Current Status of Observation and Research of Near-Sun Small Bodies

Abstract

Small solar system bodies with perihelion distances less than 0.307 AU/66 $R_{\odot }$ are known as near-Sun small bodies, and the extreme solar heating and high-temperature magnetized plasma environments they experience can reveal information about the small bodies themselves and contribute to the understanding of the near-solar space environment. Solar satellites have obtained a large amount of measured data of near-Sun small bodies, which provide opportunities for the study of the physical characterization and evolutionary history of different groups of near-Sun comets and asteroids, as well as the comparative study of the characteristics of extreme near-Sun comets (e.g., the Kreutz group) with those of other comets. Meanwhile, the observation of the coma and tail structure of near-Sun comets provides important references for the study of coronal properties such as the magnetic field structure of the solar system space, the velocity distribution of the solar wind, the coronal electron density, and the proton temperature. This article reviews the research progress made in the observation and in-situ exploration of near-Sun small bodies by solar satellites such as SOHO, STEREO, PSP, and SolO over the past 30 years, and introduces the corresponding research methods and technical methods. Finally, the article looks forward to the prospects and development directions of current and future domestic and international space and ground-based telescope observations of near-Sun small bodies.