Pair Galaxies NGC 470/4 (Arp 227)

NGC 470, 474
NGC 470, 474: Galaxies in Pisces; 500 mm Cassegrain f/7.2; SBIG STL11K; 310-70-70-70 min LRGB; Bernese Highlands; © 2015 Radek Chromik

History

The galaxies NGC 470 and NGC 474 were discovered on 13 December 1784 by the German-British astronomer William Herschel with his self-made 18.7 inch f/12.8 reflecting telescope in Slough, England. On October 8 of the following year, he came across NGC 467. [277] In Halton Arp's 1966 «Atlas of Peculiar Galaxies», the galaxy NGC 474 is listed with Arp 227 as an example of a galaxy with concentric rings. [199]

Physical Properties

The elliptical galaxy NGC 474 has a spectacular system of surrounding shells and tidal currents, which could be traced back to an earlier interaction or merging with another galaxy about two billion years ago. From the galaxy NGC 470, which is only 47 kpc away, cold gas is withdrawn in the outer areas. [446] Distances from NGC 470 and NGC 474 to Earth range from 27 Mpc to 41 Mpc. The galaxy NGC 457 is much further away at 73 Mpc to 78 Mpc. [145]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 46701 19 10.1+03 18 05Gx (S0)12.911.81.7 × 1.7pB, pL, R, gbMUGC 848, MCG 0-4-79, CGCG 385-65
NGC 47001 19 44.8+03 24 33Gx (Sb)12.511.82.9 × 1.7pB, L, iRUGC 858, MCG 0-4-84, CGCG 385-70, Arp 227, IRAS 01171+0308
NGC 47401 20 06.7+03 24 58Gx (S0)12.411.57.1 × 6.3pB, S, smbM, f of 2UGC 864, MCG 0-4-85, CGCG 385-71, Arp 227

Finder Chart

The galaxy is located in the constellation Pisces. The best time to observe is December to June, when it is highest at night.

Chart Pair Galaxies NGC 470/4 (Arp 227)
Pair Galaxies NGC 470/4 (Arp 227) in constellation Pisces. 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
199«Atlas Of Peculiar Galaxies», Halton Arp, 1966; Astrophysical Journal Supplement, vol. 14, p.1 (1966); DOI:10.1086/190147; Bibcode:1966ApJS...14....1A
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
446«NGC 474 as viewed with KCWI: diagnosing a shell galaxy» Adebusola B Alabi, Anna Ferré-Mateu, Duncan A Forbes, Aaron J Romanowsky, Jean P Brodie; Monthly Notices of the Royal Astronomical Society, Volume 497, Issue 1, September 2020, Pages 626–631; DOI:10.1093/mnras/staa1992