Knife Edge Galaxy, Splinter Galaxy (NGC 5907)

Object Description

NGC 5907
NGC 5907: Galaxie in Draco; 500 mm Cassegrain f/7.2; SBIG STL11K; 100-20-20-20 min LRGB; Bernese Highlands; © 2011 Radek Chromik

On 5 May 1788, the German-British astronomer William Herschel discovered the nebula NGC 5907 with his 18.7 inch reflecting telescope. He cataloged it as II 759 and described it as «pretty bright, faint nucleus in the middle, 8 or 10' long, 2' broad» [464] On 13 April 1850, the Irish astronomer George Johnstone Stoney, an assistant to William Parsons, third Earl of Rosse, pointed his huge 72 inch reflecting telescope at this nebula and saw to the west of it a parallel ray, identified by John L. E. Dreyer as NGC 5906 included in his 1888 «New General Catalog of Nebulae and Clusters of Stars». [277, 313]

At the time of their discovery, the true nature of such nebulae was entirely unknown. What Stoney saw then was the fainter western part of this edge-on galaxy, separated by the band of dust. Because of its appearance, the galaxy was nicknamed the «Knife Edge Galaxy» or sometimes the «Splinter Galaxy».

A remarkable detail of NGC 5907 only becomes visible in very long exposures: a tidal current that spirals in a wide spiral around the galaxy. This is a remnant of a past merger with a dwarf galaxy, which orbited the host galaxy several times, each time losing some of its mass before finally being fully incorporated. [441, 442] Distances range from 12.9 Mpc to 17.3 Mpc. [145]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 590615 15 52.1+56 19 50GxyP14.50.1A ray, vmE, par to h 1917 and close p itpart (knot) in N 5907
NGC 590715 15 53.8+56 19 49Gx (Sc)11.110.312.6 × 1.4cB, vL, vmE 155°, vg, psbMNUGC 9801, MCG 9-25-40, IRAS 15146+5629, CGCG 274-38, CGCG 297-10, FGC 1875

Finder Chart

The galaxies NGC 5907 is located in the constellation Draco. The best viewing time is March to September when it is highest at night.

Chart Knife Edge Galaxy, Splinter Galaxy (NGC 5907)
Knife Edge Galaxy, Splinter Galaxy (NGC 5907) in constellation Draco. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

More Objects Nearby (±20°)

References

145SIMBAD astronomical database; simbad.u-strasbg.fr/simbad
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The 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)
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
441«The Ghost of a Dwarf Galaxy: Fossils of the Hierarchical Formation of the Nearby Spiral Galaxy NGC 5907»; cosmotography.com/images/small_ring_ngc5907.html (2021-10-05)
442«The Ghost of a Dwarf Galaxy: Fossils of the Hierarchical Formation of the Nearby Spiral Galaxy NGC 5907» David Martínez-Delgado, Jorge Peñarrubia, R. Jay Gabany, Ignacio Trujillo, Steven R. Majewski, and M. Pohlen; The Astrophysical Journal, Volume 689, Number 1, 2008; DOI:10.1086/592555
464«Catalogue of a second thousand of new nebulae and clusters of stars; with a few introductory remarks on the construction of the heavens» William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1789; DOI:10.1098/rstl.1789.0021