Document Type
Article
Publication Date
7-1-2019
Abstract
In its Campaign 9, K2 observed dense regions toward the Galactic bulge in order to constrain the microlensing parallaxes and probe for free-floating planets. Photometric reduction of the K2 bulge data poses a significant challenge due to a combination of the very high stellar density, large pixels of the Kepler camera, and the pointing drift of the spacecraft. Here we present a new method to extract K2 photometry in dense stellar regions. We extended the Causal Pixel Model developed for less-crowded fields, first by using the pixel response function together with accurate astrometric grids, second by combining signals from a few pixels, and third by simultaneously fitting for an astrophysical model. We tested the method on two microlensing events and a long-period eclipsing binary. The extracted K2 photometry is an order of magnitude more precise than the photometry from other method.
Publication Source (Journal or Book title)
Astronomy and Astrophysics
Recommended Citation
Poleski, R., Penny, M., Gaudi, B., Udalski, A., Ranc, C., Barentsen, G., & Gould, A. (2019). Photometry of K2 Campaign 9 bulge data. Astronomy and Astrophysics, 627 https://doi.org/10.1051/0004-6361/201834544