Arp 121 in Cetus

[Mike JW]

Last night I planned to revisit Arp 121 to capture the "wind effect" as described by Dr Arp.  The interacting galaxy pair are about 230 million lyrs away (or more).

The circular galaxy PGC 3553, (the uppermost galaxy) is classified as SO (lenticular) and does not appear to be affected by the interactions. Does this suggest it is considerably more massive than its partner (PGC 3547) which has been well and truly churned up by the gravitational interactions, hence classified as Sa peculiar.

Arp grouped this pairing in Elliptical and elliptical like galaxies, close to and perturbing spirals. Equally this pair could be classed in his "wind effect group".  

Mike

[elpajare]

It is a challenge photograph. The plume towards the S described by Kanipe & Webb can be intuited.
And the magnitude 14/15 makes them even more difficult. Congratulations Mike

[Mike JW]

Thanks Elpajare. Much appreciate your extra information in replies as well as in your postings. Mike