But verifying that assumption was difficult, given how crowded the region is, which makes it difficult to examine individual star motions
Astronomers develop theories of star motions
to not only understand how the stars in our galaxy are moving today but also how our galaxy formed and evolves.
Using telescopes that detect radio waves to penetrate the dust and gas, as well as optical telescopes to study star motions
, astronomers have mapped the Milky Way.
act as tracers to probe the gravitational signature of all mass, regardless of its nature.
And while she talks about her tough work-outs in all weathers, the star motions
a flunky to fetch a cardigan from her room because she thinks the temperature in the luxury hotel has dropped a little.
A precise measurement of star motions
in giant clusters can yield insights into how stellar groupings formed in the early universe, and whether an "intermediate mass" black hole, one roughly 10,000 times as massive as our Sun, might be lurking among the stars.
(The first 25 percent had been key-punched for the work done by Lacroute and Valbousquet at Strasbourg.) The second problem was creating the global reference star catalog that Herget and Corbin had proved would work, since all existing catalogs suffered either from insufficient stars or inadequately precise star motions
. Between 1989 and 1991 the authors combined over 150 catalogs to compute accurate positions and proper motions for more than 300,000 stars.
sometimes suggest that certain stars are revolving in binary systems.