Nebulae in Cepheus and Cassiopeia

20 – 21 September 2020, 21:45 – 01:00

Conditions: Chilly, breezy. Light condensation appearing as the temperature dropped.

Seeing: Good
Transparency: Poor

With Mars now larger than the magic 20-arcsecond threshold, deep-sky observing (and indeed deep-sky astrophotography) will be playing second fiddle to the red planet for the next couple of months. (The autumn constellations will be back next year; Mars won’t be this good again until 2030-something.) That said, the nights are getting longer, so I was able to get a couple of hours of observing before Mars took centre stage.

I started with a short wander around Cygnus at 133x, during which I stumbled across 27 Cyg – a close double in a dark nebula (B146). The transparency in this part of the sky was very poor (the Crescent Nebula was disappointing – even with the filter it was barely visible ), so I relocated to Cepheus.


NGC 7538, emission nebula, Cepheus

133x + OIII filter. Initial impression was of an amorphous patch of light, like a puff of smoke, surrounding a pair of 11th magnitude stars. Averted vision showed some detail in the form of mottling, including what looked like a dark lane or rift on the eastern side of the nebula. Not a showpiece object by any means, but not bad given the middling conditions. Switching up to 171x plus the Ultrablock filter gave much the same view, but larger and fainter – although the two central stars were easier to see. The nebula was just barely visible without the filters.

IC 1470, emission nebula, Cepheus

133x + OIII filter. I never know quite what to expect when tracking down obscure IC-designated nebulae. Sometimes they’re surprisingly bright; other times they’re all but invisible. However this object was fairly easy to spot as a quite small, fuzzy round patch of light. The core appeared stellar with averted vision. Increasing the magnification to 171x (no filter) showed a star embedded in a wide, fan-shaped nebula, a bit like a comet. (It reminded me of Hubble’s Variable Nebula, NGC 2261.) The Ultrablock filter offered a little improvement: the central star became harder to see, while the nebula itself seemed more triangular and harder-edged.

A quick look at the eye-catching clusters NGC 7510 and Mrk 50 (see last year's notes on these) and then onto another nebula.

NGC 7635, Bubble Nebula (Caldwell 11), Cassiopeia

171x + Ultrablock gave the best view, though it wasn’t nearly as good as my previous look at this object (perhaps the Ethos plus the OIII filter would be a better combination). Bright star associated with a nebula of indistinct shape; with averted vision it looked a little bit like one half of a Yin-Yang symbol.

NGC 40, “Bow-Tie Nebula” (Caldwell 2), planetary nebula, Cepheus

171x + Ultrablock filter. While reading up on this nebula (after my observation on 16 September), I found some reports claiming it responds better to narrowband filters than OIII. Now I’ve tried both I do think the Ultrablock filter gives a slightly better view than the OIII, but this nebula is bright enough that it doesn’t really need it. The two arcs were a little easier to see (with averted vision), but of course it helps when you already know where they are.


Mars: The combination of the 9mm Nagler and the 2.5x Powermate (giving a magnification of 333x) seemed to hit the sweet spot tonight, giving me my finest view yet. The SPC was a brilliant little oval and the Sinus Meridiani (home of the Mars Opportunity rover) and Sinus Sabaeus regions were showing particularly well. I could also see a blue haze over the north polar region and brighter patches along the morning limb. I swapped the eyepiece for a camera and captured some videos, resulting in the image below:

Planetary Nebulae in Cygnus (again) and Cepheus

15 – 16 September 2020, 21:30 – 00:30

Conditions: Much the same as the previous night, but warmer(!) with heavier condensation.

Seeing: Average
Transparency: Poor

I warmed up with a look at globular clusters M15 and M2 with the 7mm DeLite (171x). As noted before, M15 has a significantly condensed core compared to the looser M2, but overall the brightest stars in M15 were brighter than those in M2, making it (M15) a little easier to resolve. M2 had one prominent star (noted on previous occasions) residing in a dark void just east of the core.

Then it was back to Cygnus to catch up on a few planetary nebulae I missed last night.


NGC 7026, planetary nebula, Cygnus
171x. Located just north of 63 Cyg (and easy to overlook on a star chart – which is why I missed it last night despite being in that area) – almost in the same field at 171x. The nebula itself appeared as a little ellipse of green-grey light immediately west of a bright star. Possible lobed structure with averted vision, but even at 171x it was so small it was hard to be sure.


I then spent an inordinate amount of time looking for PK 80-6.1, the so-called “Egg Nebula”. (I should know better than to go after PK-designated planetaries, but I figured that an object worthy of a nickname is probably worth tracking down … probably.) Eventually I did stumble upon a star-like point surrounded by a faint haze – looking more like a tiny galaxy than a PN. With averted vision it seemed doubled. By the time I’d put the OIII filter in, it had left the field and I couldn’t find it again (or if I did, I didn’t notice it). Not sure about this one.


NGC 40, “Bow-Tie Nebula” (Caldwell 2), planetary nebula, Cepheus
171x. Surprisingly faint in OIII, but when I removed the filter I could see a bright central star embedded in a round shell of nebulosity. Averted vision suggested an asymmetry in the form of brighter arcs in the SE and NW sides of the shell. Faint star due west of the nebula.

I failed to spot NGC 7139 in central Cepheus, but I had better luck with the next target:

NGC 7354, planetary nebula, Cepheus
171x. Faint oval disc; brighter with averted vision. A little brighter still with the addition of the OIII filter, plus a suggestion of “clumpiness” with averted vision. Plotted in SA 2000 but not the PSA.


I spent the remainder of the session looking at Mars before a combination of condensation and tiredness forced me back inside. It looked much the same as it had the previous night, although Solis Lacus was rotated a little closer to the limb.