Re: Number of low eccentricity distant planets

Wasn't it Crown-Horned Snorkack who wrote:
>Hot jupiters are easier to detect than the more distant planets like
>Solar System giants. However, some planets on long period orbits have
>been found.
>
>Planets on circular orbits, like in Solar System, should be no harder
>to find than planets on eccentric orbits. Yet most planetary systems
>have eccentric orbits.
>
>How rare are systems with low eccentricity orbits like Solar System -
>excluding the hot jupiters?

This page lists extrasolar planets detected by radial velocity ordered 
by eccentricity
    http://exoplanet.eu/catalog-RV.php?&mode=5
(You can order by any column by clicking on the column name).

Decide what value you consider to be "low eccentricity" and count off 
the pro****tion. As a guide, the eccentricity of the Earth is 0.0167. 
About 16% of those extrasolar planets have orbits that are less 
eccentric than that of the Earth. I ignored exoplanets for which the 
eccentricity has not been calculated.

This page allows you to display a histogram of exoplanet eccentricities.
    http://exoplanet.eu/catalog-RV.php?mdAff=stats#tc
Choose "Planet Ecc" as the "Ref" field.

You can also use that page to produce a correlation diagram. If you plot
Planet Mass (log) vs Planet Eccentricity (linear) you'll see that 
there's a slight tendency for low mass planets to have more circular 
orbits.

-- 
Mike Williams
Gentleman of Leisure