Search for dark stars and planets by the grabitaional microlensing method

2005年，日本和新西兰的天文合作项目MOA(天体物理学中的微透镜观测)在约翰山安装了一台1.8米的望远镜。从那时起，每年都有500多次微透镜事件被发现朝向银河系隆起。这导致发现了53颗太阳系外行星，它们绕着银盘和星系隆起中的恒星运行。这些行星是在它们的宿主恒星的雪线之外发现的。这是微透镜技术最敏感的区域，也是根据核心吸积理论形成冰巨行星和气巨行星的区域。这些行星上的数据补充了通过径向速度和凌日技术获得的近距离行星上的数据。除了上述发现，MOA还发现了一类新的太阳系外行星。这些行星并不与恒星联系在一起。它们的质量与木星相似，它们的数量大约与银河系中的恒星一样多。

The Japan-NZ astronomy collaboration known as MOA (Microlensing Observations in Astrophysics) installed a 1.8m telescope at Mt John in 2005. Since that time more than 500 microlensing events have been found each year towards the galactic bulge.This resulted in the discovery of 53 extra-solar planets orbiting stars in the galactic disc and the galactic bulge. These planets were found just beyond the snowlines of their host stars. This is the region of maximum sensitivity of the microlensing technique, and it also the region where ice-giant and gas-giant planets form according to the core accretion theory. The data on these planets complements data being obtained on closer-in planets by the radial velocity and transit techniques. In addition to the above discoveries, a new class of extra-solar planets was discovered by MOA. These planets are not bound to stars. They have masses similar to that of Jupiter, and they are approximately as abundant as stars in the galaxy.