Parallax is the observed displacement of an object caused by the change of the observer's point of view. In astronomy, it is an irreplaceable tool for calculating distances of far away stars. When you ...

IN this school-book of three hundred and twenty-six pages the authors have arranged a course on trigonometry which should be most useful to those studying this subject for the first time. The book may ...

Distance measured out to the far side of our Milky Way means that radio astronomers now can work on producing an accurate map of the full extent of our galaxy's structure for the first time.