부산대학교 도서관

A small fraction of Kepler telescope exposures are rejected because of transient, excess background in the field. The patterns of illumination vary from broad streaks to diffuse patches, sometimes filling the focal plane. Examination of such images and their temporal variation shows that they can be attributed to nearby particles crossing the field-of-view of the telescope. Most of the particles appear to be receding. The visual appearance and frequency are consistent with the "debris storms" reported by STEREO SECCHI observers and which they found to be coincident with meteoroid impacts. In addition, a few events, lasting several hours each, appear to be caused by more distant extended sources, possibly the remains of comet dust trails. The tracking cameras, located at the opposite end from the telescope's entrance, and pointed at roughly right angles to its line-of-sight, also detected moving light sources. Their behavior was consistent with the main telescope sightings. Future missions requiring precise, uninterrupted photometry and pointing may benefit from understanding this phenomenon and mitigating it by design and data analysis.