VISTA's First Light
Jul
01, 2010
A new telescope designed to see
objects in visible and infrared
light has just come online.
The Visible and Infrared Survey
Telescope for Astronomy (VISTA)
began operations a day after its
December 11, 2009 dedication
ceremony. NGC 2024, otherwise known
as the Flame Nebula, was among those
objects recorded during its first
light.
The Flame Nebula is located in
the constellation of Orion, just
below the three visible stars that
make up its belt. Of the three stars
that comprise Orion's sword, one of
them is actually the
Orion Nebula, a celestial
object that has been the subject of
past Picture of the Day articles.
Both the Flame and Orion nebulae are
part of the Orion Molecular Cloud
complex that also includes the
Horsehead Nebula, the
Barnard-30 star-forming
region,
M43,
and
M78.
Normally, the Flame Nebula is
obscured by an opaque cloud of dust.
However,
VISTA's supercooled
infrared detection apparatus (frozen
at - 200º C) can "see through" the
cloud, because it is sensitive to
the infrared light being emitted by
warmer gases and dust behind the
dark veil. High resolution
images confirm that the
nebula is similar in structure to
others that have been identified in
these pages as electrically active
phenomena.
What is a nebula?
Consensus opinions state that a
star in the latter stages of its
evolution will experience violent
upheavals as its supply of hydrogen
fuel diminishes and the "ash" of
heavier elements accumulates in its
core. Before the star reaches its
final white dwarf stage, it is
thought that the disequilibrium
induced by the fusion of those
heavier nuclei causes the dying star
to eject vast quantities of
matter—effectively "sloughing off"
its outer layers. It is this
expanding cloud of dust and gas,
illuminated by the senescent star at
its center, that astronomers detect.
The name "planetary nebula" was
assigned to the glowing formations
early in the days of telescopic
observation. They appeared to be
round, with a faint greenish tinge,
looking similar to Uranus, so it was
assumed that they might also be gas
giant planets.
Planetary nebulae come in all
shapes and sizes: round, elliptical,
interlocking rings, or nested
cylinders. They often exhibit long
tendrils, symmetrical hourglass
shapes, and bubbles within their
structures. According to
conventional theories, those
features are the result of shock
waves, or stellar winds blowing off
the parent star, crashing into the
slower material ahead of them.
In the case of the Flame Nebula,
the unmistakeable appearance of
twisting Birkeland current filaments
is clearly visible bisecting the
center of the image. The
overall configuration is an
hourglass, not a sphere, and the
shapes within the nebula correspond
to the filaments, helices, and
pillars that electrical discharge in
plasmas create.
In the laboratory, plasma forms
cells separated by thin walls of
opposite charge called double
layers. Could separation of charges
also take place in nebulae? That
question might require centuries to
answer, since the only way to detect
a double layer in space is by flying
a probe through one. However,
everywhere in our own Solar System
cellular structures separated by
double layers abound: the Sun's
heliosphere, comet tails, and
magnetospheres are all examples of
charge separation in plasma.
Although no definitive answers
are yet forthcoming, Electric
Universe advocates assume that
plasma will behave in the same way
whether in the laboratory, or in a
formation like the Flame Nebula.
Electric double layers resulting
from charge separation in space
prompted Nobel laureate
Hannes Alfvén to suggest that
they be considered their own class
of celestial object. If that were
so, the mysteries that confound
astronomy today would become
substantially less quixotic.
Stephen Smith