This comment is about 24 hrs late, but Ann, your mention of Burnham’s Celestial Handbook (1966)
back in the first comment in this thread prompted me to retrieve my set which I haven’t taken off the shelf in years. I couldn’t confirm your recollection as to it saying what you thought you remembered about the two galaxies having similar masses, but I found this paragraph (beginning on page 371) about NGC 5195 to be of interest:
“Conspicuous in the small telescope, this satellite system gives the appearance of being attached to the north end of the spiral arm of M51. Evidently it does not lie exactly in the plane of the big spiral, since dust lanes of the M51 arm may be seen crossing in front of it. There are also some dust patches on the opposite side, believed to be directly associated with the smaller galaxy itself. The classification of this peculiar system is uncertain. In the Hubble Atlas of Galaxies, A.Sandage (1961) refers to it as an irregular galaxy of the M82 type. Some long-exposure photographs show faint outer filaments which seem to suggest the structure of an incipient barred spiral. On the other hand E.M. and G.R.Burbidge (1964) have classed it as an S0 system. If the superimposed dust clouds and the obscuring matter connected with the arm of M51 were removed, the system would probably resemble an elliptical galaxy. Its light is much redder than that of M51, and true resolution does not appear to have been achieved with any present telescope. The corrected radial velocities of the two objects are fairly comparable; 340 and 390 miles per second in recession.”
With today’s (now yesterday’s) improved image of NGC 5195 a few stars can be resolved, but not near as many as in big bubba, M51. It’s redder color and its faster recessional motion made me wonder if perhaps this galaxy wasn’t in fact connected to M51 at all. It does have a slightly distorted, sort of tri-oval shape, and Wikipedia mentioned the presence of a tidal bridge between the pair, so they must if fact be connected. The color difference is striking however.
Just as zero is not equal to infinity, everything coming from nothing is illogical.