not just for nebula anymore

The star party I planned to attend later this week is being disrupted by the remnants of a tropical storm, with risks of showers and thunderstorms.  Tuesday night (the 16th) seemed the only night I could get away for a darker sky, but being a weekday meant fighting traffic in all directions.  I ended up going to Henry Coe as it's relatively close.

I have been working to recover the 8-inch folded refractor I bought almost a year ago and have made some progress (correcting a flipped objective, adjusting the flat mirror height to spec.) but it still does not provide good clean images.  So instead of bringing it out, I brought my C8, intending to use it in prime focus mode to view star clusters and galaxies.  With prime focus in the C8 I have 78x magnification and 0.5-degree field of view (I couldn't reach focus with my corrector, I need to try a different diagonal).  Unfiltered the whole night.  It fit the night pretty well, and I had been meaning to try out this combination for several months anyway.  Since the Milky Way is slipping into the western sky, and the west is completely washed out at Henry Coe by light pollution, it was no night to try nebula.  The C8 was the best choice, and I'm glad I got to know its capabilities with night vision.

I was the first in the lot and Richard and Philip arrived at sunset.  Richard with a 5-inch refractor and Philip with a lovely 17.5-inch dob.  Once dark I ran through alignment on the AVX mount with Mirach as the last calibration star, and I immediately noticed NGC 404, Mirach's ghost, pretty bright oval with a bright central core.  It is an isolated dwarf lenticular galaxy around 10 mly distant, just outside our local group.  Off to a good start.

I ran through a number of open clusters to start, such as M52, NGC 129, and so on.  NGC 7789, Caroline's Rose, was especially beautiful and really does look like a rose, with semi-circular loops of bright and faint stars expanding from the center and folding into each other.  SQML was 20.4 once fully dark.

I then went through mostly galaxies, and I was very impressed with what I could see.  I had the sense I was seeing in the C8+NV what I had seen with my 20-inch from much darker skies.  

NGC 7331: Bright round core, like a ball floating on a frisbee, an effect of the contrast between the very elongated halo and subtle dark lanes on the near-side close to the core.  Flea NGC 7340 noticed immediately, well away from the galaxy, with NGC 7335 seen with slightly more effort, and smaller, fainter NGC 7336 noticed with considerably more effort.  NGC 7336 not noticed at all, nor the supernova, nor the very tiny NGC 7326 or NGC 7325 on the other side of the galaxy than the fleas.  Philip tried with his 17.5-inch, and I could pick out NGC 7340 pretty well, but not any others -- I may not have been dark adapted because of the night vision device.  Richard was able to see the three I mentioned.

Stephen's Quintet: 3 galaxies (NGC 7318, 7319, 7320) seen with certainty as in a triangle, with a sense of the area inside and around the triangle lumpenly brighter from the surrounding skies.  7318 was the brightest, elongated with a bright core, the other two were small soft irregular glows.

NGC 7549, NGC 7550, NGC 7547: Three galaxies forming an isosceles triangle.  7459 was a small non-stellar oval glow, oriented N-S next to a bright star.  7550 was fairly evenly bright, larger round glow.  7547 was small, elongated 3:1 ENE-WSW, with a bright stellar core.  

NGC 40's bright irregularly round shell had brighter edges on either side of the outer shell, like parenthesis.  There was a gap between the bright central star and the shell, and outflows of nebula escaping the poles.  Most curiously, these outburst portions positively shimmered -- not from seeing, but as if by variations in light pulses.  I observed this twice at different times during the night, at different elevations, and the effect was the same.  

NGC 1501: Prominent central star, faint round halo with crisp edges, forms a subtly irregularly round circle, with soft mottling inside the halo.

NGC 382 is in the center of a 14-galaxy group, most aligned in a N-S string.  I drew 5 galaxies in my sketchbook: 382, 380, 379, 385, 384, though a couple of what I took to be stars might have been small galaxies, but I didn't count those.  They all appeared as small elliptical glows of varying size, brightness, and orientation, and it was neat to see them in a string like that.

IC 342: a soft, moderately large round glow, seen best with gain turned down low.  I sense some swirling effect in the mottling, especially near the center bright stellar core, but it is very subtle.  NV does not do well with face-on galaxies.

