Peculiar architectures for the WASP-53 and WASP-81 planet-hosting systems

We report the detection of two new systems containing transiting planets. Both were identified by WASP as worthy transiting planet candidates. Radial velocity observations quickly verified that the photometric signals were indeed produced by two transiting hot Jupiters. Our observations also show the presence of additional Doppler signals. In addition to short-period hot Jupiters, we find that the WASP-53 and WASP-81 systems also host brown dwarfs, on fairly eccentric orbits with semimajor axes of a few astronomical units. WASP-53c is over 16 MJupsin ic and WASP-81c is 57 MJupsin ic. The presence of these tight, massive companions restricts theories of how the inner planets were assembled. We propose two alternative interpretations: the formation of the hot Jupiters within the snow line or the late dynamical arrival of the brown dwarfs after disc dispersal. We also attempted to measure the Rossiter–McLaughlin effect for both hot Jupiters. In the case of WASP-81b, we fail to detect a signal. For WASP-53b, we find that the planet is aligned with respect to the stellar spin axis. In addition we explore the prospect of transit-timing variations, and of using Gaia's astrometry to measure the true masses of both brown dwarfs and also their relative inclination with respect to the inner transiting hot Jupiters.Publisher PDFPeer reviewe

Sentinel-2 Level-1 Calibration and Validation Status from the Mission Performance Centre

International audienceAs part of the Copernicus programme of the European Commission (EC), the European Space Agency (ESA) operates the Sentinel-2 mission that acquires high spatial resolution optical imagery. The consistency of the image time series is ensured by some specific performance requirements such as multi-temporal spatial registration and radiometric stability, routinely monitored by the Sentinel-2 Mission Performance Centre (S2MPC). The products also provide a rich set of metadata and auxiliary data to support high-level processing activities. This presentation provides a description of the main level-1 products calibration and validation activities, performed by the S2MPC including several Expert Support Laboratories (ESL). Measured performances and analysed results show the good quality of the mission products both in terms of radiometry and geometry. The current performances for Sentinel-2A and Sentinel-2B are compared to mission product quality requirements

Peculiar architectures for the WASP-53 and WASP-81 planet-hosting systems

We report the detection of two new systems containing transiting planets. Both were identified by WASP as worthy transiting planet candidates. Radial velocity observations quickly verified that the photometric signals were indeed produced by two transiting hot Jupiters. Our observations also show the presence of additional Doppler signals. In addition to short-period hot Jupiters, we find that the WASP-53 and WASP-81 systems also host brown dwarfs, on fairly eccentric orbits with semimajor axes of a few astronomical units. WASP-53c is over 16 MJupsin ic and WASP-81c is 57 MJupsin ic. The presence of these tight, massive companions restricts theories of how the inner planets were assembled. We propose two alternative interpretations: the formation of the hot Jupiters within the snow line or the late dynamical arrival of the brown dwarfs after disc dispersal. We also attempted to measure the Rossiter–McLaughlin effect for both hot Jupiters. In the case of WASP-81b, we fail to detect a signal. For WASP-53b, we find that the planet is aligned with respect to the stellar spin axis. In addition we explore the prospect of transit-timing variations, and of using Gaia's astrometry to measure the true masses of both brown dwarfs and also their relative inclination with respect to the inner transiting hot Jupiters