A 40-cm infrared telescope in Antarctica

In Antarctica the cold and dry air is expected to provide the best observing conditions on the Earth for astronomical observations from infra-red to sub-millimeter. To enjoy the advantages in Antarctica, we have a plan to make astronomical observations at Dome Fuji, which is located at inland Antarctica. However, the harsh environment is very problematic. For example, the temperature comes down to as low as-80 degree Celsius in winter, where instruments designed for temperate environment would not work. In this context, we have developed a 40 cm infra-red telescope, which is dedicated for the use even in winter at Dome Fuji. In designing the telescope, we took account of the difference of the thermal expansion rate among materials, which were used for the telescope. Movable parts like motors were lubricated with grease which would be effective at -80 degrees. Most parts of the telescope are made of aluminum to make the telescope as light as possible, so that it makes the transportation from seacoast to inland and assembling at Dome Fuji easier. We also report the experiment that we have done at Rikubetsu (the coldest city in Japan) in February 2008.