The recent discovery of a trio of Earth-like exoplanets 39 light years away from Earth(1) reinforces the need for more sensitive detection systems to survey the sky. The launch of the Andor iKon-XL Very Large Area (VLA) Astronomy CCD and its successful placement on a new planetary transit survey telescope on the Antarctic Plateau raises the prospect of more breakthroughs to come.
The iKon-XL VLA is purpose-designed to suit the long-exposure needs of astrophysical surveys that have, until now, been heavily reliant on conventional CCD cameras. Patent-pending ColdSpace technology cools the very large 16.8 Megapixel sensor to -100°C, avoiding the need for liquid nitrogen or unreliable cryo coolers, while the large 12 µm pixels bring maximum photon capture. The result is industry-leading low noise performance and exceptional extended dynamic range that is complemented by up to 18-bit digitisation and up to 95% QE performance from UV to NIR.
All of these technological advances are integrated within the robust, low maintenance, design making it ideal for many experimental set-ups, including in remote astronomical observing sites. This was especially important for the new Bright Star Survey Telescope in Antarctica, where the continuous darkness and large clear-sky fraction in the winter months greatly enhance the detection efficiency but the equipment has to survive temperatures as low as -80ËC with the mean temperature of -56°C. Since the mechanical shutter of the iKon-XL must be above 0°C, Andor designed a special thermally-controlled, titanium alloy shutter housing that maintains the temperature of the entire shutter mechanism to within 0.1°C
The BSST with its iKon-XL camera has now completed test observations, during which the optical design and temperature alignment tolerances were verified. During these trials, the BSST also successfully observed transiting events of two exoplanets, called HAT-P-3b and HAT-P-12b. Dr. Zhengyang Li, from the Nanjing Institute of Astronomical Optics and Technology, China, says “the optical design and tolerance analysis guarantee the quality of BSST. The test observations reveal exceptionally clear single star images with a photometric precision of 3.5 mmag achieved for magnitude 11 stars with just 75 s exposures.”
According to Colin Coates of Andor, an Oxford Instruments company, “Antarctica is a hugely promising site for planetary transit surveys, where the continuous darkness and the large clear-sky fraction in the winter months greatly enhance the detection efficiency. However, the extreme environment, with a mean temperature of -56°C, brings huge technical challenges that must be overcome. Our custom-designed thermally-controlled shutter housing performed faultlessly and is essential to the success of the BSST.
Our range of CCD and EMCCD cameras has been the detector of choice for a very large part of the current crop of terrestrial telescopes. Now, with the addition of the Andor iKon-XL Very Large Area (VLA) Astronomy CCD we are set to build on that dominant position.”
1. Michaël Gillon, Emmanuël Jehin, Susan M. Lederer, Laetitia Delrez, Julien de Wit, Artem Burdanov, Valérie Van Grootel, Adam Burgasser, Cyrielle Opitom, Amaury H. M. J. Triaud, Brice-Olivier Demory, Devendra K. Sahu, Daniella Bardalez Gagliuffi, Pierre Magain & Didier Queloz.“Temperate Earth-Sized planets transiting a nearby ultracool dwarf star” Nature (2016) doi:10.1038/nature17448
2. Qiguo Tian, Peng Jiang, Fujia Du, Jian Wang, Zhengyang Li, Xiaoyan Li, Zhiyong Zhang, Haiping Lu, Xiangyan Yuan, Huigen Liu, Hui Zhang, Luming Sun, Liang Chang, Jianguo Wang, Shaohua Zhang, Tuo Ji, Xiheng Shi, Jie Chen, Guangyu Zhang, Minghao Jia, Jiajing Liu, Junyan Zhou, Xiang Pan, Shucheng Dong, Fengxin Jiang, Hongfei Zhang, Jilin Zhou, Lifan Wang, Hongyan Zhou. “The bright star survey telescope for the planetary transit survey in Antarctica” Sci. Bull. (2016) 61(5):383–390 DOI 10.1007/s11434-016-1015-0