Hello double star aficionados.
On Thursday night 23rd September 2021 I finally got a clear night after 4 full weeks of cloudy nights.
I could NOT wait to set up my Williams Optics 158mm F/7 apochromatic refractor on its Berlebach Planet altazimuth mount in the back garden. My Dublin sky was almost 100% clear from 8.45 to 10.30pm. Sunset had occurred at 19.20 local time. The temperature was a steady 11˚ Celsius. The 15 km/h winds were clearly keeping all dew away.
I live under Bortle 9 skies.
All these double and triple star systems are in Cassiopeia.
6 of them are totally new to yours truly.
Some of them are real gems!
And they are all relatively easy to locate by star hopping and are quite easy to separate very cleanly.
I never went above 140X at any time.
All figures are from
www.stelledoppie.ie
1. Having started with Schedar (Alpha Cassiopeiae), Achird (Eta Cassiopeiae) I headed to the super triple - or should I say - quadruple Iota Cassiopeiae (STF 262). A & B are a true binary. But both C & D are optical companions - even though C is so close. Magnitudes: A = 4.6. B = 6.9. C = 9.1. D = 8.5. Sep’s from A are: 3”, 6.7”, 210.9”. PA’s = 228˚, 117˚ & 60˚. It doesn’t seem to matter how many times I observe STF 262 it still looks most impressive at 112X. The 3 main stars, which are white to me do, in their arrangement, look so superb at a low magnification.
2. Not far away from Iota we have another magnificent triple star which is even more beautiful to me. It is Psi Cassiopeiae (H 5 83). The secondary B star is too faint to me. A & C are optical. But C & D are a true binary called STF 117. Magnitudes: A = 4.7. C = 9.2. D = 10. Sep’s from A are: 20.3” & 19.1”. PA’s = 128˚ & 131˚. STF 117's separation is 2.9”. Their PA is 253˚. All 3 stars are delightfully split at the low power of 112X. The K class primary is slightly orange. The two tiny companions are white and they are extremely close together at 112X. Psi Cassiopeiae is an excellent triple for everyone. I even prefer it to Iota Cas for some strange reason.
3. The rest of these doubles are first time observations. STF 48 is a real beauty! Magnitudes: A = 7.8. B = 8.1. Sep = 5.4”. PA = 333˚. It may be an uncertain double but it is an exquisite sight. A wafer thin split at 40X; and a stunning sight at 112X. I saw both stars as pure white.
4. STF 57 is a buried treasure right next to a bright 5.9 magnitude orange star called SAO 4229. If you set out to find this star you will discover STF 57 is seriously faint and in the same field of view. Magnitudes: A = 10.5. B = 10.9. Sep = 6.3”. PA = 199˚. I had no trouble splitting it at 112X. And I found it to be delicately beautiful at 140X also.
5. After all this excitement I didn’t find HJ 1989 particularly impressive. It’s more of your “normal” set up of a double star and it is an uncertain double. Magnitudes: A = 7. B = 11.5. Sep = 31.8”. PA = 52˚. The two stars appeared white to me. There was plenty of space between them at 112X. Anyway it’s ticked off the list.
6. HJ 1983 was much more pleasant even though it is an uncertain double. Magnitudes: A = 8.5. B = 10.1. Sep = 40.9”. PA = 305˚. Its primary is a nice K5 class orange star. But then I was soon to discover that the secondary is orange too. A nice surprise and a nice view at 40X & 112X.
7. 21 Cassiopeiae or H N 122 is a true binary. Magnitudes: A = 5.7. B = 10.6. Sep = 35.9”. PA = 161˚. Both stars were white at 112X.
8. Finally HJ 1997 is in the same field of view but it is an optical double. Magnitudes: A = 10.6. B = 10.7. Sep = 17.6”. PA = 47˚. I first got a slight glimpse at 40X and the 2 stars were cleanly separated. I went no further than 112X to greatly admire such a nice double.
Thank you for reading my latest report.
It seemed so long since I had a good session.
Comments are most welcome.
My personal favourites were: Iota & Psi Cassiopeiae, STF 48, STF 57, HJ 1983 and HJ 1997.
Maybe next week I will have another clear night.
Until then: Adios, Amigos!
Very best regards and clear skies from Aubrey.
