Poster Version
Large Magellanic Cloud
This vibrant image from NASA's Spitzer Space Telescope shows the Large
Magellanic Cloud, a satellite galaxy to our own Milky Way galaxy.
The infrared image, a mosaic of 300,000 individual tiles, offers
astronomers a unique chance to study the lifecycle of stars and dust in a
single galaxy. Nearly one million objects are revealed for the first time
in this Spitzer view, which represents about a 1,000-fold improvement in
sensitivity over previous space-based missions. Most of the new objects
are dusty stars of various ages populating the Large Magellanic Cloud; the
rest are thought to be background galaxies.
The blue color in the picture, seen most prominently in the central bar,
represents starlight from older stars. The chaotic, bright regions outside
this bar are filled with hot, massive stars buried in thick blankets of
dust. The red color around these bright regions is from dust heated by
stars, while the red dots scattered throughout the picture are either
dusty, old stars or more distant galaxies. The greenish clouds contain
cooler interstellar gas and molecular-sized dust grains illuminated by
ambient starlight.
Astronomers say this image allows them to quantify the process by which
space dust -- the same stuff that makes up planets and even people -- is
recycled in a galaxy. The picture shows dust at its three main cosmic
hangouts: around the young stars, where it is being consumed (red-tinted,
bright clouds); scattered about in the space between stars (greenish
clouds); and in expelled shells of material from old stars
(randomly-spaced red dots).
The Large Magellanic Cloud, located 160,000 light-years from Earth, is one
of a handful of dwarf galaxies that orbit our own Milky Way. It is
approximately one-third as wide as the Milky Way, and, if it could be seen
in its entirety, would cover the same amount of sky as a grid of about 480
full moons. About one-third of the entire galaxy can be seen in the
Spitzer image.
This picture is a composite of infrared light captured by Spitzer. Light
with wavelengths of 3.6 (blue) and 8 (green) microns was captured by the
telescope's infrared array camera; 24-micron light (red) was detected by
the multiband imaging photometer.
