Hello everyone.
As you all know, my main scope is a William Optics 158 mm f/7 apochromatic refractor.
Its guidescope is another apochromatic refractor which is a William Optics 70 mm f/6 with mirror diagonals fitted to both scopes at all times.
They are attached to a Berlebach Planet altazimuth mount.
Some time ago a friend on Cloudy Nights recommended that I should do an observation of 35 Cassiopeiae.
While I was checking the position of this optical binary, I also checked out some more doubles which are close by.
As ever, I printed off a map from my Guide 9.1 DVD.
I observed another 5 doubles on the same night (Thursday 17th October) and I have included their magnitudes, separations and position angles which all come from the reputable website
www.stelledoppie.it
1. 35 Cassiopeiae: Magnitudes: 6.3 & 8.6. Sep: 57.4". PA: 342 degrees. The primary is almost completely white with the slightest tint of blue at higher magnifications. Its spectral Class is A2. At 40X I had no problems seeing a good split between A and B.
But you will want to know what was the colour of the secondary I saw. So I steadily increased my magnifications from 112X to 140X, and lastly 167X. Sissy Haas records in her Double Star book for Small Telescopes that the star is rose red. I thought it is more tangerine. But my wife thinks it is a rusty colour. As yet I have not been able to discover the spectral class of 35 Cassiopeiae B. Perhaps some of you could find out for me. I will be delighted to hear from you. Please do clear up this mystery. Either way, I can safely say that 35 Cass is an absolute gem! The secondary has a most unusual hue.
2. 44' east of 35 Cass is another optical double star and I had no problem splitting Stf 121 at 40X. Magnitudes: 9.5 & 10.2. Sep: 12". PA: 268 degrees. I did find its colours quite fascinating also. A is definitely orange. B is yellow. How rare is that? Therefore to appreciate those colours even more I used the same magnifications: 112X, 140X and 167X. Despite its dimness I found it very pleasurable.
3. Stf 109 probably is a true binary. It is 47' south of 35 Cass. Magnitudes: 9.9 & 10.5. Sep: 7.3". PA: 9 degrees. 40X gave an easy split. 112X was nice too. Both stars are white.
4. Sti 200 was designated by J. Stein. (Who's he?) Anyway it is another easy split at 40X. It might be a true binary almost 1' southwest from 35 Cass. Magnitudes: 10.4 & 11.1. Separation: 11.3". PA: 152 degrees. Extremely faint at low power. More pleasing at 112X. It is very near Stf 109. Some might call the pair a double - double. Although there is quite a gap between them.
5. HJ 1085 is a splendid true binary which is about 2 degrees east of 35 Cass. The primary is yellow - orange. The secondary is white. The magnitudes are almost identical: 9.5 & 9.6. Sep: 3.9". PA: 298 degrees. I required 112X to split it. I greatly admired it at 140X and 167X.
6. 12' northwest of HJ 1086 is a one of the faintest optical doubles I have ever observed. It's that guy J. Stein again. Sti 245 was not visible at 40X. But at 112X, 140X, 167X and 225X I had no problem seeing A and B split. Both stars are white. Magnitudes: 11.2 & 11.9. Sep: 12.7". PA: 81 degrees.
There are a few more doubles near 35 Cassiopeia I plan to observe some time soon.
I must share with you one last thing I noticed.
At the start of the evening, the constellation of Cassiopeia was shaped like a true "W".
But by 11 pm local time, it had become a vertically zigzag as the set of stars climbed higher in the north eastern sky.
Please feel free to comment.
Thank you for reading.
Clear skies from Aubrey.
  