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The Nebula Beginning
The Nebula Beginning
The Nebula Beginning
M17
The Nebula Beginning
M1 – The Orion Nebula
The Nebula Beginning
OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC
CLOUD
This is a NASA Hubble Space Telescope image of the tattered debris of a star
that exploded 3,000 years ago as a supernova. This supernova remnant, called
N132D, lies 169,000 light-years away in the satellite galaxy, the Large
Magellanic Cloud.
A Hubble Wide Field Planetary Camera 2 image of the inner regions of the
supernova remnant shows the complex collisions that take place as fast moving
ejecta slam into cool, dense interstellar clouds. This level of detail in the
expanding filaments could only be seen previously in much closer supernova
remnants. Now, Hubble's capabilities extend the detailed study of supernovae
out to the distance of a neighboring galaxy.
Material thrown out from the interior of the exploded star at velocities of more
than four million miles per hour (2,000 kilometers per second) plows into
neighboring clouds to create luminescent shock fronts. The blue-green filaments
in the image correspond to oxygen-rich gas ejected from the core of the star.
The oxygen-rich filaments glow as they pass through a network of shock fronts
reflected off dense interstellar clouds that surrounded the exploded star. These
dense clouds, which appear as reddish filaments, also glow as the shock wave
from the supernova crushes and heats the clouds.
Supernova remnants provide a rare opportunity to observe directly the interiors
of stars far more massive than our Sun. The precursor star to this remnant,
which was located slightly below and left of center in the image, is estimated to
have been 25 times the mass of our Sun. These stars "cook" heavier elements
through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the
titanic supernova explosions scatter this material back into space where it is
used to create new generations of stars. This is the mechanism by which the
gas and dust that formed our solar system became enriched with the elements
that sustain life on this planet. Hubble spectroscopic observations will be used
to determine the exact chemical composition of this nuclear- processed
material, and thereby test theories of stellar evolution.
The image shows a region of the remnant 50 light-years across. The supernova
explosion should have been visible from Earth's southern hemisphere around
1,000 B.C., but there are no known historical records that chronicle what would
have appeared as a "new star" in the heavens.
This "true color" picture was made by superposing images taken on 9-10
August 1994 in three of the strongest optical emission lines: singly ionized sulfur
(red), doubly ionized oxygen (green), and singly ionized oxygen (blue).
Photo credit: Jon A. Morse (STScI) and NASA
The Nebula Beginning
STELLAR "EGGS" EMERGE FROM MOLECULAR CLOUD (Star-Birth
Clouds in M16)
This eerie, dark structure, resembling an imaginary sea serpent's head,
is a column of cool molecular hydrogen gas (two atoms of hydrogen in
each molecule) and dust that is an incubator for new stars. The stars
are embedded inside finger-like protrusions extending from the top of
the nebula. Each "fingertip" is somewhat larger than our own solar
system.
The pillar is slowly eroding away by the ultraviolet light from nearby hot
stars, a process called "photoevaporation". As it does, small globules of
especially dense gas buried within the cloud is uncovered. These
globules have been dubbed "EGGs" -- an acronym for "Evaporating
Gaseous Globules". The shadows of the EGGs protect gas behind
them, resulting in the finger-like structures at the top of the cloud.
Forming inside at least some of the EGGs are embryonic stars -- stars
that abruptly stop growing when the EGGs are uncovered and they are
separated from the larger reservoir of gas from which they were
drawing mass. Eventually the stars emerge, as the EGGs themselves
succumb to photoevaporation.
The stellar EGGS are found, appropriately enough, in the "Eagle
Nebula" (also called M16 -- the 16th object in Charles Messier's 18th
century catalog of "fuzzy" permanent objects in the sky), a nearby starforming region 7,000 light-years away in the constellation Serpens.
The picture was taken on April 1, 1995 with the Hubble Space
Telescope Wide Field and Planetary Camera 2. The color image is
constructed from three separate images taken in the light of emission
from different types of atoms. Red shows emission from singly-ionized
sulfur atoms. Green shows emission from hydrogen. Blue shows light
emitted by doubly- ionized oxygen atoms.
Credit: Jeff Hester and Paul Scowen (Arizona State University), and
NASA
The Nebula Beginning
GIANT STARBIRTH REGION IN NEIGHBORING GALAXY
This is a Hubble Space Telescope image (right) of a vast
nebula called NGC 604, which lies in the neighboring spiral
galaxy M33, located 2.7 million light-years away in the
constellation Triangulum.
This is a site where new stars are being born in a spiral arm
of the galaxy. Though such nebulae are common in galaxies,
this one is particularly large, nearly 1,500 light-years across.
The nebula is so vast it is easily seen in ground-based
telescopic images (left).
At the heart of NGC 604 are over 200 hot stars, much more
massive than our Sun (15 to 60 solar masses). They heat the
gaseous walls of the nebula making the gas flouresce. Their
light also highlights the nebula's three-dimensional shape, like
a lantern in a cavern. By studying the physical structure of a
giant nebula, astronomers may determine how clusters of
massive stars affect the evolution of the interstellar medium of
the galaxy. The nebula also yields clues to its star formation
history and will improve understanding of the starburst
process when a galaxy undergoes a "firestorm" of star
formation.
The image was taken on January 17, 1995 with Hubble's
Wide Field and Planetary Camera 2. Separate exposures
were taken in different colors of light to study the physical
properties of the hot gas (17,000 degrees Fahrenheit, 10,000
degrees Kelvin).
Credit: Hui Yang (University of Illinois), Jeff J. Hester
(University of Arizona) and NASA.
