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 ?
Some of the arcs captured by NICER came from the Cygnus Loop, which is the remaining cosmic structure that was formed due to a (https://www.ibtimes.com/extremely-rare-zombie-stars-get-resurrected-could-go-supernova-soon-2795243) supernova that occurred thousands of years ago.
It's a supernova remnant, its arcs and shreds of radiance forming the roughly 3[degrees]-wide Cygnus Loop. The easiest section of the Loop to find is NGC 6960, the Veil Nebula.
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.168).
This is an ultraviolet image of the Cygnus Loop Nebula that is situated about 1,500 miles away from Earth.
The entire complex is often called the Cygnus Loop. It's a supernova remnant--the leftovers from a star that exploded thousands of years ago.
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.
Arranged in a broken shell some 3[degrees] across, these arcs are collectively known as the Cygnus Loop or Veil Nebula.
Another Milky Way mystery revolves around a 15,000-year-old supernova remnant called the Cygnus Loop. Astronomers have wondered whether the Loop might be part of a larger, gaseous region called the Cygnus Superbubble, which appears in the same general area of the sky.
SKYWATCHERS IN EARLY EGYPT AND MESOPOTAMIA MAY have witnessed two bright supernovae at the site of the Cygnus Loop, one of the best-studied supernova remnants in the sky.
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.
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.