Published data for large amplitude asymptotic giant branch variables in the Large Magellanic Cloud are re-analysed to establish the constants for an infrared (K) periodluminosity relation of the form: MK = ρ[logP − 2.38]+ δ. A slope of ρ = −3.51± 0.20 and a zero point of δ = −7.15 ± 0.06 are found for oxygen-rich Miras (if a distance modulus of 18.39 ± 0.05 is used for the LMC). Assuming this s...

We develop the formalism for estimating parallaxes, proper motions and positions from long-focus astrometric observations as well as additional extraneous reference material whenever this is available and relax the constraints on the star parameters (basically their sums and correlations with the coordinates on the frames), thus generating (albeit correlated) quasiobservations whose inclusion w...

by far, many stereo-matching techniques have been successfully proposed and applied in digital aerial photogrammetry. however, due to some problems such as large parallaxes, occlusions, geometric deformations, and repetitive patterns in convergent close range images, these methods may not be applicable to the same level of success as that of aerial imagery. in order to overcome these shortcomin...

The parallaxes of eight galactic X-ray sources measured by Hipparcos are consistent with zero in all but two cases, 4U1145-619 (= Cen X-5) and HZ43. The parallax and proper motion measured for each of the others, including the Be/neutron star binaries X Per and A0535+26 and the massive X-ray binaries 4U0900-40, 4U1700-37, and Cyg XR-1, are consistent with their spectroscopic parallaxes. These r...

We present results from the PARallaxes of Southern Extremely Cool objects (PARSEC) program, an observational program begun in April 2007 to determine parallaxes for 122 L and 28 T southern hemisphere dwarfs using the Wide Field Imager on the ESO 2.2m telescope. The results presented here include parallaxes of 10 targets from observations over 18 months and a first version proper motion catalog....