The Nebula Beginning
HUBBLE SNAPS "FAMILY PORTRAIT"
The Hubble Space Telescope's Near Infrared Camera and MultiObject Spectrometer (NICMOS) has peered into the Cone
Nebula, revealing a stunning image of six baby sun-like stars
surrounding their mother, a bright, massive star. Known as NGC
2264 IRS, the massive star triggered the creation of these baby
stars by releasing high-speed particles of dust and gas during its
formative years.
The image on the left, taken in visible light by a ground-based
telescope, shows the Cone Nebula, located 2,500 light-years
away in the constellation Monoceros. The white box pinpoints
the location of the star nursery. The nursery cannot be seen in
this image because dust and gas obscure it. The large cone of
cold molecular hydrogen and dust rising from the lefthand edge
of the image was created by the outflow from NGC 2264 IRS.
The NICMOS image on the right shows this massive star - the
brightest source in the region - and the stars formed by its
outflow. The baby stars are only .04 to .08 light-years away from
their brilliant mother.
The rings surrounding the massive star and the spikes
emanating from it are not part of the image. This pattern
demonstrates the near-perfect optical performance of NICMOS.
A near-perfect optical system should bend light from point-like
sources, such as NGC 2264 IRS, forming these diffraction
patterns of rings and spikes.
This false color image was taken with 1.1-, 1.6-, and 2.2-micron
filters.
The image was taken on April 28, 1997.
Credits: Rodger Thompson, Marcia Rieke and Glenn Schneider
(University of Arizona), and NASA
The Nebula Beginning
The Nebula Beginning
Ghostly Reflections in the Pleiades
STScI-PRC2000-36
NASA's Hubble Space Telescope has
caught the eerie, wispy tendrils of a
dark interstellar cloud being
destroyed by the passage of one of
the brightest stars in the Pleiades star
cluster. Like a flashlight beam shining
off the wall of a cave, the star is
reflecting light off the surface of pitch
black clouds of cold gas laced with
dust. These are called reflection
nebulae.
The Nebula Beginning
EDGE-ON PROTOPLANETARY DISK IN THE ORION
NEBULA
Resembling an interstellar Frisbee, this is a disk of dust seen
edge-on around a newborn star in the Orion nebula, located
1,500 light-years away. Because the disk is edge-on, the star
is largely hidden inside, in this striking Hubble Space
Telescope picture. The disk may be an embryonic planetary
system in the making. Our solar system probably formed out
of just such a disk 4.5 billion years ago. At 17 times the
diameter of our own solar system, this disk is the largest of
several recently discovered in the Orion nebula.
The left image is a three-color composite, taken in blue,
green, and red emission lines from glowing gas in the nebula.
The right image was taken through a different filter, which
blocks any bright spectral emission lines from the nebula, and
hence the disk itself is less distinctly silhouetted against the
background. However, clearly visible in this image are
nebulosities above and below the plane of the disk; these
betray the presence of the otherwise invisible central star,
which cannot be seen directly due to dust in the edge-on disk.
The images were taken between January 1994 and March
1995, and a study of their characteristics has been submitted
for publication to the Astronomical Journal.
Credit: Mark McCaughrean (Max-Planck-Institute for
Astronomy), C. Robert O'Dell (Rice University), and NASA
The Nebula Beginning
CLOSE-UP OF "PROPLYDS" IN ORION A
Hubble Space Telescope view of a small portion
of the Orion Nebula reveals five young stars. Four
of the stars are surrounded by gas and dust
trapped as the stars formed, but were left in orbit
about the star. These are possibly protoplanetary
disks, or "proplyds," that might evolve on to
agglomerate planets. The proplyds which are
closest to the hottest stars of the parent star
cluster are seen as bright objects, while the object
farthest from the hottest stars is seen as a dark
object. The field of view is only 0.14 light-years
across. The Orion Nebula star-birth region is
1,500 light-years away, in the direction of the
constellation Orion the Hunter.
The image was taken on 29 December 1993 with
the HST's Wide Field and Planetary Camera 2.
credit: C.R. O'Dell/Rice University NASA
The Nebula Beginning
WARPED DISK MAY INDICATE PRESENCE OF PLANET AROUND THE STAR BETA PICTORIS
This image from NASA's Hubble Space Telescope shows for the first time the inner region of a 200-billion mile diameter dust disk around the star Beta
Pictoris. This region has long been hidden from ground-based telescopes because of the glare from the central star. The disk is slightly warped. If the warp
were there when the star formed, it would long since have flattened out, unless it is produced and maintained by the gravitational pull of a planet. The
suspected planet would dwell inside a five-billion mile diameter clear zone inside the inner edge of the disk.
Top This is a visible light image of the disk, which appears spindle-like because it is tilted nearly edge-on to our view. The disk is made up of microscopic
dust grains of ices and silicate particles, and shines by reflected light from the star. This image indicates that the central clearing is occupied by one or more
planets which agglomerated out of the disk and then swept out smaller particles. The bright star, which lies at the center of the disk, is blocked out in this
image.
Bottom False-color is applied through image processing to accentuate details in the disk structure. Hubble reveals that the pink-white inner edge of the disk
is slightly tilted from the plane of the outer disk (red-yellow-green) as identified by a dotted line. A simple explanation is that a large planet is pulling on the
disk. It is not possible to see the planet directly because it is close to the star, and perhaps a billion-times fainter.
This image was taken with the Wide Field Planetary Camera 2 in January 1995. The star is located 50 light-years away in the southern constellation Pictor
(Painter's Easel). Beta Pictoris is a main sequence star, slightly hotter than our Sun.
Credit: Chris Burrows, Space Telescope Science Institute (STScI) the European Space Agency (ESA), J. Krist (STScI), the WFPC2 IDT team, and NASA