Simultaneous observation of TeV time-variable objects and gamma-ray burst afterglows with an optical telescope

我们与日本和澳大利亚机构合作，在位于南澳伍默拉的CANGAROO旁边安装了一个小型自动光学望远镜系统，这是一个由四台切伦科夫成像望远镜组成的阵列，用于甚高能伽马射线观测。该项目的主要目的是监测时变TeV天体，如活动星系核，并在光学波段对伽马射线爆发余辉进行后续观测。该系统由一台直径30 cm的施密特-卡塞格伦望远镜（米德LX 200 -30）和一台冷却的CCD相机（Apogee Ap-7 p）组成，由一台基于Linux的计算机通过网络进行控制。它配备了一个带约翰逊滤光片的自动滤光轮，因此可以进行多波长光度测定。观察小屋有一个自动屋顶，使用可以由计算机控制的电机。为了实现自动操作，它包括各种传感器，例如触发屋顶自动关闭的雨水监测器。我们在合作者的帮助下开发了所有这些软件。我们成功地用这个系统拍摄了一些测试图像。这个自动化系统已经在Woomera进行了最后的调整和测试。通过连续的网络连接，它可以用于伽马射线暴余辉的跟踪观测。

We installed a small automated optical telescope system next to CANGAROO, an array of four imaging Cherenkov telescopes for very-high-energy gamma-ray observation in Woomera, South Australia, in collaboration of Japanese and Australian institutions. The main aim of this project is to monitor time-variable TeV objects, such as active galactic nuclei, and to execute follow-up observations of gamma-ray burst afterglows in optical waveband. Also this telescope can be used to monitor atmospheric condition which is important in Cherenkov observations by observing starlight extinction near the field-of-view of the Cherenkov observations.The system consists of a 30-cm diameter Schmidt-Cassegrain telescope (Meade LX200-30) and a cooled CCD camera (Apogee Ap-7p) controlled by a Linux-based computer via a network. It is equipped with an automated filter wheel with Johnson filters, thus enabling multiwavelength photometry. The observation hut has an automatic roof with use of motors which can be controlled by the computer. For automatic operation it includes various sensors such as a rain monitor which triggers automatic closing of the roof. We developed the software for all of these with help of collaborators. We succeeded in taking some test images with this system. This automated system has been under final tuning and testing in Woomera. With a continuous network connection, it can be used for follow-up observation of gamma-ray burst afterglows.