'Pacman Nebula' Lives the High Life

High-mass stars are important because they are responsible for much of the energy pumped into our galaxy over its lifetime.

Unfortunately, these stars are poorly understood because they are often found relatively far away and can be obscured by gas and dust.

The star cluster NGC 281 is an exception to this rule.

It is located about 9,200 light years from Earth and, remarkably, almost 1,000 light years above the plane of the Galaxy, giving astronomers a nearly unfettered view of the star formation within it.

NGC 281 is known informally as the "Pacman Nebula" because of its appearance in optical images. In optical images the "mouth" of the Pacman character appears dark because of obscuration by dust and gas, but in the infrared Spitzer image the dust in this region glows brightly.

Image Credits: X-ray: NASA/CXC/CfA/S.Wolk; IR: NASA/JPL/CfA/S.Wolk

NASA Video of Orion nebula

The Orion Nebula is a huge cluster of gas and dust 1350 light years away from Earth. It's been dubbed a "stellar nursery" because huge stars are formed there.

In the video above, you can watch a wide view of the constellation of Orion, then zoom in through Orion's sword.The clip ends with a new image of the nebula itself, revealed in intricate detail.

This image won seventh place in a recent photo competition run by the European Southern Observatory (ESO) and is a composite of exposures through five different filters.

The competition invited amateurs to trawl through the observatory's raw data to find beautiful images that had been overlooked by professionals. It was transformed into a colour image by overall winner Ivor Chekalin. A gallery of his images can be seen here.

The image was captured with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory, Chile.

NASA WISE Image: Orion Molecular Cloud and the Flame Nebula

This mosaic image taken by NASA's Wide-field Infrared Survey Explorer, or WISE, features three nebulae that are part of the giant Orion Molecular Cloud; the Flame nebula, the Horsehead nebula and NGC 2023.

Despite its name, there is no fire roaring in the Flame nebula.

What makes this nebula shine is the bright blue star seen to the right of the central cloud.

This star, Alnitak, is the easternmost star in Orion's belt.

Wind and radiation from Alnitak blasts away electrons from the gas in the Flame nebula, causing it to become ionized and glow in visible light. The infrared glow seen by WISE is from dust warmed by Alnitak's radiation.

The famous Horsehead nebula appears in this image as a faint bump on the lower right side of the vertical dust ridge. In visible light, this nebula is easily recognizable as a dramatic silhouette in the shape of a horse's head.

It is classified as a dark nebula because the dense cloud blocks out the visible light of the glowing gas behind it. WISE's infrared detectors can peer into the cloud to see the glow of the dust itself.

A third nebula, NGC 2023, can be seen as a bright circle in the lower half of the image. NGC 2023 is classified as a reflection nebula, meaning that the dust is reflecting the visible light of nearby stars. But here WISE sees the infrared glow of the warmed dust itself.

Color in this image represents specific infrared wavelengths. Blue represents light emitted at 3.4-micron wavelengths, mainly from hot stars. Relatively cooler objects, such as the dust of the nebulae, appear green and red. Green represents 4.6-micron light and red represents 12-micron light.

This image was made from data collected after WISE began to run out of its supply of solid hydrogen cryogen in August 2010. Cryogen is a coolant used to make infrared detectors more sensitive.

WISE mapped the entire sky by July using four infrared detectors, but during the period from August to October 2010, while the cryogen was depleting, WISE had only three detectors operational, and the 12-micron detector was less sensitive.

This turned out to be a good thing in the case of this image, because the less-sensitive detector reduced the glare of the Flame portion of the nebula enough to bring out details of the rest of the nebula.

Image Credit: NASA/JPL-Caltech/UCLA

Orion nebula

The Orion nebula is about 1350 light years from Earth. This infrared image, taken by VISTA, shows young stars deep in the nebula, which are obscured by dust when observed with visible light.

This image, a composite of 10-minute exposures taken at different wavelengths in the near-infrared part of the spectrum, covers a region of sky about 1 by 1.5 degrees.

(Image: ESO/J. Emerson/VISTA; acknowledgment: Cambridge Astronomical Survey Unit)

The Sword and The Rose

The Sword and The Rose (Orion's Sword and M42) by Marcus Davies. 10 January 2010. Lying just south of the three stars that form Orion's belt, Orion's sword contains the Great Orion Nebula. This hotbed of star formation lies about 1350 light years away, making it the brightest and closest star forming region to Earth