Cirrus nebula

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Emission nebula
Cirrus nebula ( supernova remnant )

Recorded using a line filter for ionized gases: Hα, SII, OIII The light-colored filament on the left above the middle is designated NGC 6992 and 6995, the adjacent structure below with IC 1340; the right light filament with NGC 6960 and the star next to it with 52 Cygni. The two filaments in between bear the designation NGC 6974 (above, in the middle) and to the right of it, slightly lighter and larger, NGC 6979.

Recorded using a line filter for ionized gases: Hα, SII, OIII
The light-colored filament on the left above the middle is designated NGC 6992 and 6995, the adjacent structure below with IC 1340; the right light filament with NGC 6960 and the star next to it with 52 Cygni . The two filaments in between bear the designation NGC 6974 (above, in the middle) and to the right of it, slightly lighter and larger, NGC 6979.
AladinLite
Constellation swan
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 20 h 45 m 38.0 s
declination + 30 ° 42 ′ 30 ″
Appearance

Apparent brightness  (visual) 7.0 likes  
Angular expansion 3 ° 
Ionizing source
Physical data

distance  735 pc
diameter 150 × 120 ly
history

discovery Wilhelm Herschel
Date of discovery September 5, 1784
Catalog names
 NGC  6960, 6974, 6979, 6992, 6995 •  IC  1340 •  GC  4600, 5975, 4607, 4616, 4618 •  H  V 15, II 206, V 14 •  h  2088, 2092, 2093 •  Caldwell 33/34 • Ced 182

The Cirrus fog (also known as fog mist , English Veil nebula hereinafter) is the visible part of the spectrum in the optical Cygnusbogens , a collection of emission and reflection nebulae , which is at a distance of about 2,400 light-years in the constellation Cygnus located. Together they are the remnant of a supernova that took place around 8,000 years ago. Various parts of the remnant have different NGC and IC numbers. The objects NGC 6960 , NGC 6974 , NGC 6979 , NGC 6992 , NGC 6995 and IC 1340 all belong to the same structure.

Name of the object Right ascension declination m V Angular expansion Explorer Discovery date
NGC 6960 204558.220 h 45 m 58.2 s 2304543+ 30 ° 45 ′ 43 ″ 70.00 × 6.0 William Herschel September 7, 1784
NGC 6974 205104.320 h 51 m 04.3 s 2314941+ 31 ° 49 ′ 41 ″ Lawrence Parsons August 20, 1873
NGC 6979 20502820 h 50 m 28.0 s 2320133+ 32 ° 01 ′ 33 ″ 7.00 × 3.0 William Herschel September 7, 1784
NGC 6992 205619.120 h 56 m 19.1 s 2314434+ 31 ° 44 ′ 34 ″ 60.00 × 8.0 William Herschel September 5, 1784
NGC 6995 205710.720 h 57 m 10.7 s 2311407+ 31 ° 14 ′ 07 ″ 12.00 × 12.0 John Herschel September 7, 1825
IC 1340 205608.220 h 56 m 08.2 s 2310252+ 31 ° 02 ′ 52 ″ 25.00 × 20.0 Truman Henry Safford September 13, 1866

The nebula was discovered by William Herschel on September 5, 1784 . He described it as: “Extended; passes thro '52 Cygni ... near 2 degree in length “; the eastern part as "Branching nebulosity ... The following part divides into several streams uniting again towards the south."

Investigations

The first photographs were taken and published by Isaac Roberts at the end of the 19th century . Despite its total brightness of about 7 mag, the nebula is not easy to observe for amateur astronomers because of its large area of ​​230 ′ × 160 ′ ; Contrast- increasing fog filters are helpful . In photographs, especially in the short-wave spectral range, the fog stands out clearly.

Numerous studies on the structure and gas dynamics of supernova remnants have been and are being carried out on him , for example detailed studies with the Hubble space telescope . Photographs in different wavelength ranges, especially in the X-ray range by the ROSAT satellite , result in an overall picture of the nebula that is reminiscent of a light bulb in its outlines. The compact remnant ( neutron star , pulsar or black hole ) of the supernova is not known.

  • Hubble false color recording using several narrow-band filters (OIII blue; Hα green; SII red)

  • Filament on which velocity and ionized gases (OV, NV, CIV, HeII) were examined.

  • NGC 6992/6995, narrow band image (HA / OIII) with a 16-inch Newtonian telescope

Web links

Commons : Veil Nebula  - collection of images, videos and audio files

Individual evidence

  1. ↑ SIMBAD Astronomical Database. In: Results for Veil Nebula. Retrieved January 2, 2007 .
  2. ↑ SEDS: NGC 6960
  3. ↑ a b Robert A. fez, Kathryn E. Weil, Ignacio A. Cisneros, William P. Blair, John C. Raymond: The Cygnus Loop's distance, properties, and environment driven morphology . In: Monthly Notices of the Royal Astronomical Society . tape 481 , no. 2 , 2018, p. 1786-1798 , doi : 10.1093 / mnras / sty2370 .
  4. ^ [email protected]: Revisiting the Veil Nebula. Retrieved June 6, 2017 (UK English).
  5. ↑ a b Searching NED. In: NASA / IPAC EXTRAGALACTIC DATABASE. Retrieved May 1, 2019 .
  6. ↑ Seligman: NGC 6960
  7. ↑ Seligman: NGC 6974
  8. ↑ Seligman: NGC 6979
  9. ↑ Seligman: NGC 6992
  10. ↑ Seligman: NGC 6995
  11. ↑ Seligman: IC 1340
  12. ↑ A High-resolution X-ray Image of the Cygnus Loop. NASA's High Energy Astrophysic Science Archive Research Center.
  13. ^ Veil Nebula (X-rays).
  14. ↑ B. Uyanıker, W. Reich, A. Yar, R. Kothes, E. Fürst: Is the Cygnus Loop two supernova remnants? bibcode : 2002A & A ... 389L..61U .
  15. ^ William P. Blair, Ravi Sankrit, John C. Raymond: Hubble Space Telescope Imaging of the Primary Shock Front in the Cygnus Loop Supernova Remnant. (PDF; 1.1 MB), The Astronomical Journal, 129: 2268-2280, 2005.
  16. ↑ Ravi Sanskrit, William P. Blair, John C. Raymond, Knox S. Long: Hubble Space Telescope STIS Observations of the Cygnus Loop: Spatial Structure of a Nonradiative Shock. (PDF; 306 kB), The Astronomical Journal, 120: 1925–1932, 2000.