Development of optical/near infrared camera and long-term monitoring of target sources for VERA

VERA是日本国立天文台与鹿儿岛大学合作推出的一个新建成的VLBI阵列。VERA的目标是测量与银河系中的恒星形成区和Mira贵重物有关的脉泽源的弛豫。由于脉泽源具有很高的价值，为了更有效地进行长期的VLBI观测，监测其强度是很重要的。为此，我们计划开发一个1米的光学/近红外望远镜来监测VERA的目标源。此外，我们还计划利用VERA的6 m单碟射电望远镜和20 m天线对VERA观测的脉泽源进行巡天和监测观测，并证实VERA的双波束相位校准系统是利用相位参考观测的有力工具（Honma et al. 2003）。利用该系统，我们已经开始用VERA进行长期的VLBI监测观测。部分成果已在国内和国际会议上发表。此外，我们还利用VERA的6米射电望远镜和20米天线作为单碟射电望远镜，对几百个脉泽源进行了巡天和监测观测。我们目前正在建立脉泽源数据库，并将于近期公布，另一方面，我们已经研制了一台1米光学/近红外望远镜，并开始对Mira星进行监测观测。我们在调查中发现了一些不知名的米拉宝藏。为了准确地确定它们的周期，我们计划继续进行进一步的长期监测观察。

VERA is a newly constructed VLBI array promoted by National Astronomical Observatory of Japan in collaboration with Kagoshima University. VERA aims to measure the parallaxes of maser sources associated with star-forming regions and Mira valuables in the Galaxy. Because maser sources are highly valuable, it is important to monitor their intensities in order to carry out long-term VLBI observations more efficiently. For the purpose of this, we planned to develop a 1m optical/near infrared telescope to monitor the target sources for VERA. In addition, we planned to carry out survey and monitoring observations of maser sources observed with VERA with the 6m single-dish radio telescope and 20 m antenna of VERA.In our project, we confirmed that dual-beam phase calibration system of VERA is a powerful tool to use phase-referencing observations (Honma et al. 2003). Using this system, we have started to carry out long-term VLBI monitoring observations with VERA. Some of the results are presented in domestic and international conferences. In addition, we have started survey and monitoring observations of a few hundreds of maser sources using the 6m radio telescope and 20m antenna of VERA as a single-dish radio telescope. We are now constructing database of the maser sources and it will be published near future.On the other hand, we have developed a 1m optical/near infrared telescope and also started to carry out monitoring observations of Mira valuables. We found several unknown Mira valuables in our survey observations. In order to determine their period accurately, we are planning to continue further long-term monitoring observations.