O and Na abundance patterns in open clusters of the Galactic disk

O vi in the local interstellar medium

O/IR Polarimetry for the 2010 Decade (GAN): Science at the Edge, Sharp Tools for All

O18O and C18O observations of rho Oph A

OB Stars & Stellar Bowshocks in Cygnus-X: A Novel Laboratory Estimating Stellar Mass Loss Rates

OB Stars in Stochastic Regimes

Observability of pulsar beam bending by the Sgr~A* black hole

Observable consequences of kinetic and thermal AGN feedback in elliptical galaxies and galaxy clusters

Observable Signatures of EMRI Black Hole Binaries Embedded in Thin Accretion Disks

Observation of the Far-ultraviolet Continuum Background with SPEAR/FIMS

Observational Constraints on Submillimeter Dust Opacity

Observational Constraints on Superbubble X-ray Energy Budgets

Observational Determination of the Turbulent Ambipolar Diffusion Scale and Magnetic Field Strength in Molecular Clouds

Observational evidence for the shrinking of bright maser spots

Observational Evidence from SDSS for a Merger Origin of the Milky Way's Thick Disk

Observational Identification of First Cores: Non-LTE Radiative Transfer Simulation

Observational Properties of Rotationally Excited Molecular Hydrogen In Translucent Lines of Sight

Observational Properties of the Metal-Poor Thick Disk of the Milky Way Galaxy and Insights into Its Origins

Observational properties of the open cluster system of the Milky Way and what they tell us about our Galaxy

Observational studies of pre-stellar cores and infrared dark clouds