I used my 4-/8-inch combo bent refractor. I noticed a thin crescent moon about to set over a nearby cliff, so I trained the scope on it and watched one rock cover over the other, with some trees on the cliff edge silloutetted in the earthshine. It stayed warm through most of the night, and pretty dark at 21.62 SQML. Transparency was 4.5/5, but after 2pm I could smell wetness in the air, and the transparency started to fail, the SQML reading went to 21.2. The setting circles still don't work on my MaxLoad, likely because of insufficient resolution, so I star hopped. I decided to view what this scope and night vision do best, HII regions, so I pulled out the Vogel's Sharpless guide (from which many of the photos were taken) and started from the top.
IC 4628: I observed this a few years ago from Willow Springs using a 10-inch and HBeta filter. It was much fainter then. Now with just the 4-inch and not quite astronomical dark, I could see the bright sweeping arc, streamers falling from it toward an open cluster, and a very bright knot floating above it. This time I could see faint clouds drifting away from these two main nebula, something only visible in photos.
Sh2-1: With 4-inch and 3nm, a vague haze to the south of Pi Scorpii, with a pillar of nebulosity hooking up north along the west edge of the FOV. The edges of the nebulosity are brighter and sharper along the sides near the star. With 8-inch can more clearly see a bifircation of the nebula to the south west, and the edges away from the star have more diffuse nebula coming off the edges. Reflection nebula ~650 ly distant.
Sh2-2: Very vague large cloud which appears as a mottling of the darkness, surrounding a triangle of similar magnitude stars. Overall it has the appearance of a pair of lungs, with a dark lane running N-S. Vogel notes: "This HII region is a wind blown bubble surrounding the O6.5 Ia star and prominent X-ray eclipsing binary HD 153919 and is in the same direction (but much further) as the star cluster NGC 6281." 4-inch 3nm.
NGC 6256: This globular cluster was nearby so I had a look. With the 8-inch unfiltered, the GC had an intensely bright and concentrated center, with a dense ball of stars surrounding that, and vast streams of stars radiating from it in all directions. What's more there were so many stars in the intensely rich 2-degree FOV. Stunning. Globulars will be my next project after Sharpless...
Sh2-3: Relatively small, viewed in the 8-inch. It has an S-shaped appearance starting with a faint coil of nebulosity around a bright star, then wending to the south where there is a thicker and brighter section. The sourthern edge is deliniated by a bright streak. In the 4-inch with a wider field, there is a near circle of nebulosity surronding it, brightest to the southwest. Vogel notes this object is 4.5pc in size, and "is ionised by an O6 V star, most likely CGO 439."
Sh2-4: Appears as a bright knot in a wider sweep of nebulosity, quite easy in the 4-inch. It is said to be ionized by and physically associated with the stars of open cluster Havlen-Moffat 1, which lies ~15' to the northwest. In this Aladin screen capture HM1 is under the reticle and the nebula is to the southwest. In the scope, HM1 appeared as a small clump of stars, much like many others in the field, and it didn't draw much attention. The nebula is also known as RCW 121. The nebula is in the Sagittarius Arm of the Milky Way,
Sh2-5: Large, fairly bright, no discernable shape other than vague cloud forms. In the southwest section the nebulosity seems to sweep out in a fan shape from one star. Also ionized by HM1.
Sh2-6: NGC 6302, The Bug Nebula. With the 4-inch it was very small in the 4-degree field, but easily seen and already showing an S-curve eminating from a bright central region. In the 8-inch and using a 20mm eyepiece to increase the image scale, unfiltered, the amount of detail seen was stunning. Both wings from the bright center were bifurcated or forked, and accentuated with bright knots, and there were many fine filaments woven throughout these wings.
Sh2-7: Long mottled streak eminating to the southwest from Delta Scorpii, breaking up into spreading filaments near a group of three bright stars. Best in the wide field.
Sh2-8: NGC 6334, Cat's Paw. Having never observed this area before, I was completely shocked at the amount and brightness of nebulocity here. The amazing nebula came alive with the 8-inch and 3nm. Everything was mottled and full of detail! Each "toe" was a a bright puff of nebulosity and mottled in its own way. The southern one spread in a fan shape from a bright star and seemed rippled with bow shocks. The southwest was dense and closely mottled, and the northern was a complex of streamers and dense curds. The northwest fragment slowly diffused, as if wind blown, to the west. A very remarkable area. With the wider FOV in the 4-inch there were faint trails nebulosity which seemed to connect it to other bright nearby HII regions NGC 6357 and Sh2-10.
