Survey Observation of Short-Period Mira Variables Using a Very Wide Field Near-Infrared Camera

这个项目的最终目标是使用短周期米拉型变星作为距离探测器来揭示我们银河系的结构。作为这一项目的第一步，我们研制了一套安装在冈山天体物理观测站91厘米望远镜上的宽视场近红外相机系统，作为主要观测仪器。该宽视场相机具有在近红外J、H和K波段的极宽视场成像能力，其宽度可达1度平方。成功搭建了大视场相机的光学系统和探测系统。我们仔细地对相机露水进行了冷却测试，确认了露水具有良好的冷却能力。我们还对91厘米的望远镜进行了更新。我们制作了一个新的次镜及其支撑系统，以及一个用于广域相机的连接系统。为了提高91厘米望远镜主镜在近红外波段的反射率，对主镜进行了镀金处理。对望远镜控制系统的硬件和软件进行了彻底的改造。我们在检查仪器的同时，详细地检查了调查观察策略。此外，我们还多次出国出差，参加了一些国际会议，与外国调查人员交流技术和科学信息。虽然在本研究期间，我们没有开始真正的测量观测，但我们成功地完成了最初计划的仪器。

The final goal of this project is revealing the structure of our Galaxy using short period Mira type variables as distance probes. For the first step of this project, we developed a wide-field near-infrared camera system attached to the 91cm telescope of Okayama Astrophysical Observatory as the main observational instrument. The wide-field camera has a capability of very wide-field imaging which is as wide as 1 degree square in near-infrared J, H, and K bands. We successfully constructed the optics and the detector system of the wide-field camera. We performed cooling tests for the camera dewer carefully and confirmed that the dewer has a good cooling capability. We also made renewal of the 91cm telescope. We made a new secondary mirror, its support system, and an attachment system for the wide-field camera. The primary mirror of the 91cm telescope was recoated with gold in order to improve its reflectivity in near-infrared band. We completely remade the hardware and the software of the telescope control system. We examined the survey observation strategy in detail in parallel with the instrumentation. Furthermore, we went on several business trips abroad, attended some international conferences for exchanging technical, scientific information with foreign investigators. Although we could not start real survey observation in this research period, we successfully completed the instrumentation which we had planned at first.