Locality (astronomy)

Locality in astronomy is in theory closeness of the observer relative to the observed astronomical phenomenon under consideration, and thus in practice the relative closeness of the phenomenon to the star system of the Sun.
Being local is an ambiguous condition, and always relative to the order of magnitude of the relevant phenomenon. The term "local" is commonly applied to structures on five successively larger scales beyond the roughly two-light-years diameter of the Solar System: 