6650 Meteors and Shooting Stars. General. 



6700 Connection between Comets and Meteors. 



6720 Zodiacal Light, (reg-eiischeiu, etc. 



6800 Spectroscopy of Moon, Planets, Comets, Zodiacal 



Light, Terrestrial Atmosphere (Aurora, Meteors). 

 6810 Mouu. General. 



Atmosphere. 



Study of Surface. 



Motion. 

 6820 Planets. (Each separately). 



General. 



Atmo^^phere. 



Study of Surface. 



Motion. 



Rotation. 

 6920 Comets. General. 



Wavelengths. 



Chemistry. 



Motion. 

 6940 Zodiacal Light. 



6950 Meteors. 



6960 Terrestrial Atmosphex'e, Aurora, Telluiic lines, (see 



also 4580, 5400). 



STELLAR UNIVERSE. 



7000 General. 



7010 Fixed Stars. 



7020 Oliservations of position. 



7030 Catalogues of position. 



General. 



Fundamental. 



Zone. 



Special (e.<j., Heliometer Stars. 



Stars for Photographic Chart). 

 7050 Comparison and Discussion of Catalogues of position. 



7060 Proper motion. 



7070 Parallax. 



7080 Magnitude. 



Photometric Catalogues. 

 7120 Colour (integrated light). 



Colour Catalo.i^-ues. e.g. Red Stars. 

 Spectrum. (SeeSOOOu 

 7140 Radiation (Bolometry). {See a/so C 4200). 



7150 Stellar Diameters. 



7160 Distribution in heavens. 



7500 Double Stars and Multiple Stars. 

 7510 Observations. 



