Shell Game in NGC 300
Explanation:
Featured in color in
yesterday's episode,
big, beautiful, face-on spiral galaxy
NGC 300 is seen here through
a narrow filter that transmits only the red
light of hydrogen atoms.
Ionized by energetic starlight, a hydrogen atom emits
the characteristic red
H-alpha
light as its single electron
is recaptured and
transitions to lower energy states.
As a result, this image of
NGC 300
is dominated by regions filled with
massive, young stars and
shell-shaped clouds of
hydrogen gas hundreds to thousands of light-years across.
Formed in groups called
OB associations, the stars are likely only
a few million years
young.
The hydrogen clouds are glowing
nebulae or
HII regions that have been sculpted
by the strong stellar winds and ultraviolet radiation.
While picking out your
favorite cosmic shell in this picture,
don't be misled by the relatively bright foreground stars
located in our own Milky Way galaxy.
They often show
spikes
and rings caused by the telescope and camera system.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
