Star Tracks of Piscis Austrinus above the Castle of Sesimbra
October 17, 2010
The image above showing the tracks of stars in the constellation Piscis Austrinus ("Southern Fish") was captured above the Moorish Castle of Sesimbra, near Lisbon, Portugal, on February 10, 2010. This medieval fortress is more than 900 years old. It stands 787 feet (240 m) above the water and is very well preserved.
Recording the tracks of the fainter stars against the intense light pollution caused by illumination of the Castle walls was quite challenging. With the naked eye, I could only distinguish Fomalhaut ('"mouth of the fish"), the brightest star of Piscis Austrinus, having a magnitude of 1.15. However, the other stars of this star grouping are very faint and near the limit of the human naked eye detection for city locations. Click on image for star magnitudes.
Photo details: Camera Maker: Canon; Camera Model: Canon EOS 50D; Lens: EF50mm f/1.8 II; Focal Length: 50.0mm; Aperture: f/4.0; ISO equiv: 800; Exposure Bias: none; Metering Mode: Matrix; Exposure: Manual; Exposure Mode: Manual; White Balance: Auto; Flash Fired: No (Manual). Exposure of 30 seconds for each frame; sum of 199 images taken on February 10, 2010 between 12:30 and 2:17 a.m.; total time integration of one hour and 40 minutes.