Planetary Nebula IC 5117
The planetary nebula IC 5117 was discovered in 1905 by the Scottish-American astronomer Williamina Fleming. Dreyer described the nebula in his 1910 second index catalog as «planetary, stellar». [196, 315]
In fact, with an angular extent of only 1.2 arcseconds, the PN can hardly be distinguished from a star. The apparent brightness measured in different filters: V 16.7 mag, J 11.3 mag, H 10.7 mag, K 9.5 mag.
IC 5117 is a very young and compact planetary nebula. The gas surrounding the central star is still very dense with 90'000 molecules per cubic centimeter and very hot with a temperature of 12'000 Kelvin. The central star is estimated to have a temperature of 120'000 Kelvin. The distance is estimated to be 3 kpc (about 9700 light years). Exact measurements are not available. 
|Designations||PN G089.8-05.1: IC 5117, PK 89-05.1, ARO 112, VV 266, VV' 552|
|Right Ascension (J2000.0)||21h 32m 31s|
|Declination (J2000.0)||+44° 35' 48"|
|Dimensions||1.2" (optical), 1.5" (radio)|
|Radial Velocity||-26.1 km/s ± 1.3 km/s|
|Expansion Velocity||16.5 km/s (O-III), 21.5 km/s (N-II)|
|C-Star Designations||AG82 431, CSI +44-21305 0, EM* CDS 1256, HD 205211|
|C-Star Magnitude||17.5 mag (B filter), 16.7 mag (V filter)|
|C-Star Spectral Type||WR|
The planetary nebula IC 5117 is located in the constellation Cygnus (Swan). The best observation time is September to February
Description pending ...