Main-Belt Asteroids in the K2 Engineering Field of View

TL;DR

The paper investigates how main-belt asteroids affect the photometric precision of the K2 Mission, highlighting the need to account for asteroid contamination in data analysis for current and future space telescopes.

Contribution

It provides an analysis of asteroid contamination effects on K2 photometry and offers methods to recognize and distinguish these events from other errors.

Findings

Asteroids significantly impact K2 photometry during the mission.

Recognition methods for asteroid contamination are demonstrated.

Results applicable to future missions like TESS and PLATO.

Abstract

Unlike NASA's original Kepler Discovery Mission, the renewed K2 Mission will stare at the plane of the Ecliptic, observing each field for approximately 75 days. This will bring new opportunities and challenges, in particular the presence of a large number of main-belt asteroids that will contaminate the photometry. The large pixel size makes K2 data susceptible to the effect of apparent minor planet encounters. Here we investigate the effects of asteroid encounters on photometric precision using a sub-sample of the K2 Engineering data taken in February, 2014. We show examples of asteroid contamination to facilitate their recognition and distinguish these events from other error sources. We conclude that main-belt asteroids will have considerable effects on K2 photometry of a large number of photometric targets during the Mission, that will have to be taken into account. These results will be readily applicable for future space photometric missions applying large-format CCDs, such as TESS and PLATO.