N206 at low magnification with a UHC filter is magnificent! It appears as if the entire superbubble flows out from NGC 2018, at the southeastern side, in a more or less northwestern direction. You can immediately see that you are looking at a complex superbubble! NGC 2018 is a gorgeous, brightly glowing, circular patch of pearly light with beautifully crisp edges. Two extensions flow from it, one north and the other south, both curving westwards. They look like a bow wave, as if NGC 2018 were sailing eastwards through space! As anyone who has ever been on a boat knows, bow waves define the outer limits of a wake, the wave pattern on the water surface downstream of the boat. In this case, NGC 2018’s nebulous bow wave helps define the superbubble whose nebulosity flows out like a wake with a round, very uneven, and smudgy nebulosity, with some brighter patches having lovely, wavy curves to them. Dark patches that look like dust lanes are scattered around randomly. Very unusual… but then again, everything about a superbubble is unusual!

The sides of the superbubble are very interesting. The north-western side fades into a lovely starry nothingness, except for a rare Wolf Rayet bubble that lies on its periphery. The northern side appears as a fractured and wispy arc of very faint nebulosity; it looks like an almost-transparent strand of faintly glowing light melting into the background.

And along the southern and eastern sides, one finds three nebulous patches strung out along the superbubble’s periphery – N206B = BSDL 2120 (the largest of the three), BSDL 2048 (the second largest), and BSDL 2005 (the smallest and faintest).

Beautiful and complex N206 is rarely imaged. Credit: NOAO

16″ at 228x: The stars of LH 69 appear to stream through and out from beautiful NGC 2018, flowing in a NW-SE scattering of about 3 dozen resolved bright and faint stars against a background of both unresolved stars and nebulosity. The brightest stars are arranged in three distinct groupings. Just west of NGC 2018 a nice trio of stars form a slender triangle, the apex pointing north. The easternmost and slightly bloated mag 11.5 “star” of this triangle’s base is a massive compact cluster R113, containing several O-type stars!

The second grouping lies northwest of this grouping, and it forms an unusual little asterism, looking like an off-kilter Delphinus, its ε Del equivalent (HD 269660) a lovely mag 11 sparkler that is also the ionizing star. The third grouping lies northwest of the little faux dolphin, and it contains a few small faint stars along with a nice “pair” of stars, mag 12.9 Wolf-Rayet star Brey 44 and mag 12.6 HD 269656, an OB-type star that lies just NNW of it.

16″ at 228x: Lying to the southwest of LH 69, the smaller LH 66 doesn’t have any bright stars for us, but even so its faint scattering of stars is pleasantly noticeable. Three patches of faint foggy nebulosity are strung out in a 6′ line oriented NW-SE along the superbubble’s SW periphery, and two of them lie within LH 66 – the northernmost patch BSDL 2005, which it has two mag 14 resolved stars embedded almost dead centre and BSDL 2048 to its southwest, a faint roundish patch with three faint members of LH 66 embedded in it. The southernmost patch is N206B = BSDL 2120 and it appears as a faint, elongated E-W patch of foggy mist with two faint stars embedded in it.

16″ at 228x: Without a filter NGC 2018 is very conspicuous as a bright, circular patch, 1′ in diameter with hazy edges, and with a number of LH 69’s stars scattered over it. The faint smudgy extensions flow north and south, curving westwards. The southern extension is slightly brighter than the northern one (in which SNR B0532-71.0 is buried). The contrast gain with the UHC filter is tremendous! The nebulosity appears smooth with beautifully crisp edges. The two extensions are far more prominent, albeit still rather faint and diaphanous, and they extend the nebula to ~3′ x 1’ in size. They fade gently into the darkness.

16″ at 228x + UHC filter: The three patches strung out along the superbubble’s southwest periphery respond well to the filter and become far more interesting. BSDL 2005 appears the faintest of the three, a pale round fog, ~45″ in diameter whose edges also simply melt away.

16″ at 228x + UHC filter: BSDL 2048 is revealed as a faint and misty roundish patch, 1′ in diameter and whose edges fade away with no discernible boundaries.

16″ at 228x + UHC filter: N206B (BSDL 2120) is the largest of the three patches and it appears as a fairly bright oval, 1.2′ x 25″ in size and elongated E-W, of foggy mist with very irregular edges that fade rapidly into the surrounding sky.

In all this swirling nebulosity, Wolf-Rayet Brey 40a has blown a bubble around itself, but in the telescope there is very little to see of the bubble. Credit: Y. Naze, G. Rauw, J. Manfroid, J. Vreux (Univ. Liege), Y. Chu (Univ. Illinois), ESO

16″ at 228x + UHC filter: There isn’t a lot to see of this Wolf-Rayet bubble; the visible fragment of its ring appears as an isolated, faint and ethereal mistiness with no defined edges on the southern side. It has a slight bubble-curve, very fragile-looking, and on the western side of the mistiness there is a short, dagger-thin little streak of slightly brighter brightness. Ethereal as the fragment of the bubble appears, Wolf-Rayet Brey 40a, makes up for it with its lovely 13.4 mag spark lying to the north of the visible fragment.