The discovery of WASP-151b, WASP-153b, WASP-156b: Insights on giant planet migration and the upper boundary of the Neptunian desert

摘要: To investigate the origin of features discovered in exoplanet population, knowledge exoplanets' mass and radius with a good precision is essential. In this paper, we report discovery three transiting exoplanets by SuperWASP survey SOPHIE spectrograph determined better than 15 %. WASP-151b WASP-153b are two hot Saturns masses, radii, densities equilibrium temperatures 0.31^{+0.04}_{-0.03} MJ, 1.13^{+0.03}_{-0.03} RJ, 0.22^{-0.03}_{-0.02} rhoJ 1, 290^{+20}_{-10} K, 0.39^{+0.02}_{-0.02} 1.55^{+0.10}_{-0.08} 0.11^{+0.02}_{-0.02} 700^{+40}_{-40} respectively. Their host stars early G type (with magV ~ 13) their orbital periods 4.53 3.33 days, WASP-156b Super-Neptune orbiting K star (magV = 11.6) . It has 0.128^{+0.010}_{-0.009} 0.51^{+0.02}_{-0.02} density 1.0^{+0.1}_{-0.1} rhoJ, an temperature 970^{+30}_{-20} period 3.83 days. slightly inflated, while presents significant anomaly. WASP-156b, being one few well characterised Super-Neptunes, will help to constrain formation Neptune size planets transition between gas ice giants. The estimates age these confirms tendency for some have gyrochronological ages significantly lower isochronal ages. We propose that high eccentricity migration could partially explain behaviour hosting short planet. Finally, also lie close (WASP-151b WASP-153b) or below (WASP-156b) upper boundary Neptunian desert. characteristics support ultra-violet irradiation plays important role depletion observed population.