NGC 7026, Cheeseburger Nebula

NGC 7026
NGC 7026: Planetary nebula in Cygnus; 500 mm Cassegrain 3625 mm f/7.2; SBIG STL11K; 145+3*90 min LRGB; Bernese Highlands; © 2011 Radek Chromik

History

The planetary nebula NGC 7026 was discovered on July 6, 1873 by the American astronomer Sherburne Burnham and independently on November 18, 1880 by the British astronomer Ralph Copeland. J. L. E. Dreyer described it in his 1888 NGC catalog as «a fairly bright planetary nebula with two cores.» [196, 313]

Physical Properties

NGC 7026
NGC 7026: Image taken with the Hubble Space Telescope [346]

NGC 7026 is a complex, bipolar nebula. It consists of three opposite polar pairs of lobes and four sets of nodes, all symmetrical about the core, and a conical outlet. The nebula shows a strongly ionized structure. Investigations with the XMM-Newton telescope showed X-rays emanating from the bipolar lobes, suggesting a temperature of the escaping gas of around 1.1 million Kelvin. At the center is a hydrogen-poor WC star, a subset of Wolf-Rayet stars. Along the main axis of symmetry, the nebula is expanding at 150 km/s and the equatorial ring is expanding at about 57 km/s. The age of the nebula is estimated at 1500 years. The main axis of the nebula is tilted about 75° in our direction. The distance to NGC 7026 is estimated at 2086 ± 420 pc, about 6800 ± 1300 light years. [344, 345]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
DesignationsPN G089.0+00.3: NGC 7026, PK 89+00.1, ARO 59, EM* CDS 1218, VV 260, VV' 542
Right Ascension (J2000.0)21h 06m 19s
Declination (J2000.0)47° 51' 08"
Dimensions 20." (optical)
Distance 2.5 kpc
Radial Velocity-40.6 km/s ± 0.6 km/s
Expansion Velocity 38. km/s (O-III), 52.5 km/s (N-II)
C-Star DesignationsAG82 420, CSI +47 -21046, HD 201192, PLX 5080
C-Star Magnitude15.33 mag (B filter), 14.20 mag (V filter)
C-Star Spectral TypeO VI, WC 3
DiscovererCOPELAND 1880

Finder Chart

The planetary nebula NGC 7026 is located in the constellation Cygnus. The best observing time is April to November, when the PN is highest in the night sky.

Chart NGC 7026
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

References

141Strasbourg-ESO Catalogue of Galactic Planetary Nebulae; A. Acker, F. Ochsenbein, B. Stenholm, R. Tylenda, J. Marcout, C. Schohn; European Southern Observatory; ISBN 3-923524-41-2 (1992); cdsarc.unistra.fr/viz-bin/cat/V/84 (2021-02-18)
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
313«A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged» Dreyer, J. L. E. (1888); Memoirs of the Royal Astronomical Society. 49: 1–237; Bibcode:1888MmRAS..49....1D
344«A DETAILED SPATIOKINEMATIC MODEL OF THE CONICAL OUTFLOW OF THE MULTIPOLAR PLANETARY NEBULA NGC 7026» D. M. Clark, J. A. López, W. Steffen, and M. G. Richer; Published 2013 January 22; The Astronomical Journal, Volume 145, Number 3; DOI:10.1088/0004-6256/145/3/57
345«XMM-Newton Observations of the Bipolar Planetary Nebulae NGC 2346 and NGC 7026» Robert A. Gruendl, Martín A. Guerrero, You-Hua Chu, and Rosa M. Williams; The Astrophysical Journal, Volume 653, Number 1, 2006; DOI:10.1086/507940
346Hubble Sees a Celestial Swan and Butterfly; nasa.gov/mission_pages/hubble/science/ngc7026.html (2021-05-14)