The Cygnus Loop (radio source W78, or Sharpless 103) is a large supernova remnant (SNR) in the constellation Cygnus, an emission nebula measuring nearly 3° across. Some arcs of the loop, known collectively as the Veil Nebula or Cirrus Nebula, emit in the visible electromagnetic range. Radio, infrared, and X-ray images reveal the complete loop. Visual components: the Veil Nebula The visual portion of the Cygnus Loop is known as the Veil Nebula, also called the Cirrus Nebula or the Filamentary Nebula. Several components have separate names and identifiers, including the "Western Veil" or "Witch's Broom", the "Eastern Veil", and Pickering's Triangle. NGC 6960 NGC 6960, the Western Veil, is the western part of the remnant, also known as the "Witch's Broom", located at J2000 RA Dec . As the westernmost NGC object in the nebula (first in right ascension), its number is sometimes used as an NGC identifier for the nebula as a whole. NGC 6992, NGC 6995, and IC 1340 These three luminous areas make up the Eastern Veil. NGC 6992 is an HI shell located along the north-eastern edge of the loop at J2000 RA Dec . NGC 6995 is located farther south at J2000 RA Dec , and IC 1340 even farther south at J2000 RA Dec . Pickering's Triangle Also known as Pickering's Wedge, or Pickering's Triangular Wisp, this segment of relatively faint nebulosity was discovered photographically in 1904 by Williamina Fleming at Harvard Observatory, where Edward Charles Pickering was director at the time. The Triangle is brightest along the northern side of the loop, though photographs show the nebulosity extending into the central area as well. NGC 6974 and NGC 6979 These two objects are generally identified today (as by the NGC/IC Project and Uranometria) with two brighter knots of nebulosity in a cloud at the northern edge of the loop, to the east of the northern edge of Pickering's Triangle. NGC 6979 was reported by William Herschel, and while the coordinates he recorded for Veil objects were somewhat imprecise, his position for this one is tolerably close to the knot at J2000 RA Dec . The identifier NGC 6979 is sometimes taken to refer to Pickering's Triangle, but the Triangle is probably not what Herschel saw or what the Catalogue intended for this entry: it was discovered only photographically, after the Catalogue was published, and long after Herschel's observation. NGC 6974 was reported