The Horsehead Nebula, it is embedded in the vast and complex Orion Nebula. The dark molecular cloud, roughly 1,500 light years distant, is cataloged as Barnard 33 and is visible only because its obscuring dust is silhouetted against the bright emission nebula IC 434. The bright blue reflection nebula NGC 2023 is visible on the lower left. The prominent horse head portion of the nebula is really just part of a larger cloud of dust which can be seen extending toward the bottom of the picture.
The dust is so thick in the center of NGC 1333 that you can hardly see the stars forming. Conversely, the very dust clouds that hide the stars also reflects their optical light, giving NGC 1333's predominantly blue glow the general designation of a reflection nebula. A highly detailed image of the nebula, shown above, was taken recently by the Mayall 4-meter telescope on Kitt Peak in Arizona, USA and released to honor astronomer Stephen Strom on his retirement.
Bright gas and dark dust permeate the space between stars in the center of a nebula known as NGC 6559. The gas, primarily hydrogen, gives the diffuse red glow of the emission nebula. As energetic light from neighboring stars ionizes interstellar hydrogen, protons and electrons recombine to emit light of very specific colors, including the red hue observed. Small dust particles reflect blue starlight efficiently and so creates the blue reflection nebulosity seen near two of the bright stars.
Los energéticos procesos de formación de estrellas crean no sólo los colores sino también el caos. El gas rojo brillante es resultado de la luz estelar de alta energía chocando con el gas hidrógeno interestelar. Los oscuros dust filamentos que dibuja M20 se crearon en las atmósferas frias de estrellas gigantes y en los desechos de la explosión de supernovas.
The Great Nebula in Orion is one of the most interesting of all astronomical nebulae known. Here fifteen pictures from the Hubble Space Telescope have been merged to show the great expanse and diverse nature of the nebula. In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries. These nurseries contain hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds.
To the right of the North America Nebula, cataloged as NGC 7000, is a less luminous Pelican Nebula. The two emission nebula measure about 50 light-years across, are located about 1500 light-years away, and are separated by a dark absorption cloud. The nebulae can be seen with binoculars from a dark location. Look for a small nebular patch north-east of bright star Deneb in the constellation of Cygnus. It is still unknown which star or stars ionize the red-glowing hydrogen gas.
It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula. Nicknamed the Eight-Burst Nebula and the Southern Ring Nebula, the gas originated in the outer layers of a star. In this picture, the hot blue pool of light seen surrounding this binary system is energized by the hot surface of the faint star. Although photographed to explore unusual symmetries, it's the asymmetries that help make this planetary nebula so intriguing.
In our neighboring galaxy the LMC. Were 30 Doradus at the distance of the Orion Nebula -- a local star forming region -- it would take up fully half the sky. Also called the Tarantula Nebula, the red gas indicates a massive emission nebula, although supernova remnants and dark nebula also exist in 30 Doradus. The bright knot of stars just below center is called R136 and contains many of the most massive, hottest, and brightest stars known.
Here's part of the Dumbbell Nebula that you can't see through binoculars. Pictured above is the central part of the Dumbbell Nebula, also known as M27 and NGC 6853. The Dumbbell is a planetary nebula created by the aging bright star visible just right of center. The nebula, located in the constellation Vulpecula, is thousands of years old. Visible in this false-color photograph is glowing hydrogen gas (green) and enigmatical globules of dense molecular gas and dust (red).
Infrared radiation from the well-studied Helix Nebula (NGC 7293) a mere 700 light-years away in the constellation Aquarius. The two light-year diameter shroud of dust and gas around a central white dwarf has long been considered an excellent example of a planetary nebula, representing the final stages in the evolution of a sun-like star. But the Spitzer data show the nebula's central star itself is immersed in a bright infrared glow. Models suggest the glow is produced by a dust debris disk.
In the depths of the dark clouds of dust and molecular gas known as M17, stars continue to form. The similarity to the Greek letter capital Omega gives the molecular cloud its popular name, but the nebula is also known as the Swan Nebula, the Horseshoe Nebula, and M17. The darkness of these clouds results from background starlight being absorbed by thick carbon-based smoke-sized dust. As bright massive stars form, they produce intense and energetic light that slowly boils away the dark shroud.
The Rosette Nebula (also known as Caldwell 49) is a large, circular H II region located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter.