On the velocity dispersion in the core of the globular cluster M15

On the vertical structure of dilute planetary rings

On the X-ray spectrum of Kepler's supernova remnant

Operator perturbation method for multi-level line transfer with partial redistribution

Optical luminosity functions for compact groups of galaxies

Optical spectra and semi-empirical model of a white-light flare

Optimal acceleration of a spacecraft with an electroreactive engine in the case of constrained velocity of rotation of the thrust vector

Optimal acceleration of spacecraft with electroreactive engine for bounded rate of rotation of thrust vector

Optimal low-thrust interplanetary orbit transfer including Earth escape spiral trajectory

Optimal low-thrust limited power transfer between neighbouring quasi-circular orbits of small inclinations around an oblate planet

Optimal reentry trajectories of a lifting vehicle

Optimal solar sail planetocentric trajectories

Optimally Tuned Iterative Reconstruction Algorithms for Compressed Sensing

Optimization of low-thrust transfers in the three body problem

Optimizing polynomials for floating-point implementation

Orbital Evolution of Centaurs

Orbital evolution of distant artificial earth satellites

Orbital stability of planar oscillations of a satellite in a circular orbit

Orbital tests of relativistic gravity using artificial satellites

Orbital uncertainties of single-apparition asteroids