Sh2-10: Three degrees WNW of the Cat's Paw, it is a large mottled cloud seemingly centered on a relatively bright star in the field. Vogel notes the nebula "is in the same direction as the Wolf-Rayet star WR 88." Best in the 4-inch.
Sh2-11: = NGC 6357, and with the 4-inch I can get Sh2-8, -10, and -11 in the same dramatic field. It has three main large bright mottled knots and a C-shaped curved structure with many fine filaments reaching up from it. The center is sprinkled with many small stars (Pismis 24 open cluster).
Sh2-12: A very large, bean shaped cloud with ragged edges and dense mottling, curved around a bright star -- which has several fainter stars densely packed around it. This is open cluster NGC 6383. Vogel notes that Sh2-12 is ionised by the binary O-star (O7V + O7V) HD 159176, which is in the star cluster NGC 6383, which in turn is in Sgr OB1. M6 the Butterfly Cluster is in the same FOV with the 4-inch.
Sh2-13: A very large cloud mottled cloud centered on a star, with the denser / brighter region forming a cap to the north. A larger field of nebulosity is closeby to the southwest.
Sh2-15: A mainly round nebula, darker in the middle and with streams of faint nebulosity escaping from the weak northeast wall. 8-inch shows the bright, thick south eastern arc and dark nebula intruding in the western section, a club-like clound and a very dark hole. The center of the nebula was crennlated with dark lobes. Vogel: "This HII region is ionised by the O8 V star HD 161853 and is part of the S15-S20 complex of HII regions. This region is also called W25 or Gum 69."
At this point I took a break and looked at the Milky Way with my night vision at 1x and 3x using my mirror mount. Simply stunning. The dark nebula were especially prominent, and in some sections seemed to be an evaporating fog off the stream of the Milky Way. Using a 5nm filter I traced all the nebulous clouds from the southern horizon through Cygnus and into Cepheus. What struck me was seeing a bridge of faint nebulosity which seemed to connect Sh2-119 behind the North American Nebula all the way to IC 1396 in Cepheus. This photo I found online (by Kotz Tar) kind of shows hints of the nebulosity, in red, but for me it was a very obvious, if faint, stream that very much seemed to connect the two. It wasn't just the star stream, it was definitely nebulous. This image also shows the Veil, including Pickering's Triangle, in the same field -- which I could see too. Pretty amazing.
I also saw a very large round nebula of around 10-degrees diameter centered on a bright star north of Scorpio's claws. The brighter portions are Sh2-27 & LBN 30. I observed these with the 4-inch at Spring CalStar, but only in pieces since the field of view was too small. Now with 1x I could see Sh2-27 and LBN30 as brightenings in a much larger round cloud of mottled nebulosity. (Image Project Nightflight)
Sh2-17: Very faint, small knot of nebula in a dense star field, difficult to find as there's no brighter stars nearby.
Sh2-18 -19: Faint nebula which sprouts from two stars in a fan shape to the north, with a faint ragged flap drifting off to the northeast.
Sh2-20: Very faint, small, forked knot of nebulosity, also in a dense field of stars.
Sh2-21: Very faint, very small, irregular round glow, difficult. Took a long time to find and needed the 8-inch to bring it out. Vogel says "this HII region is located near the galactic nucleus and is associated with a giant molecular cloud and two star clusters." 8000pc distant.
Sh2-22: Large, thick parenthesis of nebula, very strongly mottled, surrounding a bright star. Vogel: "This is a ring nebula surrounding the O-star HD 162978." (image Jim Brunell)
Sh2-25: Lagoon Nebula. What can be said but so much detail, so much to be seen. Dark nebula smoking, a fizz of nebula round it, with arcs and bridges. Vogel: "The Lagoon nebula (M8 = NGC 6523-NGC 6530) is a large HII region mainly ionized by two O-class stars, 9 Sagitarii [O4V((f))] and HD 165052 (O6.5V + O7.5V). It is embedded within a molecular cloud which extends to the star cluster NGC 6530. Within M8’s core lies a distinctive bipolar nebula called the Hourglass, a blister-type HII region which has been produced by the O7.5V star Herschel 36 (Her 36). Note that RCW 146 also includes Gum 75 (Sh 2-29, Sh 2-31, and Sh 2-32), the nebula complex next to the Lagoon nebula....In 2003, an infrared cluster was reported in NGC 6559, which is part of Sh 2-29. Sh 2-29, Sh 2-31, and Sh 2-32 all appear to be part of the same nebula complex although the associated CO elocities suggest that these objects may have quite different distances."
Sh2-33: Extremely dim, ripples of nebulsity seen only when moving the scope, very large, in the 4-inch. Vogel: "The faint red glow of the nearby molecular cloud MBM 38."
