Timing asteroid occultations by photometry

Observations of stellar occultation by asteroids provide opportunities to directly measure dimensions and study physical parameters of asteroids. Existing asteroid occultation timing methods either record the occultation time directly or compute the occultation time from the measurement of length. In this work, we present a timing method to derive the occultation time from the measurement of magnitude, termed Integration Photometric Timing (IPT), which simply utilizes CCD photometry with relatively long exposures. Applications to two events, (3) Junoʹs and (980) Anacostiaʹs, are given to demonstrate the use and feasibility of the IPT. The proposed method has the capability of timing asteroid occultations of faint stars because of its long exposure time. Thus, more observable events are expected, with professional large telescopes to be involved in asteroid occultation observations, especially for the case of Kuiper belt objects (KBOs) and other distant asteroids occultation.