O 2/O 3 Microatmospheres in the Surface of Ganymede
O 7774 A diagnostic for quiescent prominences
O a comet near the South Pole
O a new period of eclipses
O a remarkable phenomenon that occurs in total and annular eclipses of the sun
O a singular appearance during the solar eclipse, Nov. 1826
O a small variable star in Serpens
O acoplamento mecânico entre a antena e o transdutor no detector de ondas gravitacionais Mario Schenberg
O algebraic notation
O ambiente de binárias de pequena massa em formação: o caso do glóbulo cometário CG30 e IRAS08076-3556
O an ancient Eclipse observed in China
O AN Apparent Displacement of the Meridian as a Function of the Lunar Hour Angle
O and Mg abundances in metal-poor halo stars and their implications for stellar Fe yields
O and Na abundance patterns in open clusters of the Galactic disk
O and Ne in an H-He Fast Solar Wind
O and Ne K absorption edge structures and interstellar abundance towards Cyg X-2
O and Wolf-Rayet Stars as X-Ray Sources
O and α-Element Abundances in Metal-Poor Stars
O Andromedae
O Andromedae