Researchers reveal early results in sky-brightness measurements in Antarctica

A analysis crew led by the researcher Wang Jian from the College of Science and Know-how of China (USTC), collaborating with the Polar Analysis Institute of China, developed the Close to-Infrared Sky Brightness Monitor (NISBM) for measurements at DOME A. Their work was printed in Month-to-month Notices of the Royal Astronomical Society (MNRAS) on March 21.

The Antarctic, with its unparalleled local weather and geographical situations, is taken into account to be the very best candidate for observing infrared bands on Earth. Regardless of the acute situations of low temperature, excessive altitude, low stress, and energy difficulties of Dome A in Antarctica, Wang’s crew accomplished the NISBM for Dome A in 2018 with the benefit of InGaAs detector in J, H, and Ks bands.

Researchers rigorously analyzed the preliminary Antarctic observations obtained by NISBM for Dome A and concluded that when the solar altitude angle decreases to a particular inflection level, the background depth of the sky on this band will not be influenced by the sun. By calculating and analyzing the zenith angle knowledge, the sky background depth of Antarctic Dome A in J, H, and Ks bands are 600 ~ 1100 μJ_y arcsec^-2, 1100 ~ 2600 μJ_y arcsec^-2, 200~900 μJ_y arcsec^-2, respectively.

In contrast with the stations at low latitudes and high altitudes, DOME A has a considerably decrease brightness within the Ks band, which is similar to the South Pole. This means that DOME A is a superb web site for Ks-band astronomical observations.