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

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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.