K2 Looks Towards WASP-28 and WASP-151

TL;DR

This study refines the parameters of two exoplanets using K2 photometry, reports non-detections of variations, and discusses background events likely caused by Mars crossing the field of view.

Contribution

It provides improved system parameters for WASP-28b and WASP-151b and analyzes background events in K2 data, offering insights into observational artifacts.

Findings

Refined parameters for WASP-28b and WASP-151b.

No significant transit-timing or duration variations detected.

Background brightening events likely caused by Mars.

Abstract

By analysing the short-cadence K2 photometry from the observing Campaign 12 we refine the system parameters of hot Jupiter WASP-28b and hot Saturn WASP-151b. We report the non-detection and corresponding upper limits for transit-timing and transit-duration variations, starspots, rotational and phase-curve modulations and additional transiting planets. We discuss the cause of several background brightening events detected simultaneously in both planetary systems and conclude that they are likely associated with the passage of Mars across the field of view.