The Whirlpool Galaxy is perhaps
the most striking example of a spiral galaxy.
NASA's Great Observatories have studied the galaxy
at infrared, visible, and X-ray wavelengths.
Different wavelength observations
reveal different structures in the galaxy.
In three dimensions,
the galaxies spiral arms whirl through
a pancake-shaped disk.
Visible light shows older, yellower stars near the center
and younger, bluer stars along the spiral arms.
Infrared light uncovers the oldest and reddest stars
that populate the entire galactic disk.
X-rays reveal the energetic emission
from binary star systems
that include neutron stars or black holes.
Along the dark, dust lanes,
bright pink nebulae are the birthplaces of new stars.
Before leaving these stellar nurseries,
the most massive stars die in supernova explosions,
which heat the surrounding gas to X-ray temperatures.
At much cooler temperatures,
the infrared glow from gas and dust
exposes the detailed structure underlying the spiral arms.
The core of the galaxy contains
a supermassive black hole ...
... whose gravitational energy
powers bright X-ray emission.
Cool infrared dust outlines
the hot gas in star-forming regions ...
... where dense clouds collapse
and the next generation of stars bursts forth.
The Whirlpool Galaxy
reveals different characteristics
in different wavelengths.
The contrasting features seen in multi-wavelength studies
greatly enhance our understanding of galactic structure.