Photometric stellar variation due to extra-solar comets

TL;DR

This paper explores how photometric variations caused by extra-solar comets can be detected through numerical simulations, revealing characteristic light curves and estimating detection rates in large surveys to study exoplanetary system evolution.

Contribution

It introduces a method to detect extra-solar comets via photometric variations and estimates detection rates in large-scale surveys, highlighting potential for studying exoplanetary system evolution.

Findings

Extra-solar comets cause detectable photometric variations.

Light curves often have a 'rounded triangular' shape.

Large surveys could detect hundreds of comet occultations annually.

Abstract

We performed numerical simulations of stellar occultations by extra-solar cometary tails. We find that extra-solar comets can be detected by the apparent photometric variations of the central stars. In most cases, the light curve shows a very peculiar ``rounded triangular'' shape. However, in some other cases, the curve can mimic a planetary occultation. Photometric variations due to comet occultations are mainly achromatic. Nevertheless, if comets with small periastrons have smaller particles, these occultations could be chromatic with a larger extinction in the blue by few percents. We also estimate the number of detections expected in a large photometric survey at high accuracy. By the observation of several tens of thousand of stars, it should be possible to detect several hundreds of occultation per year. We thus conclude that a spatial photometric survey would detect a large number of extra-solar comets. This would allow to explore the time evolution of cometary activity, and consequently would probe structure and evolution of extra-solar planetary systems.