Veil Nebula: Definition, Observation, Composition

The Veil Nebula, known as the Cygnus Loop, is a gigantic supernova remnant in the constellation Cygnus. It is a huge and intricate area of nebulosity, one of the largest and brightest among known remnants. The delicate network of glowing gaseous filaments derives its name from its draped filamentary structures, and it constitutes the visible portions of the expanding bubble of debris that lies along the edge of a large, low-density gaseous bubble.

What is the Veil Nebula?

The Veil Nebula is a cloud of heated and ionized gas and dust, which constitutes the visible portions of the Cygnus Loop. This nebula is in Cygnus and refers to the visible structure of the remnant, which is an expanding bubble of debris from a supernova explosion. The Veil Nebula refers to the entire loop, a supernova remnant, and its core possibly is a neutron star or a black hole.

The Veil Nebula derives its name from its delicately draped filamentary structures. Because these gossamer arcs resemble a translucent curtain, it is known as the Bridal Veil Nebula and the Network Nebula. The same lacework appearance has earned it the nicknames Cirrus Nebula, Filamentary Nebula, Lacework Nebula, Witch’s Broom Nebula, Finger of God, and simply the Veil Nebula Complex.

Beyond the shared name, each bright segment carries its own designation. The Western Veil Nebula is catalogued NGC 6960 and is called Caldwell 34. The Eastern Veil Nebula is NGC 6992, known as Caldwell 33 and Network Nebula, and is one of the brightest areas of the Cygnus Loop. Pickering’s Triangle, another prominent section, is designated NGC 6974 and is sometimes termed Pickering’s Triangular Wisp. Additional catalog numbers found within the loop are NGC 6979, NGC 6974, NGC 6995, and IC 1340. Collectively these names and numbers refer to the same 110-light-year-wide expanding bubble of debris from a star that exploded about 8,000 years ago, forming one of the largest, brightest, and most important X-ray sources among known supernova remnants.

What are the parts of the Veil Nebula?

The Veil Nebula has three main parts – Eastern Veil, Western Veil, Pickering’s Triangle. The parts of the Veil Nebula are detailed below.

• Eastern Veil Nebula (NGC 6992, NGC 6995, IC 1340): Titled the Network Nebula, the brightest region of the Eastern Veil Nebula is designated NGC 6992. NGC 6992 lies along the northeastern border of the Cygnus Loop. 
• Western Veil Nebula (NGC 6960): Titled the Witch’s Broom, the Western Veil Nebula lies near the foreground star 52 Cygni. It is the western-most part in the Veil Nebula and spans a region of about 35 light years. Other monikers include Filamentary Nebula, Finger of God Nebula, Lacework Nebula, and Caldwell 34. 
• Pickering’s Triangle (Fleming’s Triangle): Known as Pickering’s Triangular Wisp and Simeis 3-188, it lies at the north central edge of the Cygnus Loop and contains the bright patch Simeis 3-210. It is brightest along the northern side. It was originally named after Edward Charles Pickering, the director of Harvard Observatory.

How to find Veil Nebula?

To find the Veil Nebula, begin at the brightest star of Cygnus, Deneb, and sweep 3 degrees south-west to meet the Western Veil Nebula that glows beside the naked-eye star 52 Cygni. This star guides the eye to NGC 6960, a filament whose magnitude 7 makes it detectable with small binoculars. From 52 Cygni, slide the telescope eastward along the swan’s outstretched wings to catch the Eastern Veil, while the entire Cygnus Loop, equal to six full-moons wide, arcs across a 3-degree span of night sky. A Dobsonian telescope with at least 20.32 centimeters (8 inches) of aperture, fitted with an OIII filter, gathers enough of the shocked oxygen light to reveal the lacework of this supernova remnant, even from suburban skies 448.416 meters (1,470 feet) away.

Is the Veil Nebula a supernova remnant?

The Veil Nebula is a supernova remnant. Veil Nebula is one of best-known supernova remnants. A massive star exploded about 8,000 years ago and the light from this supernova explosion reached Earth about 5000 years ago. The Veil Nebula is prototypical middle-aged supernova remnant. The Veil Nebula is ideal for studying physics of supernova remnants.

Is the Veil Nebula a star-forming nebula?

The Veil Nebula is a supernova remnant, not a star-forming nebula. Its shock front heats and ionizes surrounding gas, yet this heating destroys dense clumps rather than compressing them into new stars. The Ultraviolet Imaging Telescope observed a handful of stars behind the Veil Nebula, including star KPD2055+311, which is at a distance that places it behind the Veil Nebula. These objects merely lie along the same sightline and were born elsewhere. Veil Nebula’s progenitor star was once 20 times as massive as the Sun, and its cataclysmic death roughly 10,000 years ago produced the fast‑moving shock wave that plows into edges or walls of cavity, explaining the filamentary glow captured by Hubble images using oxygen (blue).

What is the Veil Nebula made of?

The Veil Nebula is a cloud of heated and ionized gas and dust created by the death of an exploded star. Analysis of the emissions from the nebula indicates the presence of oxygen, sulfur, and hydrogen.

In the Western Veil Nebula, oxygen glows blue, sulfur glows green, and red corresponds to the glow of hydrogen. The same gases color the Eastern Veil Nebula, so the Cygnus Loop shares this uniform composition across its entire supernova remnant.

What is the difference between the Veil Nebula and the Crab Nebula?

Differences between the Veil Nebula and the Crab Nebula are explained in the table below.