GALLERY u JUROMENHA FORTRESS Sérgio Conceição Stars appear to circle above the Church of the Misericórdia, located inside a medieval fortress in Juromenha, Portugal. DETAILS: Canon EOS 5D Mark III DSLR camera with 14-mm lens. Stack of 270 exposures each totaling 30 seconds at f/3.5, ISO 1600. q PROPELLER NEBULA Emil Andronic Simeis 57, commonly known as the Propeller Nebula, is a bright area in a much larger cloud of ionized gas in northern Cygnus. DETAILS: TS Optics 65-mm APO refractor with ZWO ASI294MC Pro and QHY5L-II cameras. Stack of 160 exposures totaling 111/2 hours through Antlia Hα and IDAS LPS-D2 filters. 76 SEPTEMBER 2021 * SKY & TELESCOPE