NGC 891: This was very large, a bit more than the FOV, and very ghostly, seeming to float in the dense field of stars.  Faint, long, with a prominent dark lane down the center.  

NGC 910 group: Just a half degree to the southeast from NGC 891 is NGC 910 and friends, a string of five brighter NGC galaxies, plus a couple more very faint and small NGC and MCGs.  910 was the brightest by far, then leading north like breadcrumbs were 911, 909, 906, and 914 off to one side.  These all appeared as small elliptical glows in various orientations.

NGC 80 group: Another cluster of galaxies of which I saw eight: 80, 83, 90, 93, 79, 85, 86, 96 all as small elliptical glows, except for 90 which was slightly mottled and round.

NGC 772: This is a disrupted spiral and appeared so: a bright core off-center to a diffuse comma-shaped halo with a long bright arm, which I could clearly see, to the north.  Smaller, fainter elliptical NGC 770 was close by to the southwest. 

NGC 200 and others: Another string of galaxies, this time seven in the field of view (193, 204, 199, 194, 200, 198, 182), all pretty bright oval and round glows except for 199 which was smaller and fainter.

AGC 426, Perseus Galaxy Cluster: when centered on NGC 1272, I can see more than 15 galaxies in the field with direct vision, and a few more with averted vision.  Several bright ones, then smaller non-stellar glows appear.  This view more than anything convinces me the night vision device really does triple the effective aperture!

NGC 1023 / 1023A: One of the more dramatic galaxies seen.  Very large, bright, very long arms extending beyond the FOV, and swirly dark nebula around the core.  The eastern tip had a brightening which is elongated at a slight angle than the main galaxy, this is 1023A, its satellite galaxy.  Too bad Jamie wasn't there to have a look!

It was at this point I remembered how night vision does particularly well with flat galaxies, so I pulled out Alvin Huey's Flat Galaxy Observing Guide and observed some I hadn't looked at before:

NGC 100: Lovely long galaxy at least 8:1 NE-SW, with a bright central core and a halo which gently tapers to very fine tips.  Vmag 13.9, size 5.4 x 0.6'.

NGC 522: Small but bright, with a very bright core and long tapering tips, 6:1 NE-SW.  A string of 3 fine stars just north of the galaxy.  Bmag 13.9b, size 2.7 x 0.4'.  Did not notice IC 102.

IC 194: Difficult, very faint, small but very extended streak nearly N-S, slightly brighter round core.  Mag 15.2p, size 1.4 x 0.2'.

IC 176: Very difficult, extremely faint, needed to check the star pattern in the guide to locate it.  Small 4:1 E-W glow with a very faintly brighter core.

NGC 973, with IC 1815 in field: 193 looks like a smaller version of NGC 891, edge-on and bisected by a dark lane, 6:1 NE-SW, Mag 13.6p, size 3.7 x 0.6'.  IC 1815 was a small out-of-round glow with a brighter core.

NGC 1110: Extremely faint, needed to play with the gain setting to detect it: weak glow NNE-SSW, 5:1, very slightly brighter central region and diffuse, very faint tips.  Mag. 15.0 2.8 x 0.5' 

NGC 1145: Fairly easily seen, in an "L" shape asterism of three equal magnitude stars, 6:1 NE-SW, it has a compact bright core, and the halo is mottled -- I have the sense it is slightly inclined towards us showing some spiral structure.  Mag 13.6b 3.2 x 0.5' 

NGC 1163: Very faint, lays off of a triangle asterism.  Brighter bulging core region quickly fading to sharp tips.  Mag 14.7b, size 2.8 x 0.3' 

NGC 1247: Pretty bright, very bright core, mottled inner halo, diffuse tips, 6:1 ENE-WSW.  Mag. 13.5b 3.3 x 0.5'.

IC 2098: Extremely faint, small, 6:1 E-W, with a slightly brighter round core which bulges from the halo.  Mag 14.5, size 2.5 x 0.2' 

NGC 925: face-on barred spiral, appeared as a fairly large, faint mottled glow with a small bright core and a brighter smudge in the halo glow extending E-W from the core.   

NGC 253: Probably the sight of the night: Gigantic galaxy filling more than the field of view, very mottled halo with swirls of dark nebula around the core.