Testing VC200L-Barnard's galaxy and M104

[allan gould]

Im still getting used to the VC200L and its quirks.
Ive found that I dont mind the Vixen rack and pinion focuser as it holds the cameras stady and is quite smooth. The thing with this scope is collimation, collimation, collimation and focusing. It really can mess with star shapes if you collimation is off or you focus is not spot on.
The bahtinov mask certainly makes this task easier and I can see why quite a few got frustrated with the scope. But it does hold focus and collimation very well from night to night.
Im quite surprised by the optics as when I look closely at M104 (20x5min shots with QHY8) I can see detail coming up in the plane of the galaxy as well as the dust lanes. Not quite as sharp as the 10" with QSI but thats a completely different system.
I then spun over to Barnard's Galaxy as its always intrigued me and managed to get 20x5min with the QHY8 camera. I wasnt even sure I was in the right position and had to rely entirely on the pointing capabilities of the Losmandy mount. Only after processing was I able to see this faint ghostly cloud. Anyway the purpose of the exercise was to get round stars - Im almost there just a bit more to go and then Ill be sattisfied. The other pleasure of this scope is the Vixen reducer to get it to f6.4. Really nice field and its just as flat as the uncorrected field. Just got to love that.
Anyway comments welcomed.

[madbadgalaxyman (Robert)]

Yeah, Barnard's Galaxy is LSB, ain't it!

It is probably more typical of dwarf irregular galaxies than a few high surface brightness examples that are undergoing a recent burst of star formation.

The Luminosity(absolute magnitude) vs Surface Brightness relation for galaxies indicates that galaxies keep getting lower in surface brightness, the less luminous the galaxy is.
At the extreme, we find tiny galaxies with only a smattering of stars, galaxies which are no more luminous than the average globular star cluster, but which still seem to be able to hold themselves together, despite the fact that they have hardly any stars. (hence the existence (it is thought) of the mysterious "dark matter".....sometimes it requires hundreds of times as much dark matter as luminous matter to gravitationally hold a very low luminosity dwarf irregular together)

Does dark matter exist?. Well, I asked a well known expert on how gravity functions in holding a galaxy together, and he said to me that "that is where the data leads", while admitting that there could be some other explanation for the fact that very low luminosity dwarf galaxies seem to be composed of hardly any stars........ yet they do not fly apart due to the individual velocities of their stars.