binary star


Splitting Hairs (and Stars)

When we talk about the distance between stars there are 2 very different measures that might apply.  The actual distance between any two stars (typically measured in light-years, or astronomical units [the distance between Earth and our Sun] if they are very close) is generally not apparent by simple observation, whether aided by a telescope or not.  But we might also be concerned with the angular separation between stars.  Frankly, this information is most useful in measuring the quality of various optical elements, including human eyes. Many stars are actually “binary stars” that are relatively close to each other in […]