M51: The Whirlpool Galaxy in Dust and Stars
The Whirlpool Galaxy is a classic spiral galaxy.
At only 30 million
light years distant and fully 60
thousand light years across,
M51, also known as
NGC 5194,
is one of the brightest and most
picturesque galaxies on the sky.
The above image is a digital combination
of a ground-based image from the
0.9-meter telescope at
Kitt Peak National Observatory and a space-based image from the
Hubble Space Telescope highlighting sharp features normally
too red to be seen.
Anyone with a good pair of
binoculars, however,
can see this
Whirlpool toward the constellation of
Canes Venatici.
M51 is a
spiral galaxy of type Sc and is the dominant member of a
whole group of galaxies.
Astronomers speculate that M51's
spiral structure is
primarily due to its
gravitational interaction with a
smaller galaxy just off the top of this image.