NGC 5291, a lenticular galaxy in approx. 200 million light-years distance is part of the galaxy cluster Abell 3574 in the same distance. It is interacting with another galaxy NGC 5291B, a dwarf galaxy, also named Seashell galaxy, seperated by 39 000 light years. After the galaxy fly-by some 100 million light years ago a huge HI ring formed and expanded in the intergalactic collision, spanning close to 600 000 light-years. The visible blueish ejecta tails are spanning to approx. 100 000 light-years.
Undergoing a very recent starburst and showing evidences for the presence of Wolf-Rayet stars, the surrounding dwarf galaxies stand out among Blue Compact Dwarf Galaxies because of its high, more than half-solar, metallicity, similar to that of tidal dwarf galaxies.
Find more background information on this interacting galaxy pair and a Spitzer image here: 1 2 3 4 5
LRGB (660-120-120-120 min) total 17 h, north is up, seeing 0.8-1.2 arc-sec
80cm f/7 Astrooptik Keller cassegrain, FLI PL-16803, Astrodon Gen2 filters, Prompt 7 CTIO Chile
Processing: Johannes Schedler APOD on Nov 21, 2015
Find the full frame image in 25/64% size below
Find a crop on NGC5291 in 50/80% size below
Find a crop on the south-eastern situated galaxy group (NGC5298, PGC48950, PGC159482, PGC48956,...) in 60/80% size below