Search for rings and satellites around the exoplanet CoRoT-9b using Spitzer photometry

¹ Institut d’astrophysique de Paris, CNRS, UMR 7095 & Sorbonne Universités, UPMC Paris 6, 98bis Bd Arago, 75014 Paris, France
e-mail: lecaveli@iap.fr
² Observatoire de Haute-Provence, CNRS/OAMP, 04870 Saint-Michel-l’ Observatoire, France
³ Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
⁴ Universidad de La Laguna, Dept. de Astrofísica, 38206 La Laguna, Tenerife, Spain
⁵ INAF–Osservatorio Astrofisico di Torino, via Osservatorio 20, 10025 Pino Torinese, Italy
⁶ Observatoire de l’Université de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
⁷ Anton Pannekoek Institute for Astronomy, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
⁸ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
⁹ Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, 1053 Buenos Aires, Argentina
¹⁰ CONICET – Universidad de Buenos Aires, Instituto de Astronomía y Física del Espacio (IAFE), 1053 Buenos Aires, Argentina
¹¹ Canada-France-Hawaii Telescope Corporation, CNRS, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA

Received: 3 February 2017
Accepted: 29 April 2017

Abstract

Using Spitzer photometry at 4.5 microns, we search for rings and satellites around the long period transiting planet CoRoT-9b. We observed two transits in 2010 and 2011. From their non-detection, we derive upper limits on the plausible physical characteristics of these objects in the planet environment. We show that a satellite larger than about 2.5 Earth radii is excluded at 3σ for a wide range of elongations at the two epochs of observations. Combining the two observations, we conclude that rings are excluded for a wide variety of sizes and inclination. We find that for a ring extending up to the Roche limit, its inclination angle from the edge-on configuration as seen from the Earth must be lower than 13° in the case of silicate composition and lower than 3° in the case of material with water ice density.