Galaxy NGC 7217

NGC 7217
NGC 7217: Galaxy in Pegasus; 500 mm Cassegrain f/7.2; SBIG STL11K; 190-50-50-50 min LRGB; Bernese Highlands; © 2015 Radek Chromik [32]

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]

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
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
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.

Finder Chart Galaxy NGC 7217
Galaxy NGC 7217 in constellation Pegasus. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°

References

  • [32] Astrofotografie by Radek, Bernie and Dragan; sternwarte.ch
  • [145] SIMBAD astronomical database; simbad.u-strasbg.fr/simbad
  • [149] SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
  • [160] The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
  • [277] «Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
  • [463] «Catalogue of one thousand new nebulae and clusters of stars» William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1786; DOI:10.1098/rstl.1786.0027
  • [466] «Observations of nebulæ and clusters of stars, made at Slough, with a twenty-feet reflector, between the years 1825 and 1833» John Frederick William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1833, Pages: 359-505; DOI:10.1098/rstl.1833.0021
  • [486] «On the construction of specula of six-feet aperture; and a selection from the observations of nebulæ made with them» William Parsons; Philosophical Transactions of the Royal Society of London, Volume 151, published 1 January 1861; DOI:10.1098/rstl.1861.0029