NGC 281

NGC 281 from Chandra.jpg
NGC 281 is a bustling hub of star formation about 10,000 light years away. This composite image of optical and X-ray emission includes regions where new stars are forming and older regions containing stars about 3 million years old.

The optical data (seen in red, orange, and yellow) show a small open cluster of stars, large lanes of obscuring gas and dust, and dense knots where stars may still be forming. The X-ray data (purple), based on a Chandra observation lasting more than a day, shows a different view. More than 300 individual X-ray sources are seen, most of them associated with IC 1590, the central cluster. The edge-on aspect of NGC 281 allows scientists to study the effects of powerful X-rays on the gas in the region, the raw material for star formation.

A second group of X-ray sources is seen on either side of a dense molecular cloud, known as NGC 281 West, a cool cloud of dust grains and gas, much of which is in the form of molecules. The bulk of the sources around the molecular cloud are coincident with emission from polycyclic aromatic hydrocarbons, a family of organic molecules containing carbon and hydrogen. There also appears to be cool diffuse gas associated with IC 1590 that extends toward NGC 281 West. The X-ray spectrum of this region shows that the gas is a few million degrees and contains significant amounts of magnesium, sulfur and silicon. The presence of these elements suggests that supernova recently went off in that area.

NGC 281HSTFull.jpg
Bok globules in the NGC 281 nebula (IC 1590 cluster).

NGC281NBHunterWilson.jpg
Autor/Urheber: Hewholooks, Lizenz: CC BY-SA 3.0
NGC281 - Pacman Nebula in Hubble Palette Narrowband from amateur equipment

Pacman and Friends.png
Autor/Urheber: Judy Schmidt from Fresh Meadows, NY, USA, Lizenz: CC BY 2.0

More infrared astronomy from WISE. Once again, I've reversed the wavelength order for what I consider a more aesthetically pleasing result, so keep in mind that deep blue is the longer wavelength and red is the shorter wavelength.

The Pacman Nebula, otherwise known as NGC 281, is revealed not as a singular pool of light but as a larger structure of seemingly related knots and trails of dust. Pacman itself is the largest blue structure northeast of center. The two other noticeable structures do not have any special designations.

In the lower right corner of the image is a blueish strand of stars I included because it seemed interesting. Deep blue in this case corresponds to the warm dust in the 22 micron channel. In visible light, a knot of dark, obscuring dust is visible in the location of the strand, but no stars are. If I had to guess I would say they stars in the process of forming. They just happen to be in a line like this instead of clustered into more of a blob. I couldn't find any literature on this particular structure, but star forming regions are ubiquitous throughout the Milky Way. What does seem unusual is their isolation and apparently long, linear shape. I haven't spent nearly enough time studying infrared imagery to say whether it is common or uncommon, though. Is this what a stellar nursery looks like before they begin to blow away their natal dust cloud?

I tried very hard to balance the colors this time and not have the blue and red overwhelm the image, so more cyan is showing through this time, unlike with the Pleiades image. Nine WISE frames were aligned and matched to create a smooth mosaic. Some small optical artifacts were removed. No sharpening or color saturation was done.

Red: W1 (3.4 μm) Yellow-Green: W2 (4.6 μm) Cyan: W3 (12 μm) Blue: W4 (22 μm)

North is up.