The GAPS programme with HARPS-N at TNG VI. The curious case of TrES-4b

We update the TrES-4 system parameters using high-precision HARPS-N radial-velocity measurements and new photometric light curves. A combined spectroscopic and photometric analysis allows us to determine a spectroscopic orbit with a semi-amplitude K = 51 +/- 3 ms(-1). The derived mass of TrES-4b is found to be M-p = 0.49 +/- 0.04 M-Jup, significantly lower than previously reported. Combined with the large radius (R-p = 1.84(-0.09)(+0.08) R-Jup) inferred from our analysis, TrES-4b becomes the transiting hot Jupiter with the second-lowest density known. We discuss several scenarios to explain the puzzling discrepancy in the mass of TrES-4b in the context of the exotic class of highly inflated transiting giant planets.

An education and training programme for radiological institutes: impact on the reduction of the CT radiation dose

To establish an education and training programme for the reduction of CT radiation doses and to assess this programme's efficacy.

Irradiated disks and planet population synthesis

Recent planet population synthesis models (Alibert et al. 2010, submitted) have emphasized the key role played by the proto-planetary disk properties in determining the overall planet population characteristics. We present a disk model that takes into account viscous heating and irradiation by a central star. We consider the case of an equilibrium flaring angle. We illustrate the consequences of the resulting changes in the disk structure on the planet population by the synthetic populations corresponding to each of the different structures.