the-telescope-times:

In Rotating Galaxies normal matter precisely determines acceleration

A new radial acceleration relation found among spiral and irregular
galaxies challenges current understanding – and possibly existence – of
dark matter.

In the late 1970s, astronomers Vera Rubin and Albert Bosma independently
found that spiral galaxies rotate at a nearly constant speed: the
velocity of stars and gas inside a galaxy does not decrease with radius,
as one would expect from Newton’s laws and the distribution of visible
matter, but remains approximately constant. Such ‘flat rotation curves’
are generally attributed to invisible, dark matter surrounding galaxies
and providing additional gravitational attraction.

Now a team led by Case Western Reserve University researchers has found a
significant new relationship in spiral and irregular galaxies: the
acceleration observed in rotation curves tightly correlates with the
gravitational acceleration expected from the visible mass only.

Read more ~ SpaceDaily