The Cygnus Loop is a large old supernova remnant in Cygnus whose brightest filaments form the Veil Nebula, the shock of an explosion meeting the gas around it.
At a glance
| type | supernova remnant |
|---|---|
| distance from the Sun | 2,400 light-years (735 pc) |
| its light left it | 2,400 years ago |
| size in the piece | about 120 light-years acrossmodel |
Read off the piece’s own catalogue, the same values it draws with. Model marks a property of the piece’s galaxy model rather than a measurement.
About Cygnus Loop
The explosion that made the Cygnus Loop happened long ago, and its blast wave has since slowed and spread across a region of sky much wider than the full Moon. Its bright edges, known as the Veil Nebula, glow where the shock runs into denser clouds; William Herschel found the brightest parts with a telescope.
The shocked gas inside is hot enough to shine in X-rays, while the filaments at the edge glow in visible light from hydrogen, oxygen and sulphur as the gas cools behind the shock. Hubble images show the filaments as thin, rippled sheets seen edge-on.
Because it is close and middle-aged, it is a reference case for how a remnant behaves once its blast has slowed and begun to radiate its energy away.
What you see in the piece
It is drawn as a hollow shell of shocked gas with a rippled skin, faint in visible light from the Sun; the radio band shows its shell, and up close it surrounds you.
Measured or modelled
Its distance has been revised more than once; the age and the drawn extent are inferred and modelled.
Questions
What is the Veil Nebula?
It is the brightest part of the Cygnus Loop, the filaments where the shock wave of an ancient supernova is hitting the surrounding interstellar gas.
How far away is the Cygnus Loop?
The Cygnus Loop is about 2,400 light-years (735 pc) from the Sun.