Hunting For Other Planets

wrote:
Out of curiousity in regards to the search for Extrasolar planets, why
are planet hunters studying worlds hundreds of light years away when we
have several star systems in our own back yard that don't seem to get
much attention, and in theory wouldn't their closer proximity make them
easier to search for and study possible planets?

Food for thought: at this point in extra-solar planet finding
technology, astronomers could not detect the planets of the Solar
System if the astronomers were in Alpha Centauri.

Basically, being close does not make it easier to spot planets. The
methods currently being used to find extra-solar planets require
certain rare sets of circumstances. The planets have to fall into the
following categories (roughly speaking):

1) Big and close to a star, so the wobble on the star is obvious
2) Pass between the star and Earth, so the slight dimming effect is
noticeable.

That's not the complete story, but planets that meet those conditions
(especially the first) are currently easiest to find, AFAIK. Nearby
solar systems generally don't have those conditions.

Mike Miller

wrote in message
oups.com...


wrote:
Out of curiousity in regards to the search for Extrasolar planets, why
are planet hunters studying worlds hundreds of light years away when we
have several star systems in our own back yard that don't seem to get
much attention, and in theory wouldn't their closer proximity make them
easier to search for and study possible planets?

Food for thought: at this point in extra-solar planet finding
technology, astronomers could not detect the planets of the Solar
System if the astronomers were in Alpha Centauri.

Basically, being close does not make it easier to spot planets. The
methods currently being used to find extra-solar planets require
certain rare sets of circumstances. The planets have to fall into the
following categories (roughly speaking):

1) Big and close to a star, so the wobble on the star is obvious
2) Pass between the star and Earth, so the slight dimming effect is
noticeable.

That's not the complete story, but planets that meet those conditions
(especially the first) are currently easiest to find, AFAIK. Nearby
solar systems generally don't have those conditions.

So you're saying they have looked for planets there, but found none?

Paul O'Neill wrote:
So you're saying they have looked for planets there, but found none?

I said nothing of the sort. Over 100 extra-solar planets have been
found.

Mike Miller

In article ,
"Paul O'Neill" wrote:

Basically, being close does not make it easier to spot planets. The
methods currently being used to find extra-solar planets require
certain rare sets of circumstances. The planets have to fall into the
following categories (roughly speaking):

1) Big and close to a star, so the wobble on the star is obvious
2) Pass between the star and Earth, so the slight dimming effect is
noticeable.

That's not the complete story, but planets that meet those conditions
(especially the first) are currently easiest to find, AFAIK. Nearby
solar systems generally don't have those conditions.

So you're saying they have looked for planets there, but found none?

Right, which doesn't imply anything about whether planets exist -- it
implies only that planets *of the sort we can detect* do not exist. No
massive, super-Jupiter-sized planets orbiting very close to the star.

This is actually a good thing, if you're interested mainly in
terrestrial planets. The hot Jupiters we're mostly able to find at this
point don't bode well for terrestrial planets in the same system.

,------------------------------------------------------------------.
| Joseph J. Strout Check out the Mac Web Directory: |
| http://www.macwebdir.com |
`------------------------------------------------------------------'