Dome A in Antarctica is the best site for optical astronomical observation on Earth

August 03, 2020

A research team led by Prof. SHANG Zhaohui from National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) has proved that Dome A in Antarctica is the best site for optical astronomical observation on Earth. The study was published in Nature on July 29.

Seeing reflects the atmospheric turbulence that makes stars twinkle or smears star images observed by telescopes. At an observatory with good seeing, weak turbulence results in a smaller seeing value and sharper images. This is especially good for viewing faint objects. A small-aperture telescope at such a site can compete with a larger one at other sites.

Due to the geographic and atmospheric properties at Dome A, atmosphere turbulence usually resides in the near-ground, shallow boundary layer, above which is the very stable free atmosphere with superb seeing.

The researchers reported a seeing measurement as good as 0.13 arcseconds and a median free-atmosphere seeing of 0.31 arcseconds, measured with instruments on an 8-m-high tower.

Currently, the best telescopes are located at good sites in Hawaii and Northern Chile, with seeing in the range of 0.6 to 0.8 arcseconds. It is clear that Dome A has the potential to host a good astronomical observatory.

In addition, the median boundary layer thickness is about 14m at Dome A, compared to 30m at Dome C in Antarctica, making Dome A more feasible and cost-efficient for future construction.

Dome A is the highest place on the polar ice cap, with an altitude of 4093m. Kunlun Station is the only station there, but has not yet been developed into a winterover station. Therefore, the team had to design and build unattended instruments to cope with temperatures as low as -80? and frosting problems.

The research team developed the instrument KL-DIMM independently, and participated in the 35th Chinese National Antarctic Research Expedition (CHINARE) in November 2018 to the inland Kunlun Station. Two redundant KL-DIMMs started to take data in January 2019. They worked fully automatically through winter and obtained precious nighttime seeing measurement data.

Dome A was first visited by humans in January 2005 via overland traverse from Zhongshan Station by the 21st CHINARE. CHINARE is managed and carried out by the Chinese Arctic and Antarctic Administration (CAA) and the Polar Research Institute of China (PRIC), and has consistently supported the astronomy program at Dome A.

The combination of high altitude, low temperature, long periods of continuous darkness, and an exceptionally stable superb seeing makes Dome A a very attractive location for optical and infrared astronomy.
-end-


Chinese Academy of Sciences Headquarters

Related Antarctica Articles from Brightsurf:

Ice loss likely to continue in Antarctica
A new international study led by Monash University climate scientists has revealed that ice loss in Antarctica persisted for many centuries after it was initiated and is expected to continue.

Antarctica: cracks in the ice
In recent years, the Pine Island Glacier and the Thwaites Glacier on West-Antarctica have been undergoing rapid changes, with potentially major consequences for rising sea levels.

Equatorial winds ripple down to Antarctica
A CIRES-led team has uncovered a critical connection between winds at Earth's equator and atmospheric waves 6,000 miles away at the South Pole.

Antarctica more widely impacted by humans than previously thought
Using a data set of 2.7 million human activity records, the team showed just how extensive human use of Antarctica has been over the last 200 years

Antarctica more widely impacted than previously thought
Researchers at Australia's Monash University, using a data set of 2.7 million human activity records, have shown just how extensive human use of Antarctica has been over the last 200 years.

Predicting non-native invasions in Antarctica
A new study identifies the non-native species most likely to invade the Antarctic Peninsula region over the next decade.

Persistent drizzle at sub-zero temps in Antarctica
When the temperature drops below freezing, snow and ice are expected to follow.

Human 'footprint' on Antarctica measured for first time
The full extent of the human 'footprint' on Antarctica has been revealed for the first time by new IMAS-led research which used satellite images to measure stations, huts, runways, waste sites and tourist camps at 158 locations.

Iguana-sized dinosaur cousin discovered in Antarctica
Scientists have discovered the fossils of an iguana-sized reptile, which they named 'Antarctic king,' that lived at the South Pole 250 million years ago (it used to be warmer).

Scientists drill to record depths in West Antarctica
A team of scientists and engineers has for the first time successfully drilled over two kilometres through the ice sheet in West Antarctica using hot water.

Read More: Antarctica News and Antarctica Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.