NGC 70 Galaxy Group

NGC 70
NGC 70: Galaxy group in Andromeda; North is left; 500 mm Cassegrain f/7.2; SBIG STL11K; 120-40-40-4 0 min LRGB; Bernese Highlands; © 2011 Radek Chromik

History

The galaxies NGC 68, NGC 70, NGC 71 and NGC 72 were discovered on 11 September 1784 by the German-British astronomer William Herschel with his 18.7 inch reflector telescope. On 7 October 1855, RJ Mitchell, assistant to William Parsons, 3rd Earl von Rosse, directed the huge 72 inch reflector telescope at this group of galaxies and discovered other galaxies: NGC 67, NGC 69 and NGC 74. The somewhat remote galaxy NGC 76 had to wait until 22 September 1884 to be discovered by the French astronomer Guillaume Bigourdan with a 12.4 inch refractor telescope. His observation also led to IC 1539, a duplicate entry from NGC 70. [277]

Boris Aleksandrovich Vorontsov-Velyaminov lists this group of galaxies in his «Atlas and Catalog of Interacting Galaxies» published in 1959 as VV 166. [432] In Halton Arps' 1966 published «Atlas of Peculiar Galaxies» it is listed under Arp 113 as closely related and interfering spiral galaxies Find. [199]

Physical Properties

NGC 70 belongs to a compact group of seven or eight galaxies and shows similarities to Stephan's Quintet (HCG 92) in the neighboring constellation Pegasus. NGC 68 shows a smaller redshift than the other galaxies in the group and also shows no gravitational changes. It is probably not one of them and is in the foreground. [433, 434] However, a more modern analysis of SDSS DR12 lists NGC 68 as member of the MLCG 1437 galaxy group. [562] The distance of the group to the Milky Way is around 90 Mpc to 96 Mpc. [145]

This group of galaxies is often called the «VV 166 Group». Some also refer to it as the «NGC 70 Group» because NGC 70 is the largest member, others refer to it as the «NGC 68 Group» because NGC 68 is the brightest member. As true gravitational membership of NGC 68 to that group is not certain, the designation «NGC 70 Group» seems hence to be more accurate.

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 6700 18 14.9+30 03 48Gx (E3)15.214.20.3 × 0.2eF, vS, RMCG 5-1-64, CGCG 499-104, ARAK 4, Arp 113, VV 166
NGC 67 A00 18 12.1+30 03 19Gx (E5)15.714.70.4 × 0.2eF, vS, RArp 113, VV 166
NGC 6800 18 18.2+30 04 21Gx (E-S0)13.912.91.2 × 1.1eF, L, 3 or 4 st + nebUGC 170, MCG 5-1-65, CGCG 499-106, Arp 113, VV 166, IRAS 00157+2947
NGC 6900 18 20.4+30 02 26Gx (E/SB0)15.814.70.5 × 0.3eF, vS, RMCG 5-1-66, CGCG 499-105, ARAK 5, Arp 113, VV 166, NPM1G +29.0011
NGC 7000 18 22.4+30 04 44Gx (Sbc)14.313.51.6 × 1.4eF, vS, R, bet 2 F stIC 1539, UGC 174, MCG 5-1-67, CGCG 499-108, Arp 113, VV 166
NGC 7100 18 23.5+30 03 47Gx (E-S0/P)14.213.21.2 × 0.9eF, vS, RUGC 173, MCG 5-1-68, CGCG 499-107, Arp 113, VV 166
NGC 7200 18 28.4+30 02 26Gx (SBab)14.513.51.1 × 0.9eF, vS, RUGC 176, MCG 5-1-69, CGCG 499-109, Arp 113, VV 166
NGC 72 A00 18 34.3+30 02 10Gx (E3)15.714.70.3 × 0.3eF, vS, RMCG 5-1-70, CGCG 499-110, ARAK 6, VV 166
NGC 7400 18 49.5+30 03 41Gx (Sb)15.614.80.8 × 0.3eF, S, E, last of 6MCG 5-1-71
NGC 7600 19 37.7+29 56 03Gx (C)14.113.11 × 0.9vF, S, bMUGC 185, MCG 5-1-72, CGCG 499-111

Finder Chart

The NGC 70 galaxy group is located in the constellation Andromeda. The best observation time is July to September, when it is highest at night.

Chart NGC 70 Galaxy Group
NGC 70 Galaxy Group in constellation Andromeda. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

Visual Observation

320 mm Aperture: Of the galaxy group around NGC 70, which counts 8 to 10 galaxies, only the four bright ones were easy to identify with the 12.5" Dobsonian. They were NGC 68, NGC 70, NGC 71 and NGC 72. The other much fainter galaxies are then challenges for a larger Dobsonian. — 12.5" f/4.5 Ninja-Dobsonian, Glaubenberg, 2. 8. 2022, Eduard von Bergen

More Objects Nearby (±15°)

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)
432«The Atlas and Catalogue of Interacting Galaxies» B.A. Vorontsov-Velyaminov (Moscow 1959); ned.ipac.caltech.edu/level5/VV_Cat/frames.html (2021-09-25)
433«Tidal effects as criteria for membership in small groups of galaxies: application to VV 166.» Kormendy, J.; Sargent, W. L. W.; Astrophysical Journal, Vol. 193, p. 19-25 (1974); DOI:10.1086/153122
434«Galaxy collisions in dense groups.» Hickson, P.; Richstone, D. O.; Turner, E. L.; Astrophysical Journal, Vol. 213, p. 323-326 (1977); DOI:10.1086/155158
562«Catalogs of Compact Groups of Galaxies from the Enhanced SDSS DR12» Jubee Sohn, Margaret J. Geller, Ho Seong Hwang, H. Jabran Zahid, and Myung Gyoon Lee; The Astrophysical Journal Supplement Series, Volume 225, Number 2, 2016; DOI:10.3847/0067-0049/225/2/23