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arXiv · 2007.07278

Global Analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey

F. Lienhard·D. Queloz·M. Gillon·A. Burdanov·L. Delrez·E. Ducrot·W. Handley·E. Jehin·C. A. Murray·A. H. M. J. Triaud·E. Gillen·A. Mortier·B. V. Rackham
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Abstract

We conducted a global analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey - a prototype of the SPECULOOS transit search conducted with the TRAPPIST-South robotic telescope in Chile from 2011 to 2017 - to estimate the occurrence rate of close-in planets such as TRAPPIST-1b orbiting ultra-cool dwarfs. For this purpose, the photometric data of 40 nearby ultra-cool dwarfs were reanalysed in a self-consistent and fully automated manner starting from the raw images. The pipeline developed specifically for this task generates differential light curves, removes non-planetary photometric features and stellar variability, and searches for transits. It identifies the transits of TRAPPIST-1b and TRAPPIST-1c without any human intervention. To test the pipeline and the potential output of similar surveys, we injected planetary transits into the light curves on a star-by-star basis and tested whether the pipeline is able to detect them. The achieved photometric precision enables us to identify Earth-sized planets orbiting ultra-cool dwarfs as validated by the injection tests. Our planet-injection simulation further suggests a lower limit of 10 per cent on the occurrence rate of planets similar to TRAPPIST-1b with a radius between 1 and 1.3 $R_\oplus$ and the orbital period between 1.4 and 1.8 days.

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F. Lienhard, D. Queloz, M. Gillon, A. Burdanov, L. Delrez, E. Ducrot, W. Handley, E. Jehin, C. A. Murray, A. H. M. J. Triaud, E. Gillen, A. Mortier, B. V. Rackham. 2020-07-14. Global Analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey. https://doi.org/10.1093/mnras%2Fstaa2054

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