A novel method for identifying exoplanetary rings

TL;DR

This paper introduces a new method to identify exoplanetary rings by analyzing transit depth anomalies and the photo-ring effect, enabling large-scale surveys to detect candidate ringed planets efficiently.

Contribution

It presents a novel, analytically simple approach to detect exorings through their large observational effects, suitable for application in extensive survey data like Kepler.

Findings

Large transit depth increases can misclassify ringed planets as false positives.

The photo-ring effect reveals discrepancies in stellar density measurements.

Method is effective for initial identification of ringed planet candidates.

Abstract

The discovery of rings around extrasolar planets ("exorings") is one of the next breakthroughs in exoplanetary research. Previous studies have explored the feasibility of detecting exorings with present and future photometric sensitivities by seeking anomalous deviations in the residuals of a standard transit light curve fit, at the level of ~100 ppm for Kronian rings. In this work, we explore two much larger observational consequences of exorings: (1) the significant increase in transit depth that may lead to the misclassification of ringed planetary candidates as false-positives and/or the underestimation of planetary density; and (2) the so-called "photo-ring" effect, a new asterodensity profiling effect, revealed by a comparison of the light curve derived stellar density to that measured with independent methods (e.g., asteroseismology). While these methods do not provide an unambiguous detection of exorings, we show that the large amplitude of these effects combined with their relatively simple analytic description, makes them highly suited to large-scale surveys to identify candidate ringed planets worthy of more detailed investigation. Moreover, these methods lend themselves to ensemble analyses seeking to uncover evidence of a population of ringed planets. We describe the method in detail, develop the basic underlying formalism and test it in the parameter space of rings and transit config- uration. We discuss the prospects of using this method for the first systematic search of exoplanetary rings in the Kepler database and provide a basic computational code for implementing it.