摘要: | It is of great importance to know evolution of solar system small bodies. Asteroids that have survived since the early solar system (4.6 Gyr ago) have experienced numerous collisions that influenced thermal histories and orbital properties. Thus, the physical nature (size, shape, density, composition and orbital distribution) of asteroids is fundamental to understanding how our solar system has been evolved. Some asteroids are in fact either dead or dormant cometary nuclei. Though an Earth impact of 1 km-size asteroid is likely within a million years, frequent fireballs or meteorite falls on Earth are indications of collisional (ejection) events. Asteroidal particles have been proposed as a source of some meteor showers. However, their parent bodies and dynamical evolution of meteoroids are still subject to debate. The final goal of this research work is to generate new insights for, “ how are our solar system small bodies (asteroids, comets and meteoroids) generated and how are they evolved and linked? ”. In order to make quantitative understanding, I plan to perform innovative approaches with a wide field of vision using the panoramatic survey telescope (Pan-STARRS) together with the Taiwanese newly installed 2-m telescope and meteor orbital determination system (imaging and spectroscopy), that have never ever examined before. The Panoramatic Survey Telescope And Rapid Response System (Pan-STARRS) is a project, initiated by the University of Hawaii, to repeatedly survey covering three quarters of the entire sky to discover a very large number of new asteroids and comets down to apparent magnitude of approximately 23. The operations for the first Pan-STARRS telescope (PS1) are funded by a consortium including National Central University (NCU) in Taiwan. On the other hand, NCU will install new 2-m telescope at the Lulin Observatory by 2009. Taiwanese 2-m telescope is capable of follow-up for fainter near-Earth asteroids (NEOs) captured by PS1's 1.8-m telescope. In particular for Potentially Hazardous Asteroids (PHAs), which motion is faster than other NEOs, our rapid follow-up (6-hour time difference from Hawaii) is an integral part of PHA discovery. In addition, we have a great advantage to concentrate on investigating physical properties of discovered asteroids using multi-color photometry and spectroscopy. More than 200 potential meteor showers were observed, however, the sources of minor meteor showers are still unclear. Of particular interest is whether these weak showers originate from faint comets, dormant comets or asteroids. Some asteroids are thought to be larger fragments produced by the breakup of a precursor object. Asteroidal meteor showers should be smaller fragments caused by this breakup. However, the orbits of minor meteor showers have large uncertainties, owing to the observational biases, e.g., the small number of measured orbits and observational limiting magnitude. In order to investigate the meteoroid orbit statistically, imaging with spectroscopic observations of meteors will be carried out using the automatic detection system, that has a great advantage for minor meteor showers. Quantitative understanding of the connection among small bodies and their association with meteoroids will generate new insights of our solar system. 研究期間:9908 ~ 10007 |