Some recently finished drawings

Everywhere N is up and W is right.


Below: M99 (16", 225x)

http://3.bp.blogspot.com/-6E84Prn5He...1+finished.jpg


Below: M100 with NGC 4322, -3, and -8 (16", 225x)

http://1.bp.blogspot.com/-pq4evHzuHe...+225x+CSSP.jpg


Below: M104 (16", 45 and 225x, some features are illusory)

http://2.bp.blogspot.com/-WcjRZ4cuv3...x+CSSP+IVM.jpg


Below: NGC 253 (12" SCT, 125 and 230x)

http://3.bp.blogspot.com/-XN4KsekG7s...2011-11-01.jpg


Below: NGC 3184 with star clouds NGC 3180 and 3181 (12" SCT, 230x)

http://3.bp.blogspot.com/-BhTG3c4q8G...2011-11-05.jpg

Very impressive collection, Ivan. I was comparing your drawings of M99 and M100 with a couple I did from my backyard last year, especially since we were using similar magnifications (you 225x vs my 207x). While generally there is good agreement between our two interpretations, you are outperforming me in the fine detail department. I'm curious, the detail you are picking up near the cores of both galaxies are probably only a few arc seconds across. Are you using high magnification to make out this detail and then incorporating it in your drawing?

Thanks, Mark - yes, the littlest arcs are about 7 (in M99) and 15 (M100) arcsec long, and the resolution in that central area was probably no worse than 4", i.e. probably seeing-limited. I usually combine views at different magnifications and then indicate the range on the sketch; these M99 and M100 though are single 225x views. Their cores, however, are something like the Cat's Eye planetary: they are so bright that pretty much the tiniest details that the atmosphere and optics can resolve are visible. Switching from the faint but large outer features on black background to the bright but small inner features on bright background requires (for me) a conscious adjustment of vision. The drawing (especially of M99) does not convey the magnitude of this rise in brightness well, in part because it might not otherwise fit in the dynamic range of a computer screen.

Hi Ivan

A great Job Ivan!!! Very interesting Observations and sketches..

CS Hajü
www.astromerk.de