Optical Sky Brightness and Transparency during the Winter Season at Dome A Antarctica from the Gattini-All-Sky Camera

Abstract

The summit of the Antarctic plateau, Dome A, is proving to be an excellent site for optical, near-infrared, and terahertz astronomical observations. Gattini is a wide-field camera installed on the PLATO instrument module as part of the Chinese-led traverse to Dome A in 2009 January. We present here the measurements of sky brightness with the Gattini ultra-large field of view ( ´ 90 90 ) in the photometric B-, V-, and R-bands; cloud cover statistics measured during the 2009 winter season; and an estimate of the sky transparency. A cumulative probability distribution indicates that the darkest 10% of the nights at Dome A have sky brightness of S B =22.98, S V =21.86, and S R =21.68 mag arcsec −2 . These values were obtained during the year 2009 with minimum aurora, and they are comparable to the faintest sky brightness at Maunakea and the best sites of northern Chile. Since every filter includes strong auroral lines that effectively contaminate the sky brightness measurements, for instruments working around the auroral lines, either with custom filters or with high spectral resolution instruments, these values could be easily obtained on a more routine basis. In addition, we present example light curves for bright targets to emphasize the unprecedented observational window function available from this ground-based site. These light curves will be published in a future paper.

Using all-sky differential photometry to investigate how nocturnal clouds darken the night sky in rural areas

“…For decades, NSB monitoring was mainly of interest for astronomers as they were first to study light pollution 19–22 . For logical reasons, astronomers mainly concentrated their research on clear skies, but also performed comprehensive observations at several important (often very remote) astronomical sites, for example at high altitudes 23–25 or latitudes 26 . The advent of small photometers customized for NSB measurements (mainly the Sky Quality Meter: SQM) has sparked NSB research beyond professional astronomy.…”

Optical observations of LIGO source GW 170817 by the Antarctic Survey Telescopes at Dome A, Antarctica

“…The entire observatory is controlled remotely using the Iridium satellite system to transmit operational commands. Dome A is a site with the lowest temperature and the lowest absolute humidity on earth [34,36,37,38]. The weather conditions are suitable for taking data for over 95% of the time during the winter.…”

“…Its unique location allows for continuous observations lasting longer than 24 hours during the austral winter. The continuous time coverage is important for many applications of time-domain astronomy (e.g., [32], [33] and [34]). It is equipped with a 10K×10K CCD camera in frame transfer mode that provides a field of view of 4.14 deg 2 [35].…”

Astronomy from Dome A in Antarctica

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