Popular Astronomy, Volume 50

absolute magnitude American American Astronomical Society American Meteor Society angle appeared Astronomical Society atmosphere average azimuth changes College comets constellation craters Cygni diameter direction distance earth eclipse end point ephemeris errors fireball galactic galaxies given height horizon indicated instruments July June Jupiter latitude Lick Observatory light curve longitude luminosity lunar Mare Imbrium Mars maxima maximum mean measured meridian meteor meteorite method miles minimum moon motion nebulae Notes novae object observations Observatory obtained OCCULTATIONS Ohio orbit paper parallax path perihelion phenomena photographs planet POPULAR ASTRONOMY position predicted present probably problem projectile radiation region reports rotation seen solar spectra spectral type spectrum SS Cygni stellar sunspot surface Table telescope tion train University Variable Star variation velocity Venus visible Yerkes Observatory zenith Zodiacal Light