Auroral contribution to sky brightness for optical astronomy

• Main Authors: J. T. Dempsey, J. W. V. Storey, A. Phillips
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: antarctica — optical spectra; sky brightness; aurora; South Pole; Antarctic; The Antarctic; Antarc*; Antarctica; Geomagnetic Pole; polar night; South pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.71.2710; http://www.phys.unsw.edu.au/~mgb/Antbib/spa7.pdf

The Antarctic Plateau holds great promise for optical astronomy. One relatively unstudied feature of the polar night sky for optical astronomical observing is the potential contamination of observations by aurorae. In this study we analyse auroral measurements at South Pole Station and show that during an average winter season, the B band sky brightness is below 21.9 B magnitudes per square arcsecond for 50 % of the observing time. In V band, the median sky brightness contribution is 20.8 magnitudes per square arcsecond during an average winter. South Pole Station is situated within the auroral zone and experiences strong and frequent auroral activity. The Antarctic locations of Dome C and Dome A are closer to the geomagnetic pole where auroral activity is greatly reduced compared with that of South Pole Station. Calculations based on satellite measurements of electron flux above the Antarctic Plateau are used to show that at Dome C, the contribution to sky background in the B and V bands is up to 3.1 magnitudes less than that at the South Pole. The use of notch filters to reduce the contribution from the strongest auroral emission lines and bands is also discussed. The scientific potential of an Extremely Large Telescope (ELT) located at Dome C is discussed, with reference to the effect that auroral emissions would have on particular astronomical observations.