Revised Orbital Solutions for 94 Exoplanetary Systems

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Revised Orbital Solutions for 94 Exoplanetary Systems

Post by Edasich on 4th January 2012, 9:14 am

Many interesting new planets and revised orbital solutions. Many Trojan planets and additional low-mass ones. I wonder if EPE is going to list them.

A Uniformly Derived Catalogue of Exoplanets from Radial Velocities

A new catalogue of extrasolar planets is presented by re-analysing a selection of published radial velocity data sets using EXOFIT (Balan & Lahav 2009). All objects are treated on an equal footing within a Bayesian framework, to give orbital parameters for 94 exoplanetary systems. Model selection (between one- and two-planet solutions) is then performed, using both a visual flagging method and a standard chi-square analysis, with agreement between the two methods for 99% of the systems considered. The catalogue is to be made available online, and this 'proof of concept' study may be maintained and extended in the future to incorporate all systems with publicly available radial velocity data, as well as transit and microlensing data.
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Re: Revised Orbital Solutions for 94 Exoplanetary Systems

Post by Sirius_Alpha on 4th January 2012, 10:53 am

I'm not sure these constitute actual discoveries. I haven't read the paper yet but it seems to me that these two-planet solutions are a bit forced onto the data. I'm not sure they're meant to be considered real.

Look at Table 6 toward the end. You can see that this analysis has a two-planet solution providing a better fit to only four systems that aren't already known to poses two planets. For the vast majority of two-planet solutions, the fit is not improved by the addition of a second planet.

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Re: Revised Orbital Solutions for 94 Exoplanetary Systems

Post by Edasich on 5th January 2012, 6:36 am

Yes, indeed some are so unrealistic and have quite large ranges of uncertainty. To say, the putative 2nd planet HD 189733 c seems to lay in almost the same orbital region of planet b but with eccentricity as high as 0.96. Quite not.
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