Pair of Galaxies NGC 3395/6 (Arp 270)

NGC 3395/6
NGC 3395/6: Galaxienpaar in Leo Minor; 500 mm Cassegrain 3625 mm f/7.2; SBIG STL11K; 270+40+40+40 min LRGB; Bernese Highlands; © 2015 Radek Chromik

History

The galaxy pair NGC 3395/6 was discovered on 7 December 1785 by the German-British astronomer William Herschel with his homemade 18.7 inch f/12.8 reflecting telescope in Slough, England. He listed them under the designations I 116 and I 117. The same night he also encountered NGC 3413 (II 439), NGC 3424 (II 494), and NGC 3430 (I 118). [196, 277, 313] He classified his discoveries based on purely visual impressions, with I = bright nebulae and II = faint nebulae. [269]

The French astronomer Stephane Javelle searched this area of ​​the sky on 17 May 1896 with the 76 cm refractor telescope of the Observatoire de Nice and recorded four other nebulae: IC 2604, IC 2605, IC 2608 and IC 2612, with IC 2605 being a bright node in the galaxy NGC 3995. [196, 277, 315]

Halton Arp divided his «Atlas of Peculiar Galaxies», published in 1966, into groups based on purely morphological criteria. The pair of galaxies here received the designation Arp 270 as a pair of interacting galaxies. [199]

Physical Properties

The interacting galaxy pair NGC 3395/6 is at a distance of 15 to 30 Mpc. [145] According to HyperLEDA [134] they together form the NGC 3430 galaxy group with a total of 15 members, which also includes NGC 3381, NGC 3424, NGC 3430, NGC 3442, IC 2604 and IC 2608. IC 2612 (PGC 32704) has a much higher redshift of z = 0.04452, which corresponds to a heliocentric velocity of about 13400 km/s. This galaxy is far in the background.

NGC 3413
NGC 3413: [147]
NGC 3424
NGC 3424: [147]
NGC 3430
NGC 3430: [147]
IC 2604
IC 2604: [147]
IC 2608
IC 2608: [147]
«Catalogue of Principal Galaxies (PGC)», Paturel et al. 1989 [144]
NameRA [hms]Dec [dms]mTypeDim [']Btot [mag]HRV [km/s]PA [°]
PGC 32390, IC 260410 49 25.7+32 46 29SB1.2 x .914.8168040
PGC 32424, NGC 339510 49 49.4+32 58 51SB M1.7 x .912.5162150
PGC 32434, NGC 339610 49 56.1+32 59 22IB M2.9 x 1.212.61633100
PGC 32464, IC 260810 50 15.4+32 46 06S.9 x .315.6
PGC 32543, NGC 341310 51 21.1+32 46 04L1.8 x .813.1645178
PGC 32584, NGC 342410 51 46.5+32 54 02SB2.7 x .813.21497112
PGC 32614, NGC 3430, IC 261310 52 10.9+32 57 09SB4.1 x 2.212.2158530
PGC 3270410 53 34.3+32 45 01E x 

Finder Chart

The interacting galaxy pair NGC 3395/6 is located in the constellation Leo Minor. The best viewing time is October to June.

Chart Pair of Galaxies NGC 3395/6 (Arp 270)
Pair of Galaxies NGC 3395/6 (Arp 270) in constellation Leo Minor. 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]

Visual Observation

762 mm Aperture: Both galaxies are slightly more elongated than wide and are at right angles to each other, one of which is slightly wider compared to the second. The nuclei are each perceptible as points. — 30" SlipStream-Dobson f/3.3, Hasliberg, 14. 2. 2023, Eduard von Bergen

More Objects Nearby (±15°)

References

134Lyon-Meudon Extragalactic Database (LEDA); leda.univ-lyon1.fr
144Catalogue of Principal Galaxies (PGC); Paturel G., Fouque P., Bottinelli L., Gouguenheim L.; Astron. Astrophys. Suppl. Ser. 80, 299 (1989); cdsarc.unistra.fr/viz-bin/cat/VII/119 (2021-02-18)
145SIMBAD astronomical database; simbad.u-strasbg.fr/simbad
147Aladin Lite; aladin.u-strasbg.fr/AladinLite (2020-12-23)
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
199«Atlas Of Peculiar Galaxies», Halton Arp, 1966; Astrophysical Journal Supplement, vol. 14, p.1 (1966); DOI:10.1086/190147; Bibcode:1966ApJS...14....1A; ned.ipac.caltech.edu/level5/Arp/frames.html
269William Herschel's catalog of Deep Sky objects; messier.seds.org/xtra/similar/herschel.html (2021-12-27)
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; ui.adsabs.harvard.edu/abs/1888MmRAS..49....1D/abstract (2021-04-14)
315«Second Index Catalogue of Nebulae and Clusters of Stars; containing objects found in the years 1895 to 1907, with Notes and Corrections to the New General Catalogue and to the Index Catalogue for 1888–94» Dreyer, J. L. E. (1910); Memoirs of the Royal Astronomical Society. 59: 105–198; Bibcode:1910MmRAS..59..105D; ui.adsabs.harvard.edu/abs/1910MmRAS..59..105D/abstract (2021-04-14)