Lot of new unpublished planets CHEPS

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Lot of new unpublished planets CHEPS

Post by Borislav on 1st January 2010, 6:42 am

http://arxiv.org/abs/0912.5325

The Calan-Hertfordshire Extrasolar Planet Search (aka. CHEPS) utilises the radial-velocity technique to monitor a number of bright, inactive and metal-rich, solar-type stars to hunt for the typical high frequency radial-velocity amplitude induced by an orbiting short period world

The current CHEPS target list is drawn from an initial southern sample of 350 stars that were observed with the ESO-FEROS spectrograph ([17]).

Therefore, we only consider stars with a FEROS iron abundance ratio +0.1 dex for our planet search project, which should help to bias the sample towards more gas giant-like exoplanets. In all, 100 stars were drawn from this pilot sample and almost all have been followed up with HARPS to hunt for short period planets.

Thus far the CHEPS has obtained at least three radial-velocity points for over 95% of this pilot sample using the ESO-HARPS instrument ([23]). Of these stars, a total of over 25 significant radialvelocity variations have been detected (after ruling out spectroscopic binary companions) giving rise to a high fraction of planet like signals (>25%).

Although we initially predicted a yield of 12 planets, as mentioned above, we currently show over 25 planetary-like signals in the pilot sample. This is because the [21] relation is only complete for gas giant planets down to minimum masses of 0.4MJ and with amplitudes (K) of >30ms−1, whereas within our planet-like signals we have a number of potential lower mass systems across a wide range of periods. Such systems require both time and data to properly confirm and constrain.

Borislav
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