ABSTRACT Recent advances have made ground‐based relative astrometry accurate to 100 microarcseconds (μas) or better a possibility. An important systematic effect on such measurements is the refraction ...

Direct detection and spectroscopy of exoplanets requires high-contrast imaging. For habitable exoplanets in particular, located at a small angular separation from the host star, it is crucial to ...

THE Astronomer Royal, in his last communication to the Royal Astronomical Society on the Transits of Venus, adverted to the injurious effect on the observations, which might possibly arise from the ...

The Global Positioning System could be used as a global thermometer and used to monitor climate change, say UK meteorologists. The idea rests on a relatively new technique for taking atmospheric ...