Towards the systematic detection of active asteroid candidates: A photometric method

Abstract

ABSTRACT The Active Asteroids (AAs), are a small population of minor planets with characteristics similar to both asteroids and comets. In the search for the AAs, the analysis of light curves promises to be an efficient approach to identify candidates. In an effort towards an automatable method to detect AA candidates (AAc) through light curve analysis, in this work, we present a comprehensive comparison of the methodologies used for the reduction of the photometric data in previous works against other variations proposed here. We analyse the impact of different phase models in the reduction of the data and in the analysis of light curves. As a proof of concept, we studied a random sample of 1000 asteroids from the IAU’s Minor Planet Center (MPC) Observation Database. The aim is to both test the methodology and search for AAc among them. The constraints imposed on the sample were that more than 150 photometric observations spanning all bands and a perihelion distance of q < 2.7 au are required for each object. We find that it is preferred, for the purpose of decreasing the possibility of false-positive detections, to reduce and analyse the photometric data from different bands independently, rather than doing it jointly with a one-size-fits-all correction, as done in previous works. We found strong indicators of activity in the light curves of five asteroids: (2776) Baikal, (11456) Cotto-Figueroa, (12528), (66944), and (71907). Other two asteroids, numbered (12871) and (329604), show signs of activity, but the indicators are not as strong.