NGC 1999: Reflection Nebula In Orion
Credit & Copyright: Hubble Heritage Team
(STScI) and
NASA
Explanation:
A dusty
bright nebula
contrasts dramatically with a dusty dark nebula in
this Hubble Space Telescope image recorded shortly
after December's orbital
servicing mission.
The nebula, cataloged as
NGC 1999, is a
reflection nebula,
which shines by reflecting light from
a nearby star.
Unlike emission nebulae, whose
reddish glow comes from
excited atoms of gas, reflection nebulae have a
bluish cast
as their interstellar dust
grains preferentially reflect blue
starlight.
While perhaps the most famous reflection nebulae surround
the bright young stars of
the Pleiades
star cluster,
NGC 1999's stellar illumination is provided by the embedded variable star
V380
Orionis, seen here just left of center.
Extending right of center, the
ominous
dark nebula is actually a condensation of cold molecular
gas and dust so thick and dense that it blocks light.
From our perspective it lies in front of the bright
nebula, silhouetted against the ghostly nebular glow.
New stars will likely form within
the dark cloud, called a
Bok globule,
as self-gravity continues to compress its dense gas and dust.
Reflection nebula
NGC 1999
lies about 1500 light-years away in the constellation
Orion,
just south of Orion's well known emission nebula,
M42.
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.
