Claw Galaxy (NGC 247)

NGC 247
NGC 247: Claw Galxy in Cetus; TEC APO 140 ED refractor, f=980 mm; SBIG STT-8300 SG/AO-8T; Losmandy G11 + FS2; L 28×10 min; R 16×5 min; G 12×5 min; B 11×5 min; -40 °C; Astrofarm Tivoli, Namibia; © 23. – 27. August 2014 Hansjörg Wälchli [46]


This galaxy was discovered by William Herschel on 20 October 1784 using his 18.7 inch reflector. He cataloged it as V 20 (class V = very large nebulae) and noted: «A streak of light, nearly along the meridian, 26' long, 3 or 4' broad, pretty bright.» [463] Dreyer added it as NGC 247 to his «New General Catalogue» published in 1888. [313]

Physical Properties

NGC 247 is a dwarf, low surface brightness galaxy and of morphological type SAB(s)d. It is part of the Sculptor Group, a collection of galaxies associated with the Sculptor Galaxy (NGC 253). This is the nearest group of galaxies to the Local Group, which includes our Milky Way. A remarkable feature of this galaxy is a large void in the northern part of the disk. At a distance of about 3.5 Mpc, the void region in NGC 247 is approximately 3.4 kpc long. This is not empty space, but it contains mostly older, redder stars and no blue, younger stars. An analysis of age versus radius suggests little to no star formation in the void for more than 1 Gyr. It is speculated that it is caused by a recent interaction with a nearly dark subhalo that collided with the disc. [632]

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
Designation NGC 247
Type Gx (SBcd)
Right Ascension (J2000.0) 00h 47m 08.3s
Declination (J2000.0) -20° 45' 36"
Diameter 19.2 × 5.5 arcmin
Photographic (blue) magnitude 9.7 mag
Visual magnitude 9.1 mag
Surface brightness 14.4 mag·arcmin-2
Position Angle 172°
Redshift (z) 0.000520
Distance derived from z 2.20 Mpc
Metric Distance 3.590 Mpc
Dreyer Description F, eL, vm E 172°
Identification, Remarks WH V 20; h 57; GC 132; ESO 540-22; MCG -4-3-5; UGCA 11; IRAS 00446-2101

Finder Chart

The galaxy NGC 247 is located in the constellation Cetus. Just 4.5° to the south is the Silverdollar (NGC 253). The best observation time is September to December.

Finder Chart Claw Galaxy (NGC 247)
Claw Galaxy (NGC 247) in constellation Cetus. 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 20°


  • [46] Astrofotografie mit Hansjörg Wälchli;
  • [149] SkySafari 6 Pro, Simulation Curriculum;
  • [160] The STScI Digitized Sky Survey;
  • [277] «Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; (2021-02-17)
  • [313] «A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged» Dreyer, J. L. E. (1888); Memoirs of the Royal Astronomical Society. 49: 1–237; Bibcode:1888MmRAS..49....1D
  • [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
  • [632] «The void in the Sculptor group spiral galaxy NGC 247» R. Wagner-Kaiser, T. De Maio, A. Sarajedini, S. Chakrabarti; Monthly Notices of the Royal Astronomical Society, Volume 443, Issue 4, 1 October 2014, Pages 3260–3269; DOI:10.1093/mnras/stu1327