Biggest star in cosmos about
to die – Astronomers on october 16, 2013 at 5:21 pm
in news PARIS (AFP) – The biggest
known star in the cosmos is in
its death throes and will
eventually explode,
astronomers said on
Wednesday. Using a telescope at the
European Southern Observatory
in Chile, the astronomers said
they had spotted telltale signs
in a star called W26. Located about 16,000 light
years away in the constellation
of Ara, or The Altar, the star
has a diameter 3,000 times
that of the Sun. W26, first observed in 1998, is
a “red supergiant”, a term for a
star that is as big as it is short-
lived. Stars of this kind typically have
lifetimes of less than a few
million years before they
exhaust their nuclear fuel and
explode as supernovae. W26 is becoming unstable and
shedding its outer layers, a key
step in the death process,
according to the paper,
published in the British journal
Monthly Notices of Britain’s Royal Astronomical Society
(RAS). W26 is “the largest known star
in the Universe”, the RAS said
in a press release. The observations suggest “W26
is coming towards the end of
its life and will eventually
explode as a supernova”. W26 is surrounded by a cloud,
or nebula, of glowing hydrogen
gas whose atoms have been
stripped of their electrons. A similar cloud was found
around the remnant of a star
that became a supernova in
1987. “The presence of the nebula,
high stellar luminosity and
spectral variability suggest that
W26 is a highly evolved RSG
[red supergiant] experiencing
extreme levels of mass loss,” says the paper. W26 is located in a star cluster
called Westerlund 1, home to
hundreds of thousands of stars.
It is the most massive stellar
group in our galaxy, the Milky
Way. Observing Westerlund 1 can be
a problem because light from it
is affected by clouds of gas and
dust. But the ionised gas around
W26 is a boost for visibility,
which should make it easier to
monitor what happens next. When a red supergiant sheds
its outer layers, it does so after
enriching the material from
nuclear reactions deep within
the star. The stuff that is spewed out
includes many elements, such
as magnesium and silicon, that
are necessary for forming rocky
planets like Earth. “How this material is ejected
and how this affects the
evolution of the star is however
still a mystery,” the RAS said.
http/www.vanguardngr.com

Hope its supernova will be visible here on earth... Would love to see it.