Gallery ▶ TRANSIT IN A NEW LIGHT Howard Eskildsen Mercury's 7½-hour-long transit tested the patience of observers. This sequence, from 11:15:23 to 18:38:30 UT, shows the Sun as it appears at a wavelength of 393.4 nm (the Ca-K line). Details: Orion ED80 apochromatic refractor, Lunt B600 filter module, and DMK 21AU04.AS video camera. Colorized stack of sixteen 12-second images. ▾ CL ASSIC SPIRAL John Vermette Staring at us face-on from 21 million light-years away in Ursa Major, the Pinwheel Galaxy (M101) nearly matches the full Moon's apparent size. Details: Hyperion 12.5-inch astrograph, SBIG STL-11000M CCD camera, and LRGB filters. Total exposure: 5.3 hours. ▾▶ BRIGHT AND EASY Bob and Janice Fera A treat when spotted in even small telescopes, Messier 81 (Bode's Galaxy) is a 7th-magnitude gem in Ursa Major. The supermassive black hole in its core has a mass of 70 million Suns. Details: PlaneWave CDK17 astrograph and Apogee AltaU16M CCD camera used with Astrodon LRGB filters. Total exposure: 12.7 hours. 76 September 2016 sky & telescope