NGC 7026, Cheeseburger Nebula
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 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]
| Designations | PN 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 Designations | AG82 420, CSI +47 -21046, HD 201192, PLX 5080 |
| C-Star Magnitude | 15.33 mag (B filter), 14.20 mag (V filter) |
| C-Star Spectral Type | O VI, WC 3 |
| Discoverer | COPELAND 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.
