Galaxy NGC 7217
History
On 7 September 1784 William Herschel discovered a «faint nebula» which he logged as II 207 and recorded: «Considerably large, round, gradually much brighter in the middle, easily resolvable.» [463] John Herschel made the single observation, measured an accurate position, logged it as h 2149 and recorded: «bright; round; 30"; gradually brighter in the middle.» [466] The Birr Castle team observed the nebula 14 times with the giant 72-inch telescope and logged on 16 September 1854: «There can hardly be a doubt that this nebula is a cluster.» [486]
Physical Properties
It is a galaxy of morphological type (R)SA(r)ab with a LINER-type active core. Distance specifications range from 16 Mpc to 18.4 Mpc. [145]
| Designation | NGC 7217 |
| Type | Gx (Sb) |
| Right Ascension (J2000.0) | 22h 07m 52.1s |
| Declination (J2000.0) | +31° 21' 34" |
| Diameter | 4 × 3.4 arcmin |
| Photographic (blue) magnitude | 11.0 mag |
| Visual magnitude | 10.1 mag |
| Surface brightness | 12.7 mag·arcmin-2 |
| Position Angle | 83° |
| Redshift (z) | 0.003176 |
| Distance derived from z | 13.42 Mpc |
| Metric Distance | 17.200 Mpc |
| Dreyer Description | B, pL, gbM, er |
| Identification, Remarks | WH II 207; h 2149; GC 4760; UGC 11914; MCG 5-52-1; CGCG 494-2; KARA 947; IRAS 22056+3106 |
Finder Chart
The galaxy NGC 7217 is located in the constellation Pegasus. The best observation time is June to December, when it is highest at night.
