Advertisers in This Issue Astronomy equipment manufacturers and dealers are a valuable resource for amateur and professional astronomers alike. Patronize our advertisers in this issue and enjoy all the benefits of their expertise. Product Locator Astro-Physics, Inc. » page 81 telescopes / mounts astro-physics.com Atik Cameras » page 1 cameras atik-cameras.com Celestron » page 5 binoculars / eyepieces / mounts / telescopes celestron.com Diffraction Limited » page 40 cameras diffractionlimited.com Explore Scientific » page 3 binoculars / eyepieces / mounts / telescopes explorescientific.com iOptron » page 40 mounts / telescopes ioptron.com Sky-Watcher » inside front cover binoculars / mounts / telescopes skywatcherusa.com Software Bisque » page 13 + back cover mounts bisque.com Stellarvue » inside back cover eyepieces / telescopes stellarvue.com Ad Index AAVSO ..................................................... 75 American Astronomical Society ................ 83 Arizona Sky Village Portal ......................... 81 Astro-Physics, Inc. ................................... 81 Atik Cameras ............................................. 1 Bob's Knobs ............................................. 80 Casitas de Gila Guesthouses .................... 81 Celestron ................................................... 5 Diffraction Limited ................................... 40 Explore Scientific ....................................... 3 iOptron .................................................... 40 Knightware .............................................. 81 Lunatico Astronomia ................................ 80 New Mexico Skies Astronomy Enclave ..... 81 NexDome ................................................. 80 Nine Planets Ring .................................... 81 PreciseParts ............................................ 80 Princeton University Press........................ 75 Revolution Imager .................................... 80 Sky & Telescope ...........................71, 75, 79 Sky-Watcher ............................................ C2 Software Bisque ................................ 13, C4 Star-Hop Maker .......................................81 Stellarvue ................................................ C3 Technical Innovations ............................... 80 TravelQuest.............................................. 81 Yearbook of Astronomy ............................ 79 To advertise in our Product Locator, please contact Tim Allen at 773-551-0397, or email him at Ads@skyandtelescope.org 82 NOVEMBER 2021 * SKY & TELESCOPEhttp://www.astro-physics.com http://www.ioptron.com http://www.atik-cameras.com http://www.skywatcherusa.com http://www.celestron.com http://www.bisque.com http://www.diffractionlimited.com http://www.stellarvue.com http://www.explorescientific.com