It is interesting too I think because it brings forward the possibility that
life may have started much earliar than now thought? ... perhaps?
It is an issue of "metallicity" I know ... I wonder what is the highest
atomic number element required by the simplest lifeform we know?
Al


"P. Backus" wrote in message
m...
It's a complicated story and the article doesn't tell it very well.
The age of the planet is inferred from the age of the stars. The
planet is in a "globular cluster". These clusters, typically
containing hundreds of thousands of stars, formed very early in the
history of our galaxy (and the universe).

Aside: Yes, "billion" is the American word for 10^9.

Each star orbits the center of mass of the cluster. Some stars are in
very elliptical orbits that take them into the very dense central
region of the cluster. When that happens, strong gravitational
interactions may occur. In most cases the star's orbit is simply
diverted into a new orbit. Sometimes multiple stars will interact and
one star (or planet) may be captured into a new orbit around another
star. That's apparently what happened in this case.

The planet is indeed in orbit about a star, in fact two stars. One of
the stars is a pulsar. It is through measuring the time interval
between the pulses from the pulsar over a span of many years that the
existence of the planet was discovered.

I hope that was more clear than the article.

"Robi" wrote in message
...
Seamus wrote:
http://www.space.com/scienceastronom..._030710-1.html

You know, I am really amazed how the age of a 'planet'
can be determined through a telescope. 12.7 billion years
(I suppose that's 12.7 milliard years or 12.7 *10^9 years)
I mean, look at the Earth, we're practically sitting on
top of it, and guess the age of it to be what,
4.5 billion[1] years old?
We can take rocks from the surface and from the soil and
analyze them with different methods, but to determine it
through a telescope... at 7.200 lightyears away... mind
boggling.
But now, isn't a planet supposed to turn around a star?
As I understand, this one doesn't... or I didn't get the
meaning out of this report...


[1] using the US billion (milliard or 10^9)