Night Skies Data Report: Photometric Assessment of Night Sky Quality at Cape Lookout National Seashore, 2013

White, Kelsey

doi:10.36967/2315506

This report characterizes night sky conditions in Cape Lookout National Seashore (CALO) using measurements made in the park unit and models of regional conditions based on satellite data. Calibrated night sky imagery was obtained to characterize the night sky at three sites. These ground-based observations were collected on October 28 and October 30, 2013. Satellite data from 2013 and 2024 were used to create maps of predicted night sky conditions in and around the park. The night sky brightness over CALO varies with site location. The two darker sites average to a sky brightness that is 0.68 times brighter than natural sky conditions, indicating slightly degraded sky quality. The third site is 6 times brighter than natural sky conditions, suggesting that the natural night sky conditions are not readily visible. We estimate more than 94% of naked eye stars remained visible under the measured sky brightness at the two darker sites and 42% at the brighter site. With these results, the two darker sites provide an excellent opportunity to view the natural night sky from the park during a cloudless moonless night. Based on the visibility of astronomical objects in CALO, we classified the sky as Bortle Class 5 (suburban sky). The sky overhead is influenced by moderate light pollution with an average zenith brightness of 21.27 mag/arcsec2. The average naked eye limiting magnitude (NELM) is 6.2, which is approaching degraded sky quality. Our Sky Quality Meter (SQM) measurements averaged 21.04 mag/arcsec2. The main influences on CALO’s night sky quality, ordered by predicted brightness of light domes, were from Atlantic, Morehead City, Havelock, Beaufort, Jacksonville, Davis, New Bern, Virginia Beach, Raleigh, and Greenville.

Night Skies Data Report: Photometric Assessment of Night Sky Quality at Cape Lookout National Seashore, 2013

Series

Collections