Free Floating Planets In Orion
Explanation:
This false-colour image
of the young Trapezium star cluster in the Orion
Nebula was made with an
infrared camera at wavelengths about
twice as long as visible light.
The
infrared data are part of a sensitive survey
of this nearby star forming region in which
astronomers
have identified over 100 extremely low mass
objects -- candidates for
elusive brown dwarf stars.
Brown dwarfs are failed
stars with masses so low (about 8% of the Sun's)
that they can not sustain nuclear hydrogen burning, a sun-like star's main
energy source.
While brown dwarfs are thought to be still massive enough to burn
deuterium for energy,
thirteen of the low mass objects show evidence of
lying below even the deuterium burning limit
(about 1.3% of the
Sun's mass) falling in a range
more commensurate with giant planets.
These drifting, "free-floating planets" are perhaps as little as 8
times as massive as
Jupiter and likely formed along with the cluster stars
a million or so years ago.
They are detectable in the infrared because they
are still hot from formation, but will eventually cool and fade.
If the
Trapezium is typical of young
star clusters, then
the survey results suggest that brown dwarfs
and free-floating planets may be fairly common, but there
are not enough to solve the mystery
of dark
matter in the Universe.
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.
