A red supergiant and a false Saturn in Cepheus

[Martin Meredith]

With the moon up and about I continued to focus on open clusters and managed to observe a further 6 Berkeley clusters (2 in Lacerta and 4 in Cepheus) this evening until my mount battery gave up for the night.

One of these clusters in particular I found fascinating for reasons other than the cluster itself. This is Berkeley 95 in Cepheus. For once, the 3' cluster is easily spotted and quite well resolved in the middle of the shot with what seems to be a characteristic signature (no doubt illusory) of some Berkeleys, namely a pair of near-circular arcs of stars --a good-looking cluster as these faint ones go.

However, the attention is drawn to the bright red star above the cluster. This is the mag 8.65 red supergiant variable V674 Cep, type M3Iab, with a colour index of 3.88 (GAIA blue-red index is even higher, at 4.5). Its mag 14.2 yellow 'companion' (I'm not sure if it is a real companion) is just about visible peeping out at around 11 o'clock. This must be amongst the brightest/reddest stars visible and I wonder how it would appear in binoculars or a small scope.

But what I really like about this field is the 'false saturn' that is evident at 8 o'clock. This triplet is aligned in such a way that the two fainter 'wings' are just offset to give the tilted Saturn-like impression. I see a lot of star fields doing EEVA and this is the first time I've come across a jewel like this. Again, something to look out for in a medium-sized scope perhaps?

 

 

cheers

Martin

 

Edited February 5, 2020 by Martin Meredith

[Mike JW]

Hi Martin, the Saturn like star is TYC 3995-30-1. I was hoping it might be a double/multiple as I very much enjoy doubles. However it is simply a chance alignment. I shall add it into my double star list for Cepheus as a fun target.

Mike

Edited February 6, 2020 by Mike JW

[Martin Meredith]

Hi Mike

Thanks for that ID. It was too much to hope for a physical grouping. I think the same goes for V674 Cep (I couldn't spot it in the WDS list).

Martin

 

[Mike JW]

The area around Berk 95 is very lacking for doubles. I have noted V674, it will be interesting to see if I can detect colour visually with the 15 although its mag 10/11 status might make it too faint for clear cut colour detection. I might take a look tonight despite the moon.

Mike

[Mike JW]

Hi Martin, Tonight I pointed the Dob at V674 - definite orange colour. I also located "saturn", also showed a hint of orange colour but I could not see its "rings" - no idea of the mag of these stars but I am guessing mag 13/14. I should try again on a moonless night. As to Berk 95 - about 4 stars!!!!! Hence I have enjoyed your EAA shots of the Berkeley Clusters. Mike

[Martin Meredith]

Nice work. I checked on Simbad and the Gaia G mags are 13.5 and 13.6, so good guess! 'Saturn' itself has Gmag 10.5. Tonight is predicted to be clear and in spite of the moon I'll see if I observe some of the remaining Bs in CAS...

Martin

[Mike JW]

Have fun. Cloudy here for me but working on a lunar sketch. Mike

[Howie_Oz]

Thanks Martin, wonderful find! Also thanks for adding all the coords etc to your image. ;)

 

[Martin Meredith]

Thanks Howie. Fortunately, the adding of coords etc is all automatic (if the object is in the database).

Martin

[RobertI]

On 05/02/2020 at 20:46, Martin Meredith said:

But what I really like about this field is the 'false saturn' that is evident at 8 o'clock. This triplet is aligned in such a way that the two fainter 'wings' are just offset to give the tilted Saturn-like impression.

Another interesting EAA object to add to your book