Nebulosity in Sagittarius
Credit & Copyright: D. Malin (AAO),
AATB
Explanation:
What causes the colors in this beautiful nebulosity in
Sagittarius?
Dubbed NGC 6589 and NGC 6590,
the colors of this nebulosity,
are caused by gas and
dust.
The blue color of the nebula nearest the bright stars is caused by
reflection off interstellar dust. The
dust emits little visible
light of its own - in the absence of a nearby star the dust would appear
dark, blocking light from
background stars. The red color of the
nebula farthest from the bright stars is caused by glowing hydrogen gas.
Energetic light
from the central stars ionizes
hydrogen gas - which glows red when recombining with a local
electron.
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.
