# Extended Aperture Photometry of K2 RR Lyrae stars

## TL;DR

This paper introduces the Extended Aperture Photometry (EAP) method for K2 RR Lyrae stars, aiming to reduce instrumental variations by adapting apertures to star movements, and compares its effectiveness to existing pipelines.

## Contribution

The paper presents a novel EAP method that improves light curve quality for K2 RR Lyrae stars by accounting for positional changes during observations.

## Key findings

- EAP reduces instrumental variations compared to standard pipelines.
- EAP produces cleaner, more stable light curves.
- Comparison shows EAP outperforms K2SC in certain cases.

## Abstract

We present the method of the Extended Aperture Photometry (EAP) that we applied to K2 RR Lyrae stars. Our aim is to minimize the instrumental variations of attitude control maneuvers by using apertures that cover the positional changes in the field of view thus contain the stars during the whole observation. We present example light curves that we compared to the light curves from the K2 Systematics Correction (K2SC) pipeline applied to the automated Single Aperture Photometry (SAP) and to the Pre-search Data Conditioning Simple Aperture Photometry (PDCSAP) data.