2/9 & 4/9: M57 and some other sketches

After a miserable August with a grand total of 0 nights in the observatory, September started off rather well. On the 2nd the skies were reasonably transparent and quite steady. I started with a few galaxies, most of which I haven't observed before.

NGC5322 9/2/2008 21:15 UT; Pickering 8, NELM 5.5, SQM 20.7
APM 16" Mak-Cass, 17T4, 235X

Stellar core at 150x becoming semi-stellar at 235x. Reasonably bright elliptical halo with one foreground star immediately to S of galaxy and a second somewhat more removed from the halo to the E. Lots of very dim field stars.



NGC5473 9/2/2008 21:35 UT; Pickering 8, NELM 5.5, SQM 20.7
APM 16" Mak-Cass, 17mm Nagler T4, 235X

Smaller and dimmer than NGC5322, but in a considerably brighter field. Semi-stellar core with somewhat elongated halo -- but the orientation kept flipping.

NGC5474 9/2/2008 22:00 UT; Pickering 8, NELM 5.5, SQM 20.7
APM 16" Mak-Cass, 26mm Nagler T5, 150X

Much larger than NGC5322 or 5473, but also much (much) dimmer. Averted-only at 235x, just barely direct at 150x, and further brightening all the way down to 75x -- but you still had to look for it. Detail, however, becomes more difficult at lower powers, with the sweet-spot somewhere between 100x and 150x.

Hints of 2 clumps to NNE -- with further study one tightens to a foreground star and the other appears to be the core -- although it's right at the edge of the visible halo.



A couple of nights later it was clear again, and with the steadiest skies I've yet seen in Ireland. (I'm so used to looking for the moving diffraction ring that for a minute I didn't realize I was looking at the second instead of the first, which was quite stable.)

Transparency was somewhat improved, although partly cloudy so the SQM number was unchanged.

M57 Ring Nebula 9/4/2008 22:00 UT; Pickering 9, NELM 6, SQM 20.7
APM 16" Mak-Cass, 6.7mm S4000 UWA, 600X

Crisp stars at 600x (a first), although field feels a bit cramped at this image scale. Still, dim field stars and ring central star easier at this mag. Most of the observation was carried out at the higher magnification, with the field for the sketch drawn at 450x.

Central star perhaps 20% in averted. The brighter sections of the ring (at each end of the minor axis) also show some clumping which attempts to resolve into stars at perhaps the same 20% rate, but I believe this to be an illusion. I did not note the star embedded in the W end of the ring. Of the faint field stars I recorded the four stars along the NW perimeter (mag 14.7, 15.0, 15.3 and 15.7), but did not notice that the eastern-most was a double (w/15.0 companion). I also recorded mag 15.4 and 15.6 stars to the NE.



NGC6210 Turtle Nebula 9/4/2008 22:20 UT; Pickering 9, NELM 6, SQM 20.7
APM 16" Mak-Cass, 6.7mm S4000 UWA, 600X

Woah, that's really cool in excellent seeing. Central ball is quite bright, with a slightly dimmer edge. This edge then has 4 dimmer "ears" at not quite 90° increments; the WSW ear perhaps the most prominent and the ENE ear the least pointy.



NGC6058 9/4/2008 22:35 UT; Pickering 9, NELM 6, SQM 20.7
APM 16" Mak-Cass, 8.8mm S4000 UWA, 450X

Much dimmer than expected, and a bit larger as well. Responds well to UHC and OIII at 235x, but of limited use at 300x and above. Filters also knock out the otherwise direct-vision central star.

Just for kicks I tried the OIII at 600x -- the field goes essentially black with the PN popping out in averted vision only under motion. Interesting effect.

NGC6543 9/4/2008 22:50 UT; Pickering 9, NELM 6, SQM 20.7
APM 16" Mak-Cass, 6.7mm S4000 UWA, 600X

Very bright but takes magnification exceedingly well. Moderate blue-green color at 235x fading down to essentially no color at 600x.

At higher powers the shape is very similar to M57, but with less annularity, a more prominent central star and an averted-vision faint outer shell with fringed edges. Inner shell somewhat mottled. I should have sketched it -- it looks nothing like the photographs to the eye.

-- Jeff.

Super report Jeff.
I really like that sketch of M57!

Great sketches Jeff, ditto for M57, love the detail.

Thanks Michael and Paul.

I think that M57 might be one of my better efforts to date.

Have you gotten any dark time in on your big CAT this season Michael? I couldn't believe how good the seeing was on the 4th; too bad there weren't any planets any better placed.

Cheers,
-- Jeff.

Unfortunatley, I've only got to use it about 3-4 times since I got it and even then, it was just a few brief moments