Helix Nebula

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Planetary Nebula
Data of the Helix Nebula
NGC7293 (2004) .jpg
Superimposed image of the Hubble Space Telescope and the 4 m telescope of the Cerro Tololo Inter-American Observatory
AladinLite
Constellation Aquarius
Position
equinox : J2000.0
Right ascension 22h 29m 38.55s
declination -20 ° 50 ′ 13.6 ″
Appearance
Apparent brightness  (visual) +7.3 mag 
Apparent brightness  (B-band) +7.5 mag 
Angular expansion 16 ′ × 28 ′  
Central star
Physical data
Redshift (-50 ± 33)  ·  10 −6 
Radial velocity (-15 ± 10) km / s 
distance 650 ly 
history
discovery Karl Ludwig Harding
Date of discovery September 1823
Catalog names
 NGC  7293 •  PK  36-57.1 •  ESO  602-PN22 •  GC  4795 •  BD  -21 6239

The Helix Nebula (also NGC 7293 or Eye of God ) is a planetary nebula in the constellation Aquarius with a brightness of 6.30  mag and an apparent diameter of 16 '× 28'. It was discovered in 1823 by the German astronomer Karl Ludwig Harding .

The Helix Nebula is the closest planetary nebula at a distance of about 650  light years and thus the one with the largest apparent diameter. Therefore, details of the gas structure can also be resolved in its envelope.

With the Hubble telescope in 1996 it was even possible for the first time to record nodes in the shell that were previously unknown and allowed new conclusions to be drawn about the formation of planetary nebulae. But they also raised new questions. It is not clear whether the nodal germs arose during the ejection of the shell or whether they originate from activity of the star before the ejection. It is also controversial whether the nodes are hydrodynamic structures (i.e. created by instabilities) or whether they are formed by photoionization of the gas by the white dwarf in the center.

The nebula is also known as the Eye of God , especially since rumors began to spread on the internet after a Hubble recording of the nebula was released in 2003 that the nebula recording showed an event that only occurs every 3,000 years.

  • UV absorption: 135 ... 270 nm ( GALEX )

  • IR image: blue 3.6 ... 4.5 µm, green 5.8 ... 8 µm, red 24 µm ( Spitzer Space Telescope )

  • Node inside the Helix Nebula (detailed view of Hubble)

  • Structures of the Helix Nebula.

Web links

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

Individual evidence

  1. ↑ a b SIMBAD database
  2. ^ A b Students for the Exploration and Development of Space
  3. ↑ https://cseligman.com/text/atlas/ngc72a.htm#7293
  4. ↑ Florian Rötzer: The Helix Nebula or God's Eye , in: Telepolis, May 26, 2009 (accessed May 17, 2014).