I loves me some astronomical nebulae! And the Wide-field Infrared Survey Explorer – WISE – can really deliver:
[Click to emblossom.]
This image shows AFGL 3193 – what looks like a rosebud – a small piece of a very complicated region of gas, dust, and stars in the constellation of Cepheus in the northern sky. This region has star formation, cold and hot dust, and even a supernova remnant (called NGC 7822). This particular part seen by WISE shows a cluster of young stars called Berkeley 59 – the stars colored blue to the right – surrounded by the gas and dust from which they formed. This cluster is less than a million years old, and the massive, hot stars are blasting out radiation that is eating away at the cocoon surrounding them.
In the false-color image from WISE, red shows the coolest dust, blue and cyan warmer material, and green reveals long-chain organic molecules called polycyclic aromatic hydrocarbons, or PAHs. You can see how the PAHs appear to form around the rim of the nebula as the material there is compressed and warmed by the ultraviolet light and solar winds from the young stars. The filaments are testament to the forces tossed around as the stars go through their violent birth process. One of the stars in the cluster is a massive O5 star with dozens of times the mass of the Sun, and blasting out radiation at a rate 100,000 times that of the Sun!
I’m not sure just how big an area this image covers, but it’s roughly a degree across, twice the width of the Moon on the sky. The cluster is located about 3000 light years away, which is good: a lot of those stars will soon (well, in a few million years) explode, and this distance is far enough away that we’ll see a spectacular light show, but won’t wind up hurting us. Phew!
WISE is designed to survey the sky in infrared, literally spinning around and scanning the entire celestial sphere. It doesn’t have a field of view per se; the data come down in a stream and the astronomers on the ground can put them together at any scale they want, a little bit like Google maps. So expect to see lots more images of objects like this one, and you can get the whole list at the WISE gallery.
Image credit: NASA/JPL-Caltech/WISE Team