Popular Astronomy, Volume 45

absolute magnitude altitude amateur Ambrose Swasey angle appearance appulse April asteroids Astronomical Society belt bright California camera catalogue changes clouds College color comet computed constellation Coronae craters Cygni dark Decl diameter distance earth east eclipse ephemeris Figure fireball fulgurite galactic geocentric Harvard height heliocentric heliocentric velocities hour angle indicate interest iron irregular variables Island July June Jupiter latitude light curve lines longitude luminosity lunar magnitude Mars maximum mean meeting meridian meteor meteorites miles moon motion nebulae night Nininger Notes Nova object observations Observatory orbit Orionids parallax parsecs path penumbral period Perseids photographic Pickering planet planetary plates polar POPULAR ASTRONOMY position present Professor reflector region reported right ascension sand-craters seen solar spectra spectrum SS Cygni stellar stone surface Swasey telescope theory tion University variable stars variation visible visual Yerkes Observatory