Sh2-34: Patchy nebula above the Lagoon, like a broken-up contrail.
Sh2-37: A bright, raggedly round nebula centered on a bright star. It is separated by a dark lane from a very large curving stream of nebulosity which is Sh2-35, which is fractured and crazed with many wisps of dark nebula. Vogel: "Sh 2-35 and Sh 2-37 are associated with a 130 thousand solar mass giant molecular cloud at a distance of 1800 pc and appear to be part of the Sagittarius OB7 association. Sh 2-37 is visible through a hole in this molecular cloud. This is a very active star formation region. Sh 2-37 is also known as IC 1283/1284 and the powerful radio source W34. Sharpless notes that this HII region is associated with the bright stars HD 167722 (B5), HD 167815 (B2) and HD 313098 (B5)."
Sh2-36: Extremely faint, looks like streamers hanging down from a cloud when it rains. Vogel: "The faint rusty red glow of nearby giant molecular cloud MBM 39."
Sh2-38: Small, extremely faint haze, in a dipper-like asterism, 8-inch. Vogel: "This appears to be the same as the reflection nebula VdB 114 surrounding the B8/B9Ib star HD 165811. It shows a strong (if small) image in hydrogen-alpha, however, so perhaps there is both emission and reflection in this little
nebula. Sh 2-38, Sh 2-40, Sh-41 and Sh 2-42 all appear to be embedded in the Sagittarius OB4 association."
Sh2-39 & -41: Sh2-41 is a very large glow streaming through very dark and dramatic dark nebulae B92 & 92 (which are white in this negative image). Sh2-39 is on the southern edge of Sh2-41and appears as a faint nebulous patch.
Sh2-40: faint, bifurcated faint nebula. Two close stars sprout the brighter wing of the nebula which sweeps to the south. The norther nebula is fainter and is fan shaped, with the wider section to the west. Vogel: "A look at this region in hydrogen-alpha shows that Sh 2-40 appears to be several bright knots of nebulosity extending north from the much larger nebula Sh 2-41. Sh 2-40 lies in the same direction as the powerful radio source W33, but the distance estimate for W33 is about 4000 pc. So there seem to be two objects here in the same field of view, one visible only at radio frequencies. Sh 2-38, Sh 2-40, Sh-41 and Sh 2-42 all appear to be embedded in the Sagittarius OB4 association. The massive protostellar object IRAS 18089-1732 is in the same area of sky but is located at a distance of 3600 pc.
Sh2-42: I tried very hard for this one, including using 8-inch with the 20mm eyepiece and flipping through all the filters. No luck. It is a PNe and I probably would get it with an OIII filter.
Transparency began to suffer at around 2am, I could smell wetness in the air, and the SQML readings were 21.2.
Sh2-43: Fairly faint, irregularly round cloud, just to the west of a bright star, seen in both 4-inch and 8-inch. Vogel: "This faint diffuse nebula is in the same location as the suspected supernova remnant GAL 013.1-00.5 and appears to be located in an empty region bordered by the OB regions SGR OB1, SGR OB7 and SCT OB3. There is a 0.3 degree difference between the positions of RCW 156 and Sh 2-43. Sharpless gives the diameter of Sh 2-43 as 15 minutes = 0.25 degrees. RCW gives the diameter of RCW 156 as 50x50 minutes. These objects may not be part of the same nebula, but they are clearly very close in the sky."
Sh2-44: Very large, pretty bright, strongly mottled round cloud, with many stars and dark patches within. Vogel: "This nebula is connected to the Oe star HD 167633 (which Humphreys connects to the Serpens OB1 association) and may be part of the Scutum supershell in the inner galaxy."
Sh2-45: M17, the Omega Nebula. Wow! Tons of detail, mottling, etc. Too much to describe. Vogel: This is M17, the Omega nebula, also called W38, the Swan nebula, and the Lobster nebula among other names. M17 is ionised by an O4V-O4V double star system (Kleinmann's star) at the core of the massive young cluster NGC 6618 (about one million years old), which contains over 800 stars, including 2 O5V star systems and 100 stars hotter than B9 (by comparison, Orion has 8 stars hotter than B9). The total ultraviolet flux is about 25 times higher than for Orion. A large part of the nebula is hidden by a dark dust lane the runs near the central cluster and splits the main visible nebula from two attached nebulae on the other side of the dust lane (IC 4706 and IC 4707). M17 is a blister on the side of a much larger
giant molecular cloud and star formation region (M17SW) that contains 30 thousand solar masses of molecular hydrogen.
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