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تسجيل مستخدم جديدUniformly hot nightside temperatures on short-period gas giants
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Short-period gas giants (hot Jupiters) on circular orbits are expected to be tidally locked into synchronous rotation, with permanent daysides that face their host stars, and permanent nightsides that face the darkness of space. Thermal flux from the nightside of several hot Jupiters has been measured, meaning energy is transported from day to night in some fashion. However, it is not clear exactly what the physical information from these detections reveals about the atmospheric dynamics of hot Jupiters. Here we show that the nightside effective temperatures of a sample of 12 hot Jupiters are clustered around 1100 K, with a slight upward trend as a function of stellar irradiation. The clustering is not predicted by cloud-free atmospheric circulation models. This result can be explained if most hot Jupiters have nightside clouds that are optically thick to outgoing longwave radiation and hence radiate at the cloud-top temperature, and progressively disperse for planets receiving greater incident flux. Phase curve observations at a greater range of wavelengths are crucial to determining the extent of cloud coverage, as well as the cloud composition on hot Jupiter nightsides.
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Ultra-hot giant exoplanets receive thousands of times Earths insolation. Their high-temperature atmospheres (>2,000 K) are ideal laboratories for studying extreme planetary climates and chemistry. Daysides are predicted to be cloud-free, dominated by
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We report the discovery of a new ultra-short period hot Jupiter from the Next Generation Transit Survey. NGTS-6b orbits its star with a period of 21.17~h, and has a mass and radius of $1.330^{+0.024}_{-0.028}$mjup, and $1.271^{+0.197}_{-0.188}$rjup,
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