Explanation:
What's lighting up the Cigar Galaxy?
M82, as this
irregular galaxy is also known, was stirred up by a
recent pass near large
spiral galaxy
M81.
This doesn't fully explain the source of the
red-glowing outwardly expanding gas, however.
Recent evidence indicates that this gas
is being driven out by the combined emerging
particle winds of many stars, together creating a
galactic "superwind."
The
above photographic mosaic, released yesterday to commemorate the
sixteenth anniversary of the
Hubble Space Telescope,
highlights a specific color of red light strongly emitted by ionized
hydrogen gas, showing detailed filaments of this gas.
The filaments extend for over 10,000
light years.
The 12-million light-year distant
Cigar Galaxy is the
brightest galaxy in the sky in infrared light, and can be seen in visible light with a small
telescope
towards the constellation of
Ursa Major.