In a few years astrometry with the venerable combination of Hubble Space Telescope and Fine Guidance Sensor will be replaced by SIM, GAIA, and long-baseline interferometry. Until then we remain a resource of choice for sub-millisecond of arc precision optical astrometry. As examples we discuss 1) the uses which can be made of our parallaxes of galactic Cepheids, and 2) the determination of pert...

We present distances to 76 medium-sized molecular clouds and an extra large-scale one in the second Galactic quadrant ($104.75^\circ <l<150.25^\circ $ $|b|<5.25^\circ$), 73 of which are accurately measured for first time. Molecular cloud samples drawn from $l$-$b$-$V$ space ($-95 < V_{\rm LSR}< 25$ \kms) with density-based spatial clustering applications noise (DBSCAN) algorithm, background-eli...

Due to sharp depth transition, big holes may be found in the novel view that is synthesized by depth-image-based rendering (DIBR). A hole-filling method based on disparity map is proposed. One important aspect of the method is that the disparity map of destination image is used for hole-filling, instead of the depth image of reference image. Firstly, the big hole detection based on disparity ma...

Recently we have been able to achieve parallaxes and proper motions with accuracies approaching microarcseconds using the VLBA. The apparent proper motion of Sgr A* has been measured with extremely high accuracy, strongly constraining Θ0/R0 and potentially offering a new dynamical definition of the Galactic plane. The intrinsic motion of Sgr A* perpendicular to the Galactic plane is extremely s...

Model atmosphere analyses of échelle spectra of some fifty nearby Fand G-type stars are presented. The sample is confined to the main-sequence, turnoff and subgiant region, regardless of the metal abundance. On the base of these data, spectroscopic parallaxes are calculated and compared to the Hipparcos astrometry to explore the reliability of the derived stellar parameters, notably the surface...