Possibly of interest: Very old star discovered
- Saw this on BBC News.
Mark A. Holmes
Relic star poses cosmic puzzles
Astronomers have identified what could be one of the
earliest stars formed in the Universe, Nature magazine
Scientists think the cosmic relic may consist largely
of elements created in the hot gas that existed just
15 minutes after the Big Bang.
The star has a very low iron content - an elemental
signature that suggests it is made of fresh material
that was never processed by an earlier star.
But other such signatures are unusual for a very
primitive stellar object.
The new star HE0107-5240 and another star called
HE1327-2326 have the lowest abundances of heavy
About 13.7 billion years ago, the Universe consisted
of a hot gas with a temperature high enough to produce
the lightest chemical elements.
The rapid expansion after the first 15 minutes of the
Universe put an end to the synthesis of new elements
by the process of nucleosynthesis.
However, after about 200 million years, the Universe
grew large enough for haloes of dark matter to form
and this triggered the formation of the first stars.
These first stars synthesised all the heavier
elements, from carbon to uranium, that form the basis
of solid planets and organic life.
Over the past 25 years, astronomers have been scouring
the skies for stars with a composition that reflects
these first stellar objects.
The new star HE1327-2326 has an unexpectedly low
abundance of the metal lithium and an unexpectedly
high amount of the metal strontium for such a
"The lithium problem is immediately more troublesome.
Many of the primitive stars studied in the past have
lithium abundances that are very similar to one
another," said co-author Timothy Beers, of Michigan
State University in East Lansing, US.
"It's remarkable but apparently what we see in these
stars is the tiny amount of lithium produced in the
"Yet in this star, it's not at that perfect value, so
we're a bit confused as to why that might be."
Further research on this star and others like it may
help shed light on where the lithium in primitive
stars came from.
"When we get such extreme objects as this it really
forces the people who model how these elemental
abundances come about to take a close look at what
they might be missing," Professor Beers told BBC News.
One possibility is HE1327-2326 is a binary system. If
the primitive star's binary companion had the
opportunity to evolve, it might start to synthesise
heavier metals including strontium.
The evolving binary might then cast off its outer
envelope, allowing some of the material to be accepted
by its primitive companion, explaining the high
The research was an international collaboration
involving researchers from Australia, Japan, Germany,
Sweden and the US.
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around