Good evening, all.
As many of you know I own a William Optics 158 mm f/7 apochromatic refractor supported by a Berlebach Planet alt-az mount and a William Optics 70 mm f/6 small apochromatic refractor attached with mirror diagonals fitted at all times on both scopes. These were my observations on Friday 3rd January 2020. They are all in Cassiopeia. No less than 5 doubles, I triple and, believe it or not, 1 sextuplet star system. The first 3 systems are very close to Beta Cassiopeiae (Caph). So close, in fact, it is relatively easy to fit all 3 and Caph in the same 2 degrees field of view (fov) at 40X.
All my figures are from
www.stelledoppie.it
1. ARY 7 is an optical double with magnitudes 7.8 and 8.3. Sep = 124.2". PA = 4 degrees. You could drive a bus through the huge gap of course. Easily split at 40X. Both stars are white. ARY stands for Robert Argyle.
.
2. ARY 8 is amazingly a true triple star with magnitudes 8.1, 8.6 and 8.3. Sep's = 39.1" and 104.3. The PA's are 100 and 43 degrees. Very attractively split at 40X. All 3 stars have slightly blue tints.
3. ARY 9 is an optical double with magnitudes 7.1 and 8.6. Sep = 138.7". Which is massive, I know. PA = 83 degrees. The colours are far more interesting: blue and yellow.
These next 2 doubles are very close to Caph also, and they are both utterly wonderful i.e, good and tight.
4. Stf (Struve) 3057 might not be a true double, but it is good and tight at 112X. The magnitudes are 6.7 and 9.3. Sep = 3.9". PA = 298 degrees. I also used 140X and 167X. Both stars are white
5. Stf 3062 is a true binary with magnitudes 6.4 and 7.3. The separation = 1.5". PA = 5 degrees. Both stars are white. I needed 140X to split it. But I have to say I could fit in both doubles at 167X. They are less than 14 arc minutes apart.
6. Sigma Cassiopeiae is another stunner. It's possible it may not be a true binary. The magnitudes are 5 and 7.2. Sep = 3.1". PA = 326 degrees. Nicely split at 112X. Both stars are white. It was my 1st time to observe it.
7. And so to the sextuplet ENG 88. This is truly a WOW spectacle! I was totally amazed I could see all 6 components at a lowly 40X. But of course I had to push the magnifications up and up. The magnitudes are 7.2, 10.6, 10.8, 9.8, 10.9 and 9. The separations are 170.6", 146.7", 228.9", 167.4" and 281". The PA's are 215, 165, 198, 147 and 197 degrees. The highest power I used was 167X. The brightest star is yellow and its designation is TYC 4008 18. I realise the Trapezium in the Orion's Nebula is very famous. But do consider have a go at ENG 88. I promise you will not be disappointed at whatever power you use! You will find near Tau Cassiopeiae.
8. Finally I did check out NGC 7789 the open star cluster which has the nickname Caroline's Rose. At this stage seeing conditions got worse. So I won't give too much detail. I used 167X on it. But owners of larger telescopes would fare much better than mine. I could see approximately 20 stars. Its brightest star is M class and is red and has a magnitude of 8.4. North of it was a zigzag set of stars which are very dim. But I did see them alright. It would be exceedingly good to observe it at the Sugarloaf car park. Imagers would have a great time with NGC 7789. Many have done so over the decades.
Thank you for reading.
Comments are always welcome.
Clear skies,
Aubrey.
