Astrodvorek Kamenne Zehrovice

Shell galaxies, NGC 474, 470 a 467 ,  Arp 227



This interesting group (also known as the Pisces Galaxy Trio) is located at distance of about 100 million light-years (NGC 467 on the right even 250 MLY). The largest galaxy NGC474 (diameter more than 200 kLY, to the left) is a classic shell galaxy interacting with smaller neighbor blue spiral NGC470. Surprisingly the third galaxy NGC467 also shows some hints of shells. In the background we can also find some much more distant galaxies, already the little face-on spiral near the left edge (PGC 1252050) is situated some billion light-years from Earth. The most distant object in the picture (marked by an arrow to the right) is quasar with redshift z = 4.23 (light travel time over 12 billion years). Total exposure time (with 8" f/4 Newton): 16 hours !


Optics:       NoName Newton 192/800
                   +GPU c.c.

amera:    Atik 428EX
Filters:        LRGB Baader

Mount:      SW AZEQ-5
Guider:       Lacerta MGEN

Exposure:  115x5 min. (L)
x5 min. (R, G, B each), bin 2x2
Software:  PixInsight, Photoshop
12.9. 2016