our solar system. The nearest star to Earth, called Proxima Centauri, is
located 4 light-years away.
While this star looks like a comet, stars and comets are quite different
celestial bodies. Comets in our solar system are relatively small
objects made up of rock, dust and ice trailed by a tail of gas and dust.
Unlike our solitary sun, Mira is a so-called binary star traveling
through space orbiting a companion believed to be the burnt-out, dead
core of a star, known as a white dwarf.
Scientists think Mira in time will eject all its gas, leaving a colorful
shell known as a planetary nebula that also gradually will fade leaving
behind a white dwarf.