In the winter of 2018, the star track taken with a mobile phone at point C of Saishiten, the starry sky left a beautiful trajectory during the rotation of the earth.
Photo courtesy of Deng Licai
China News Service, Beijing, August 18 (Reporter Sun Zifa) The monitoring data lasted for 3 years showed that the research team of the National Astronomical Observatory of the Chinese Academy of Sciences selected the site at the 4200-meter elevation point (Zaishiten C area) in the Saishiten mountain area of Lenghu Lake, Qinghai. The optical observation conditions, comprehensively measured in terms of visibility, infrared observation, number of clear nights, background brightness of clear nights, and weather, can be compared to the world's first-class large observatories.
This important discovery of the international first-class optical astronomical observatory site in Lenghu, Qinghai, will not only break the bottleneck that has restricted the development of optical astronomy in China for a long time, it will also bring new major opportunities for the development of optical astronomy in China, and will also change all current international excellent optical astronomical observatories. They are all located in the western hemisphere, and fill the gap of the world's large optical telescopes in the geographical longitude region of the Qinghai-Tibet Plateau, providing extremely valuable strategic scarce resources for the development of international optical astronomy.
The Qinghai Lenghu Optical Observatory site selection and monitoring major scientific progress papers recently completed by the research team of Deng Licai of the National Astronomical Observatory of the Chinese Academy of Sciences were published online in the internationally renowned academic journal "Nature" on the night of August 18, Beijing time.
On December 20, 2020, Lenghu Saishiteng began to shine, confirming that good natural seeing can be realized on the telescope in the full-open dome.
Photo courtesy of Tian Cairang
According to the National Astronomical Observatory of the Chinese Academy of Sciences, for a long time, the Chinese astronomy community has attached great importance to the site selection of optical astronomical observatories.
In 2017, Deng Licai's research team worked closely with the local government of Lenghu, Haixi Prefecture, Qinghai Province, to start a site search in the uninhabited area of western Haixi Prefecture.
According to historical records of very good weather conditions in the Lenghu area, such as abundant sunshine, extremely low precipitation, and clear night sky, the research team inspected the Lenghu Saishiteng mountain area on the spot, and determined to conduct a fixed site selection in Saishiteng C area.
In the winter of 2020, the whole observatory is shrouded in the afterglow of the setting sun, and the vast Qaidam Basin is in the distance.
Photo courtesy of Deng Licai
Since mid-January 2018, Deng Licai's research team has formally continuously monitored the number of clear nights, the background brightness of clear nights, and the weather in Area C of Saishiten.
Through the continuous efforts of the team, in May of that year, the initial infrastructure was built at the monitoring point of the Saishiten C area, and 95% continuous coverage of all parameters was achieved, and conclusive data on the optical/infrared observation conditions of Saishitenshan were obtained.
Researcher Deng Licai said that in order to prevent various non-scientific factors from interfering with the site selection of large-scale astronomical observation facilities, and to ensure the reliability and fairness of the data, all the raw data collected by the Lenghu Site Monitoring Project will be disclosed in real time throughout the site selection process.
As of the end of 2020, the main monitoring data of the Lenghu site has accumulated for 3 years. The research team's detailed statistical analysis shows that the median seeing of Lenghu Saishiteng Mountain C area (at an elevation of 4200 meters) is 0.75 arcsec This parameter is roughly the same as the same period data of the best international sites, and is better than other sites. In terms of infrared observation conditions, it is the most important site index for extreme scientific targets such as "origin of matter" and "origin of life". It is a sinkable precipitation vapor, and the Lenghu Saishiteng site is the most superior among all the international first-class sites in the middle geographical latitude. According to the comprehensive quantitative analysis based on observable time and seeing degree, the quality of Lenghu Saishiteng Mountain is better than that of the Qinghai-Tibet Plateau. The other locations are basically the same as the currently internationally recognized best optical astronomical observatories in the Atacama region of northern Chile and the Monakaya Peak in Hawaii, which are located at the same mid-latitude of the earth.
In the early winter of 2018, Deng Licai was on his way to climb the Lenghu Saishiten Mountain for an inspection.
Photo by Tian Cairang
It is understood that Lenghu Town is located in Haixi Prefecture, Qinghai Province, in the geographical hinterland of China. The town area is only 2700 meters above sea level and 80 kilometers away from the site of Saishiteng Mountain. It can build a reliable logistics support and scientific research base.
As a future large-scale astronomical observatory site, the Lenghu Saishiten C-area observation base has good traffic guarantee and obvious location advantages.
The comprehensive support provided by the Haixi Prefecture Government of Qinghai Province has also provided important guarantees for the timely start and stable operation of the Lenghu Observatory.
The Chinese Academy of Sciences and the Qinghai Provincial Government will cooperate as soon as possible to protect the resources of the Lenghu Observatory, avoid the impact of lights and other human activities, and plan and arrange the development of major astronomical observation facilities in the future to maximize the scientific potential of the Lenghu Observatory. .
At the same time, we will promote the international cooperation and opening of the Lenghu Observatory site, attracting international leading astronomical observation facilities to settle down, making Lenghu an important base for international optical astronomy research and an important source for humans to explore the mysteries of the universe and cultivate original scientific achievements.
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