Testing AST3-II in Mohe

Because the 30rd Chinese Antarctic Research Expedition Team went to a new site 520km away from Zhongshan Station to build a new station called Taishan instead of exploring Kunlun Station in Dome A this year, the second AST3 was shipped to Mohe in Heilongjiang Province, where is the northernmost place of China, for low temperature testing.  

The telescope arrived in the middle of November in 2013, and was placed in a village near Heilongjiang River — the border between China and Russia. It was assembled soon by the people from NIAOT and then wait for the camera. Meanwhile, the CCD camera arrived in the end of November in 2013 from STA company in the USA. After some short-term low temperature examination in our group lab, one of my colleague and me took the camera to Mohe on 2nd December in 2013. After a few days of assembling and debugging, the telescope start working. So far, the telescope was still running smoothly in a moderate cold ambience, at least from my perspective. I am in charge of building computers and associated devices for operating telescope, grabbing images, storing and reducing data. I am also writing codes to implement these functionalities except for the data reduction pipeline part. All of these devices  ran without any problems even when the operating room's temperature went down below -10°C in the midnight. The softwares also ran happily, though I had fixed some minor bugs.

AST3-II in Mohe when it was snowing


However, the observation condition there was always horrible. Because of closed to the river and surrounding by forrest, the humidity was very high. We always found the air was filled with tiny ice crystals in the night. This factor degraded image qualities. Even such an average FWHM of stars on the image merely less than 4″ was a good  "seeing" there. Even worse, the cooler of the CCD did not work correctly. The temperature of the CCD was just in the same level of the environment's. It caused the "dark current" relative high. Therefore, the detected magnitude was very shallow, many faint source could not be revealed in such conditions.

In order to monitor weather condition in Dome A, we planned to build a new automated weather station(AWS) instead of the fallen one. I took a mini AWS to Mohe, too. It had a propeller anemometer, a barometer, a relative humidity/temperature sensor and three temperature sensors. These sensors also worked correctly.

automated weather station 

We also made several pages to show the real-time equipments status and the weather data. Click here to view these images and plots.