兴隆1m光学望远镜消杂散光系统

Stray light control lens for Xing Long 1-meter optical telescope

为优化兴隆1m光学望远镜的杂散光效应,研制了附加在该望远镜F/8焦面后的"一倍放大率消杂散光镜头",对消杂散光镜头的效果进行了仿真计算和观测验证。在Tracepro软件中对"圆顶-1m望远镜"和"圆顶-1m望远镜-消杂散光镜头"组合系统的"点源辐照度透过率(PSNIT)"进行了计算分析并在大月夜进行了天文观测。计算结果表明,在视场外无限远点源方位与望远镜指向间夹角5°≤|θ|≤30°使用消杂散光镜头后,该望远镜PSNIT全部降低到10-10以下。2008年5月26日对偏月22°和25°天区观测结果表明,使用消杂散光镜头后,该望远镜所观测的星像信噪比约为原来的1.4倍。仿真计算和观测结果表明:该方法对Ritchey-Chrétien(R-C)望远镜的杂散光抑制是有效的,可以提高望远镜的测光精度和观测极限星等。

To reduce the stray light effect of Xing Long 1-meter optical telescope, an objective lens was developed, and simulations and observations were undertaken to evaluate the lens. The Point Source Normalized Irradiance Transmission（PSNIT） for＂dome-telescope＇and ＂dome-telescope-lens＂ systems was calculated with the code Tracepro and observations were carried out at a moon night. The calculation results indicate that for the stray light sources located at off-axis angle within 30°, the PSNITs of the observational system, including dome, 1 m telescope and the lens, have been lower than 10-^10. Furthermore, the observation results for stars located at 22°and 25°off-axis angles away from the moon in May 26th 2008 indicate that the observational SNR of the system has been increased by a factor about 1.4 with the lens. These results show that for the 1-meter optical telescope the stray light is reduced and the photometric accuracy and limiting magnitude are improved by the lens effectively.