Cygnus Loop

Cygnus Loop

An emission nebula in the constellation Cygnus. The Veil nebula (NGC 6960, 6990, 6995) forms part of the Cygnus Loop. It is the supernova remnant of a star that exploded probably some 50 000 years ago. The remnant now has an area of about 3 square degrees and is about 800 parsecs away. Its rate of expansion has gradually slowed to its present 100 km s–1 as the expanding shell collides with and sweeps up any surrounding interstellar matter. This creates a shock wave that compresses, heats, and ionizes the gas atoms, which then become visible as the emission nebula.

Cygnus loop

[′sig·nəs ‚lüp]
(astronomy)
A supernova remnant about 17,000 years old, and 30-40 parsecs across and probably about 770 parsecs distant that emits radio waves and x-rays as well as visible light. Also known as Veil Nebula.
References in periodicals archive ?
This is an ultraviolet image of the Cygnus Loop Nebula that is situated about 1,500 miles away from Earth.
During the summer months with Cygnus high in the sky, it's an ideal time to view one of the finest such objects, known as the Cygnus Loop or perhaps more commonly the Veil Nebula.
Images taken by the unrepaired Hubble Space Telescope had revealed such a pattern for the Cygnus Loop, a supernova remnant 2,500 light-years from Earth (SN: 3/13/93, p.
Arranged in a broken shell some 3[degrees] across, these arcs are collectively known as the Cygnus Loop or Veil Nebula.
And among the remnants of these explosions, the Cygnus Loop - a broken, brightly lit ring measuring 137 light-years across - stands out as a prime target for observers.
Moreover, radio observations of the entire Cygnus Loop suggest that it may consist of two interacting remnants from two separate supernovae centuries apart.
Another Milky Way mystery revolves around a 15,000-year-old supernova remnant called the Cygnus Loop.
Recently published studies detail the dynamics of ionized oxygen in the filaments of the Cygnus Loop supernova remnant and the discovery of absorption lines from highly excited molecular hydrogen in the Dumbbell Nebula.
Astronomers working with HUT have also calculated the speed of a shock wave plowing through interstellar space from the Cygnus Loop, a supernova remnant about 26,000 light-years from Earth.
A shock wave of expanding gas from the supernova burst created the Veil Nebula and the rest of the luminous Cygnus Loop, and you can tell the explosion has swept some dust under the carpet.
In 1992 Jeff Hester (Arizona State University) and his colleagues pointed Hubble at a shocked filament in the Veil Nebula, or Cygnus Loop, the expanding remnant of a star that exploded some 15,000 years ago about 2,500 light-years away.