Planetary Nebulae in Cygnus

13 – 14 September 2020, 22:30 – 01:30

Conditions: Humid, hazy, no wind. Heavy condensation from about 23:15 onwards, particularly on the star atlas.

Seeing: Average
Transparency: Poor

Experience has taught me there’s no point trying for faint stuff like galaxies when the sky is like this, so I devoted the session to planetary nebulae … at least until Mars rose into view. But before that I warmed up with a quick look at Albireo at 133x. Not much I can add to previous superlatives, other than to say that the 9x50 finder does split this double, although you can’t really make out the colours of the two stars.


NGC 6884, planetary nebula, Cygnus
133x and 171x. Tiny blue-grey disc, almost stellar. Only really stood out with averted vision.

NGC 6826, “The Blinking Planetary”, Cygnus
171x. Slightly oval, bright green-grey disc. Seemed slightly brighter on eastern side. Central star showing clearly.

NGC 7008, “Foetus Nebula”, planetary nebula, Cygnus
171x. This one’s been on my target list for a while, but it was almost directly overhead when I looked for it, which made getting the scope on it somewhat tricky. Large (for a PN) kidney bean-shaped nebula associated with a pair of bright stars. Quite a distinctive shape compared to all the various “discs and doughnuts” I’m used to seeing when I look at planetary nebulae. Use of averted vision revealed three bright spots in the larger portion of the nebula. I’m not sure if one of these was the illuminating star as it’s hard to tell where the centre is. The nebula appeared much brighter when the OIII filter was added; in particular the larger lobe was enhanced to the point where it overwhelmed the aforementioned bright spots. There also appeared to be two dark lanes cutting into the nebula at right angles, giving it a segmented appearance. An unusual object worthy of its nickname.

NGC 7048, planetary nebula, Cygnus
171x + OIII filter. Amorphous patch of light, adjacent to a 10th magnitude star. (Not a small nebula, but needs the higher magnification to separate it from the star.) The shape becomes better defined with averted vision: oval with a possible lobed structure.

NGC 7027, planetary nebula, Cygnus
171x + OIII filter. Small, very bright nebula. Shape-wise, it seemed slightly “squared off”, with two bright components of unequal size separated by a narrow dark lane (just visible with averted vision). One very bright spot on the western lobe – not sure if this was the illuminating star (offset from the centre) or just a prominent condensation. There also appeared to be a hazy outer halo surrounding the nebula, but this may have been caused by condensation. The nebula appeared much the same without the filter, but boosting the magnification to 428x with the 2.5x Powermate emphasised the boxy shape and the clumpy structure – particularly in the larger lobe. This object really does benefit from as much magnification that you can reasonably throw at it.

While at 428x I couldn’t pass up the opportunity to revisit an old favourite in Andromeda:

NGC 7662, “Blue Snowball”, planetary nebula, Andromeda
7mm DeLite + 2.5x Powermate. Impressively large at 428x! Still bright at this magnification, but the colour was more subdued – a pale greenish-blue. Darker centre with averted vision; no sign of the central star. Faint star due east. The nebula seemed slightly brighter on the eastern side, with a possible faint halo extending NE-SW, though again, this may have been a side effect of the condensation.


The rest of the session (00:15 – 01:30) was devoted to observing and imaging this autumn’s star attraction, Mars. Even under favourable conditions it’s a challenging planet to view, but I’m finding that with practice I’m seeing a little more detail each time out. As noted before, the Baader Contrast Booster filter really helps with this. The bright South Polar Cap is still the most striking feature, despite its diminishing size. The dichotomy between the darker southern and lighter northern hemispheres was also fairly easy to see, and eventually I was able to make out an isolated dark spot – Solis Lacus – near the centre of the disc (as often happens in astronomical viewing, it was so obvious once I’d noticed it that I wondered why I hadn’t seen it straight away). This is the first feature on Mars, other than the polar caps and Syrtis Major, that I’ve been able to positively identify. In fleeting moments of good seeing I glimpsed subtle colour variations across the surface, including a bluish haze on the northern limb. As yet I’m not seeing anything at 428x that I haven’t seen at 171x; still waiting for that elusive window of perfect seeing!

Nature note:
Plenty of frogs on the move. I have to be very careful where I’m treading.