13-14 June 2021, 23:40 – 00:50 (BST)
Seeing: Average
Transparency: Poor
Conditions: A mild night with a light breeze. Very slight layer of condensation on the telescope tube after an hour.
All of tonight’s observations were carried out at 92x with the 13mm Ethos.
Nova Herculis 2021 (aka V1674 Her)
I was eager to see if the nova had got any brighter in the last 24 hours, but instead I found it had faded considerably by a good two magnitudes. (It was at a similar brightness to the nearby 8.5m field star HD 175919.) I didn’t notice any colour to the nova last night, but tonight it had a slight orange hue. I’ll be interested to read the explanation for this rapidly evolving nova’s behaviour once the analysis is completed, but in the meantime see:
Obviously, I’m glad I made the effort to see this nova last night rather than leave it for a day. It’s quite something to see a star change its appearance so dramatically in such a short span of time.
As well as V1674 Her, I also revisited a few other targets from last night. As expected, 61 Cygni looked lovely in the Ethos: a pair of pale orange headlights suspended in a sea of stars.
Open clusters NGC 6755 and NGC 6756 just about fit in the same fov at 92x, but I need a darker sky to really do them justice at this magnification.
But NGC 6709 did look better tonight. The Ethos gave the cluster more room to “breathe” and the v-shape formed by the brightest stars was more prominent.
NGC 6738, open cluster, Aquila
Plotted in SA 2000. Large, sparse cluster with a meandering line of stars running through the centre. Not impressive; I can see why it was left out of the PSA. Some sources don’t even recognise it as a real cluster.
NGC 6940, open cluster, Vulpecula
A long overdue return visit to this underrated cluster (its status isn’t helped by its proximity to the Veil Nebula.) Large, rich cluster of uniformly bright stars – fits nicely in the Ethos fov. A prominent red star (VG (or FG?) Vulpeculae) near the centre and a bright, close double on the western side of the cluster.
NGC 6826, “Blinking Planetary”, Cygnus
In same field as 16 Cygni in the Ethos; it’s hard to stop your eye constantly flicking from one to the other. Pale blue-green disc with a bright central star.
I rounded off the session with a look at the famous black hole Cygnus X-1, or to be more precise, its visible-light companion HDE 226868. It’s not that hard to find if you’ve got a decent map (I used chart 119 from my old copy of Uranometria). It’s the southernmost of a pair of 9th magnitude stars in a rich star-field near Eta Cygni. Like Nova Herculis 2021, this is a view to savour while you contemplate its astrophysical significance. I may not be able to see the black hole, but more I stared at that little patch of sky, the more I felt like it was staring into me.
Also, I wasn’t aware of this at the time, but Cygnus X-1 is right next to the much-photographed Tulip Nebula (Sh2-101).
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