Southeastern Knot
The southeastern knot is located at J2000 RA 20h 56m 21.2s Dec +30° 23′ 59″ on the southeastern rim of the Cygnus Loop. The knot has been identified as an encounter between the blast wave from the supernova and a small isolated cloud. The knot is a prominent X-ray feature, consisting of a number of filaments correlated with visual line emission. By combining visual and X-ray data, it can be shown that the southeastern knot is an indentation on the surface of the blast wave, not a small cloud but the tip of a larger cloud. The presence of a reverse shock is evidence that the knot represents an early stage of a blast wave encountering a large cloud.
External images | |
---|---|
Cygnus Loop compared to the Moon |
Read more about this topic: Cygnus Loop
Famous quotes containing the word knot:
“Not the less does nature continue to fill the heart of youth with suggestions of his enthusiasm, and there are now men,if indeed I can speak in the plural number,more exactly, I will say, I have just been conversing with one man, to whom no weight of adverse experience will make it for a moment appear impossible, that thousands of human beings might exercise towards each other the grandest and simplest of sentiments, as well as a knot of friends, or a pair of lovers.”
—Ralph Waldo Emerson (18031882)