Atop a frigid Antarctic plateau

Au, it could offer the clearest view on Earth of the stars at night, according to new research by an international team from China, Australia and the University of British Columbia (UBC). The challenge? The location is one of the coldest and most remote places on Earth. The findings were published today in Nature.

“A telescope located in Dome A could outperform a similar telescope located anywhere else on the planet,” said UBC astronomer Paul Hickson, co-author of the study. “The combination of high altitude, low temperature, long periods of continuous darkness and an exceptionally stable atmosphere make Dome A a very attractive location for optical and infrared astronomy. A telescope located there would have sharper images and could detect fainter objects.” .

One of the biggest challenges in terrestrial astronomy is overcoming the effect of atmospheric turbulence on the image quality of the telescope. This turbulence causes the stars to flicker, and the measurement of their impact is known as ‘seeing’. The less turbulence (the lower the vision number), the better.

“The thinner boundary layer in Dome A makes it less difficult to locate a telescope above it, giving greater access to the free atmosphere,” said UBC astronomer Bin Ma, lead author of the paper.

Currently, the highest performing observatories are located at high altitude locations along the equator (Chile and Hawai’i) and offer views in the range of 0.6 to 0.8 arcseconds. Overall, Antarctica has the potential to see better, due to weaker turbulence in the free atmosphere, with an estimated range of 0.23 to 0.36 arcseconds in a place called Dome C.

Ma, Hickson, and their colleagues in China and Australia evaluated a different location, Dome A, also known as Dome Argus. Dome A is located near the center of East Antarctica, 1,200 kilometers inland.

The researchers estimated that the location has a thinner boundary layer (the lowest part of the atmosphere, which is influenced by friction from the Earth’s surface) than Dome C. Previous measurements of Dome A have been taken during the day, but the authors report a median. Night vision of 0.31 arcseconds, reaching as low as 0.13 arcseconds.

Measurements at Dome A, taken at a height of eight meters, were much better than those at the same height at Dome C and comparable to those at a height of 20 meters at Dome C.

Not surprisingly, the researchers’ team’s viewing capabilities are also hampered by frost: Overcoming this problem could improve vision by 10 to 12 percent. But the site is promising, according to Ma.

“Our telescope observed the sky fully automatically at an unmanned station in Antarctica for seven months, with the air temperature dropping to -75 ° C sometimes. In itself, that’s a technological advance.”