Saturn Nebula (NGC 7009)

NGC 7009
NGC 7009: Image taken with the ESO VLT telescope in Chile. © ESO [229]


This planetary nebula was discovered on 7 September 1782 by William Herschel with his small 6.2 inch reflecting telescope. He entered it as IV 1, where class «IV» applied to his visual classification for planetary nebulae, to which he also included unusual shapes such as «stars with burs, with milky chevelure, with short rays, remarkable shapes, etc.» He described the PN as a «very bright, nearly round planetary, not well defined disk». [463] NGC 7009 was later nicknamed the «Saturn Nebula» by Lord Rosse because of its elongated shape, reminiscent of Saturn's rings. [196] The PN was given the designation NGC 7009 by John L. E. Dreyer in his «New General Catalogue of Nebulae and Clusters of Stars» published in 1888. [313]

Physical Properties

NGC 7009
NGC 7009: HST image and schematic representation of the structure [234]

At Simbad one finds a distance of 1325 pc for NGC 7009. [145] Originally, the star had less than eight solar masses and shed its envelopes into space. The central star is now a hot white dwarf with an apparent magnitude of about 11.5, which causes the nebula's gas to glow green with its strong UV radiation. [234]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
Designations PN G037.7-34.5: NGC 7009, PK 37-34.1, ARO 16, VV 259, VV' 541, EM* CDS 1211
Right Ascension (J2000.0) 21h 04m 11s
Declination (J2000.0) -11° 21' 57"
Dimensions 28.5" (optical)
Distance 0.60 kpc
Radial Velocity -44.0 ± 3.0 km/s
Expansion Velocity 20.6 (O-III) 20.0 (N-II) km/s
C-Star Designations AG82 419, BD -11 5511, GCRV 13233, HD 200516, TD1 27614
C-Star Magnitude B: 12.66, V: 12.78
C-Star Spectral Type O(H)
Discoverer HERSCHEL 1782

Finder Chart

The Saturn Nebula is located in the constellation Aquarius, north of Capricornus (Capricornus). The best observation time is July to December.

Finder Chart Saturn Nebula (NGC 7009)
Saturn Nebula (NGC 7009) in constellation Aquarius. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Visual Observation

635 mm Aperture: The Saturn Nebula NGC 7009 immediately appears as a bright oval with a dark inner part, in which the central star can be temporarily observed. To the right of the elongation, there is a slightly brighter point, which is connected to the oval in a streak-like manner. This is mirrored on the left side, albeit slightly fainter. When magnified further, a faint halo around the oval becomes visible, creating an overall round impression. — 25" f/4 Obsession-Dobson, Tivoli-Astrofarm at 1340m AMSL in Namibia, SQM 21.92 m/s2, 11. 9. 2023, Stefan Meister, Eduard von Bergen

Objects Within a Radius of 15°