M63: The Sunflower Galaxy from Hubble
From NASA’s Astronomy Picture of the Day
One of the bright spiral
galaxies visible in the north sky is M63, the Sunflower Galaxy.
M63, also catalogued as
NGC 5055, can be found with a small telescope toward the constellation of Hunting Dogs (Canes Venatici).
The featured picture from
the Hubble Space Telescope exhibits the center of M63, complete with long
winding spiral arms glowing blue from a few bright young stars, emission nebulae glowing
red from hot ionized hydrogen gas, and dark dust in numerous filaments.
Light takes about 35 million years to reach
us from M63, and about 60,000 years to cross the spiral galaxy.
Stars in the outer
regions of the Sunflower
Galaxy rotate about the center at a speed
so high that, given the matter seen and assuming
normal gravity, they should fly off into space.
The fact that the stars
remain indicates the
presence of sort of invisible, gravitationally-binding, dark
matter.
