Eastern Veil Nebula
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The Cygnus Loop is a vast yet relatively faint supernova remnant in the constellation Cygnus, located roughly 1,440 light-years from Earth. Its brightest filaments were first observed in September 1784 by William Herschel. Forty-one years later his son, John Herschel, revisited the same region and identified additional fragments of this peculiar nebula. Throughout the nineteenth century other observers — Truman Safford and Lawrence Parsons — and, in the early twentieth century, Williamina Fleming, kept adding pieces to the cosmic puzzle, still unaware that they were all looking at parts of a single, sprawling structure. One such segment is the Eastern Veil Nebula, cataloged as NGC 6992.
Observations
June 12, 2025, around 10:30 p.m. – Katowice
Conditions: urban site with very high light pollution
June skies extend an open invitation to stargazers. Ideally, you’d aim both your eyes and your camera at a truly dark sky far from populated areas, yet even from the city you can glimpse showpieces such as the Eastern Veil NGC 6992 (Photo 1), along with neighboring nebulae in the Loop — NGC 6995 and IC 1340.
The shock wave produced by the supernova explosion roughly 10,000 years ago sculpted the delicate nebular structures — including the Eastern Veil — by plowing into the relatively stationary interstellar gas. Excitation of the gas yields the vivid colors we see in visible light.
Measurements indicate that the blast wave is currently expanding at about 170 km/s (106 mi/s). Over the next several millennia the nebular material will keep dispersing, returning heavier elements — such as gold, calcium, and iron — back to the interstellar medium.
Photo 1 parameters:
- Total exposure time: 105 minutes (stack of 420 RAW frames at 15s each)
- stacking: Siril
- DWARF3
- Lens: f=150mm (aperture: 35mm)
- Mount: photographic tripod
Further reading:
- Gendler R., Niebo, Carta Blanca, 2007
- Greidanus H., Strom R.G., Optical kinematics in the Cygnus Loop. II. Interpretation, Astronomy and Astrophysics, 257 (1), 1992, pp. 265–277
- Fesen R.A., Blair W.P., Kirshner R.P., Spectrophotometry of the Cygnus Loop, The Astrophysical Journal, 262, 1982, p. 171
Marek Ples