IC 5217
Planetary Nebula in the constellation of Lacerta
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IC 5217 is a planetary nebula in the northern constellation of Lacerta.[2] It was discovered in 1904 by Scottish astronomer Williamina Fleming.[4][5] In 1910, the planetary was included as entry No. 5217 in the Second Index Catalogue of Nebulae and Clusters of Stars by J. E. L. Dreyer.[6] It requires a telescope to view, having an apparent visual magnitude of 12.6 and an angular size of 7″.[2]
| Emission nebula | |
|---|---|
| Planetary nebula | |
Filtered Pan-STARRS image of IC 5217, showing the equatorial ring | |
| Observation data: J2000 epoch | |
| Right ascension | 22h 23m 55.718s[1] |
| Declination | 50° 58′ 00.464″[1] |
| Apparent magnitude (V) | 12.6[2] |
| Apparent dimensions (V) | 7″[2] |
| Constellation | Lacerta |
| Designations | PN 100.6 −5.4, HD 212534[3] |
Spectra indicate the composition of this nebula is relatively homogeneous with only a low level of interstellar absorption.[7] Images of this nebula show bipolar lobes oriented along an east-west axis. These extend up to 15″ from the midpoint. The orientation of the nebula is along a position angle of 92°. An elongated structure around the waist is likely a bright equatorial ring that is being viewed from edge-on, at right angles to the lobes. The ring shows a velocity gradient that increases up to 27 km s–1 on the leading edges. Radio data indicates the ring is a flat disk with a hole in the center.[8]
The central star displays Wolf–Rayet characteristics with a spectral type of WC 7.[9] It has an apparent visual magnitude of 15.5 with an effective temperature in the range 92,000–95,000 K. The nebula was probably formed by an oxygen-rich progenitor. It appears depleted in carbon and helium compared to similar nebulae.[10]