High-precision photometry by telescope defocussing. V. WASP-15 and WASP-16

TL;DR

This study improves the physical and orbital parameters of the exoplanetary systems WASP-15 and WASP-16 through new high-precision photometric observations, revealing larger and less massive stars and planets in WASP-16.

Contribution

The paper provides new multi-band photometric data and refined measurements for WASP-15 and WASP-16, enhancing understanding of their physical properties and orbital characteristics.

Findings

WASP-15's parameters are consistent with previous measurements.

WASP-16's star and planet are larger and less massive than earlier estimates.

High-precision photometry improves exoplanet system characterization.

Abstract

We present new photometric observations of WASP-15 and WASP-16, two transiting extrasolar planetary systems with measured orbital obliquities but without photometric follow-up since their discovery papers. Our new data for WASP-15 comprise observations of one transit simultaneously in four optical passbands using GROND on the MPG/ESO 2.2m telescope, plus coverage of half a transit from DFOSC on the Danish 1.54m telescope, both at ESO La Silla. For WASP-16 we present observations of four complete transits, all from the Danish telescope. We use these new data to refine the measured physical properties and orbital ephemerides of the two systems. Whilst our results are close to the originally-determined values for WASP-15, we find that the star and planet in the WASP-16 system are both larger and less massive than previously thought.