The familiar winter sky constellation Orion takes on a
spectacular guise in the infrared, as seen in this false-color
image constructed from data collected by IRAS--the Infrared
Astronomical Satellite. This picture, covering about 30 degrees x
24 degrees is a composite of IRAS wavelength band data
centered at 12 microns, 60 microns, and 100 microns. New processing techniques
have been used to enhance faint details and remove the
instrumental artifacts (stripes) seen in earlier IRAS images.
The warmest features, e.g.~the stars, are brightest at 12 microns.
This emission is coded blue. The interstellar dust is
cooler and shines brighter at 60 microns (coded green) and 100 microns
(coded red).
The bright yellow region in the lower right of the
enlarged image is
the Sword of Orion, containing the Great Orion Nebula (M42 and
M43). Above it to the left is the nebulosity around the belt
star Zeta Orionis which contains the often photographed
Horsehead Nebula (barely visible as a small indentation on the
right side). Higher and to the left is M78, a reflection
nebula. The Rosette Nebula is the brightest object near the
left margin of the picture.
Most of the visually bright stars of Orion are not prominent in
the infrared. However, Betelgeuse can be easily seen in the
upper center of the picture as a blue-white dot (the faint tail
is an instrumental artifact). The large ring to the right of
Betelgeuse is the remnant of a supernova explosion, centered
around the star Lambda Orionis. These rings are quite common in
the IRAS sky. Another one, fainter and larger, can be seen in
the lower left quadrant of the image.
Image credits:
Infrared Processing and Analysis Center, Caltech/JPL