planets around metal-poor stars

It is well known that the current census of extrasolar planets shows
an interesting correlation with their host stars: An extrasolar
planet is more likely to be found around a high metallicity star than
around a low metallicity star. (Here "metallicity" is the standard
astronomiccal usage meaning any element heavier than helium.)

I ran across the following interesting comment in an abstract by
Sozzetti et al., "A Keck/HIRES Doppler Search for Planets Orbiting
Metal-Poor Dwarfs":

We present results from our ongoing spectroscopic search for giant
planets within 1 AU around a well-defined sample of metal-poor stars
[...]. However, about 7% of the stars in our sample exhibits velocity
trends indicative of the existence of companions. [...]

In other words, be careful of selection effects!

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Joseph Lazio wrote in message
SNIP

I ran across the following interesting comment in an abstract by
Sozzetti et al., "A Keck/HIRES Doppler Search for Planets Orbiting
Metal-Poor Dwarfs":

We present results from our ongoing spectroscopic search for giant
planets within 1 AU around a well-defined sample of metal-poor stars
[...]. However, about 7% of the stars in our sample exhibits velocity
trends indicative of the existence of companions. [...]

In other words, be careful of selection effects!

I would not be surprised to find gas giants around metal-poor stars,
consisting of H and He.

But the more important terrestial planets won't be there.

And life won't be there either, with no 'metals' like carbon, iron
etc.

Regards

Carsten Nielsen
Denmark

Dear Carsten Nielsen:

"Carsten Nielsen" wrote in message
om...
Joseph Lazio wrote in message
SNIP

I ran across the following interesting comment in an abstract by
Sozzetti et al., "A Keck/HIRES Doppler Search for Planets Orbiting
Metal-Poor Dwarfs":

We present results from our ongoing spectroscopic search for giant
planets within 1 AU around a well-defined sample of metal-poor stars
[...]. However, about 7% of the stars in our sample exhibits
velocity
trends indicative of the existence of companions. [...]

In other words, be careful of selection effects!

I would not be surprised to find gas giants around metal-poor stars,
consisting of H and He.

But the more important terrestial planets won't be there.

And life won't be there either, with no 'metals' like carbon, iron
etc.

Life is nothing if not pervasive. I'd be really surprised if life were not
simply more efficient at working around "plenty". God help the metal-rich
object that might drift in from elsewhere...

David A. Smith

Carsten Nielsen wrote:

I would not be surprised to find gas giants around metal-poor stars,
consisting of H and He.

I believe the theory under test is that gas giants can't form without
accretion onto a rocky core. If a Jupiter-like planet is found around a
metal-poor star, then fewer metals are needed or the formation scenario
is wrong.
--
Bill Wyatt ) "remove this" for email
Smithsonian Astrophysical Observatory (Cambridge, MA, USA)

"BW" == Bill Wyatt writes:

BW Carsten Nielsen wrote:
I would not be surprised to find gas giants around metal-poor
stars, consisting of H and He.

BW I believe the theory under test is that gas giants can't form
BW without accretion onto a rocky core. If a Jupiter-like planet is
BW found around a metal-poor star, then fewer metals are needed or
BW the formation scenario is wrong.

There is at least one planet found in the metal-poor globular cluster M4.

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