Night Skies Data Report: Photometric Assessment of Night Sky Quality at Great Smoky Mountains National Park, 2008
White KC . 2025. Night Skies Data Report: Photometric Assessment of Night Sky Quality at Great Smoky Mountains National Park, 2008. Science Report. NPS/SR—2025/354. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/2315505
This report characterizes night sky conditions in Great Smoky Mountains National Park (GRSM) 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 two sites. These ground-based observations were collected on October 26 and October 29, 2008. Satellite data from 2024 were used to create a map of predicted night sky conditions in and around the park. The sky overhead is influenced by moderate light pollution with an average zenith brightness of 20.95 mag/arcsec2, about 1.5 times brighter than average natural conditions. We estimate more than 52% naked eye stars remained visible under the measured sky brightness, providing opportunities to partially view the natural night sky from the park during a cloudless moonless night. The whole sky over GRSM is between 2.49 and 4.5 times brighter than average natural levels, indicating moderately degraded natural night sky conditions on average. Based on the visibility of astronomical objects in GRSM, we classified the sky at Cades Cove as Bortle Class 4 (rural/suburban transition) and Kuwohi as Bortle Class 5 (suburban sky). The average naked eye limiting magnitude (NELM) is 6.7, which is approaching near pristine under average conditions. The main influences on GRSM’s night sky quality, ordered by predicted brightness of light domes, were from Knoxville, Gatlinburg, Sevierville, Maryville, Pigeon Forge, Bryson City, Asheville, Cherokee, Seymour, and Charlotte.
- Type
- Published Report
- Authors
- White, Kelsey
- Date of Issue
- 2025-09
- Publisher
- National Park Service
- DOI
- 10.36967/2315505
- Units
- GRSM , NRSS , NSNN
- Keywords
- brightness, GRSM, light pollution, night skies, night sky, photometric assessment, sky quality