4 stubborn doubles in Cassiopeia

4 weeks 2 days ago - 4 weeks 1 day ago #107876 by flt158
4 stubborn doubles in Cassiopeia was created by flt158
Hello, everyone once again.

This time I have 4 difficult doubles which I successfully split on Saturday 19th October 2019. There are a few extra doubles and triples which are far easier.

Sunset has occurred and my William Optics 158 mm f/7 apochromatic refractor is in its correct position.

1. Before a single star appeared, I had found Arcturus shining quite low in the northwestern sky. Already its golden orange hue was good and strong at both 11X in my 70 mm apo guidescope and 40X in the main apo.

2. Straight up by about 8 degrees, I easily could see Izar in the 70 mm. Beautifully split at a mere 112X. Magnitudes: 2.8 & 4.8. Sep: 2.8". PA: 347 degrees. Yellow - orange and slight blue are the colours. It is also excellent at 140X, 167X and 225X. No wonder it is called Pulcherrima and it is a true binary. which was discovered by F.G.W. Struve.

3. Time to zip up to Cassiopeia. Iota Cassiopeiae I have observed many many times in recent years. Easily split at 112X. Magnitudes: 4.6, 6.9 and 9.1. Sep: 2.6 & 6.7. PA's: 227 & 117 degrees. All 3 stars are white with a slightest hint of blue.

4. Up a bit there is a large open star cluster whose designation is Collinder 463. I refused to go over 40X and there are plenty of stars with different colours within its boundaries. Its magnitude is about 5 overall. Collinder star clusters were discovered by Per Collinder who was a Swedish astronomer.

5. Right on the southern border of Cr 463 there is an easy double star. HJ 1089 is an optical double. Magnitudes: 9.4 & 10.2. Sep: 26.2". PA: 89 degrees. Split at 40X. HJ stands for John Herschel.

6. But right next to HJ 1089 we have the first of my stubborn doubles. HJ 1090 is seriously faint. Magnitude: 11.1 & 11.3. Sep: 9.1". PA: 335 degrees. I did split it at 280X; and after that I discovered I could split at 225X, 167X and 140X. Of course at all those powers both doubles HJ 1089 and HJ 1090 are in the same fov.

7. HJ 2068 Is positioned in the western part of Cr. 463. Tough one it is too. Magnitudes: 11.3 & 12. Sep: 6.6". PA: 142 degrees. Because of the faintness of the secondary I required 225X to see both stars.

8. Psi Cassiopeiae is another wonderful triple. Magnitudes: 4.7, 9.2 and 10. Sep: 20.3" & 19.1". PA's: 128 & 131 degrees. The 2 faint stars have a separation of 2.9". I personally prefer Psi Cass to Iota Cass.

9. HU 1021 was by far the stubborn double star I observed on this Saturday night. It is actually a triple. Magnitudes: 8.9, 11.9 and 11.7. Sep's: 3.3 & 37.8. PA's: 304 & 198 degrees. The C component is easy to see at 112X. But to see that B star, I needed 225X and even then, it was not visible at all times. 280X and 320X were a little easier, but not by much. See what you think! Clearly that faint delta magnitude difference of 3  caused me enormous difficulty.

10. HU 1019 is another tough double. Magnitudes: 8.6 & 10.4. Sep: 1". PA: 200 degrees. I did successfully split it at 280X and 320X. The delta mag is not too bad.

11. Very nearby is a fainter but easier double. HJ 1061 has magnitudes 10.5 and 11.4. Sep: 13.1". PA: 103 degrees. Both stars split at 112X.

Needless to say getting to sleep last night was difficult after an amazing night observing 4 seriously tough doubles and everything else.

That's it from me.

All comments are welcome.

Clear skies from Aubrey.
The following user(s) said Thank You: michael_murphy, Fermidox, scfahy, Until_then-Goodnight!

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4 weeks 1 day ago #107877 by scfahy
Replied by scfahy on topic 4 stubborn doubles in Cassiopeia
Allways look forward to your observations.
The following user(s) said Thank You: flt158

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4 weeks 1 day ago #107878 by Until_then-Goodnight!
Replied by Until_then-Goodnight! on topic 4 stubborn doubles in Cassiopeia
Hi Aubrey,

Great report, and I very much liked reading the history behind some of stars - thank you!

Clear skies,

Darren.
The following user(s) said Thank You: flt158

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