First Daytime Near-infrared Photometric Observations at Antarctic Dome A
Year: 2025
Type: article
Abstract: Located at the highest point on the Antarctic Plateau’s ice sheet, Dome A is generally believed to be one of the best places on Earth for nighttime astronomy in the optical and near-infrared (NIR) bands. Daytime optical/NIR site characteristics are yet to be quantified, however. Here we report the first daytime observations of bright stars at the J band during the austral summer of 2023/2024. The experiments were conducted using a 150 mm telescope with a field of view of 0 . ° 87 × 0 . ° 69 and a pixel size of 2 . ″ 5. The sky brightness at zenith was measured to be ∼5.2 mag arcsec−2 at noon when the solar elevation was ∼27°, and it slightly darkened to ∼5.8 mag arcsec−2 at midnight with a solar elevation angle of ∼10°. Stars as faint as J = 10.06 mag were significantly detected at 5σ levels with an effective exposure time of 175 s around midnight. The pathfinding experiments indicate that a sensitivity ∼2 mag deeper can be reached by the planned 1 m class telescopes, taking advantage of the small free atmosphere seeing. Considering the high latitude and the extremely high fraction of clear days at this site, valuable bright transients with J ≲ 12 mag, such as (super)novae in the local universe and space debris at low orbits, within ∼1/4 of the whole sky around the south celestial pole can be timely discovered and continuously monitored throughout the year.
Source: The Astronomical Journal
Authors: Chenwei Yang, Tuo Ji, Zhengyang Li, Jiannan Cong, Chao Chen, Michael C. B. Ashley, Zhixu Wu, Haimeng Li, Yuhan Luo, Liang Xi, Yipeng Zhou, Yaqi Zhao, Xingyu Zhou, Lei Hao, Zhongping Zhang, Hongyan Zhou, Peng Jiang
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W4408840639