Minimum aperture for globulars and galaxies

Per Erik Jorde wrote in message ...

First, a small
scope (most scopes, really) typically shows just the central hub of
spiral galaxies, and these are not much differen from ellipticals.

Well, central hub means different things to different people, but
it's true that when a galaxy is at the edge of visibility, you rarely
see the full extent as listed in the catalogs. But the fact remains
that whenever I see a new galaxy -- and most of those are pretty faint
for whatever scope I'm using -- I try to classify it as a spiral,
ellipse, or irregular. I'm certainly wrong sometimes, but I'm right
much more often than not.

I've even seen a fair number of galaxies right at the edge of
averted vision, where I wasn't 100% sure if I was seeing them
at all, but I was 100% sure that if I was, it must be an edge-
on spiral because no elliptical ever has such a thin aspect ratio.

It would be fun to try this particular experiment with the Messier
galaxies and a 60mm scope, but alas, I probably have the classification
of most Messier galaxies buried somewhere in my mind, so it wouldn't
be a fair trial. Maybe if somebody else found them for me, and didn't
tell me which one I was looking at ...

Second, one only has to glance over at neighboring M110 to see an
elliptical galaxy that looks very similar to the naked eye view of M31.

I'm sceptical, but I'll give it a whirl next time I'm under dark skies.

- Tony Flanders