Search for new celestial objects using microlensing effect

MOA项目的主要目标是搜索包含银河系相当一部分暗物质的非发光天体，以及搜索银河系中围绕遥远恒星运行的类地行星。重力微透镜现象为实现这两个目标提供了一个实用的程序。为了实现这些目标，2003年在日本组装了一台直径1.8米的广视场光学望远镜。同时，日本还制造了直径8米的望远镜穹顶和8000万像素的大型CCD相机。在2004年期间，望远镜、穹顶和照相机被安装在山上。新西兰坎特伯雷大学约翰天文台。第一次亮光出现在2005年3月1日。主要结果：2003年7月，通过引力微透镜首次明确发现了一颗太阳系外行星。这一发现是由MOA和OGLE团队共同完成的。随后，哈勃太空望远镜进行了更多的测量。此次发现的行星与木星相似，质量是木星的2.6倍，围绕着一颗质量为0.63太阳的恒星运行，轨道半径为4.3阿乌，2005年3月又发现了一颗质量为木星的行星。这一发现是在与OGLE、MicroFUN和PLANET/Robonet小组合作的高倍率微透镜事件中取得的。2005年4月，在与Ogle和MicroFun小组的合作下，在一次高倍事件中发现了一颗类似海王星的行星。最后，在2005年8月，在该行星和Ogle/Robonet小组的合作下，发现了一颗类似地球的行星。后者的发现表明，我们的太阳系在银河系中并不是一个孤独的系统

The main goals of the MOA project are the search for non-luminous astrophysical objects comprising a significant fraction of dark matter of the Galaxy, and also the search for Earth-like planets orbiting distant stars in the Galaxy. The phenomenon of gravitational microlensing offers a practical procedure for carrying out both these goals. To accomplish the goals, a wide-field optical telescope of diameter 1.8m was assembled in Japan during 2003. A telescope dome of diameter 8m, and a large CCD camera with 80 million pixels, were also fabricated in Japan at the same time. During 2004, the telescope, dome and camera were installed at the Mt. John Observatory of the University of Canterbury in New Zealand. First light occurred on March 1^<st> 2005.Main results: the first clear discovery of an extra-solar planet by gravitational microlensing occurred in July 2003. The discovery was made jointly by the MOA and OGLE groups. Additional measurements were subsequently made by the Hubble Space Telescope. The planet discovered in this event is similar to Jupiter.Its mass is 2.6 times that of Jupiter, and it orbits a star of 0.63 solar mass at an orbital radius of 4.3 AU.Another Jovian mass planet was found in March 2005. This discovery was made in a microlensing event of high magnification in collaboration with the OGLE, MicroFUN and PLANET/Robonet groups. During April 2005, a Neptune-like planet was found in an event of high magnification in collaboration with the OGLE and MicroFUN groups. Finally, in August 2005, an Earth-like planet was found in collaboration with the PLANET and OGLE/Robonet groups. The latter discoveries imply that our solar system is not a lonely system in our Galaxy