Hello, everyone.
The Sun was setting late last Monday night - at 10 minutes to 10 pm.
1. But I did manage to find Arcturus a full 22 minutes before sunset through my William Optics 70 mm F/6 small apo at 11X. What a thrill!
It was some years ago when an acquaintance of mine challenged me to do such a thing - to observe stars before sunset.
Therefore my sky was very clear on this Monday night.
1. I could see the golden orange hue of Alpha Bootis in the main William Optics 158 mm F/7 apochromatic refractor at 40X straight away.
2. Then, of course, I was very keen to split Izar before sunset too. But I couldn't quite make it this time. Using my WO 70 mm F/6, Izar appeared at 21.51. That's just one minute after sunset. Consequently the main refractor successfully split Epsilon Bootis at 112X effortlessly easily. It then seemed to take a very long time before I could see Izar with my own eyes. Exactly 1 hour passed and then there he was about 10 degrees from Arcturus.
I had decided to wait for Izar to appear before I set out to tackle some more doubles in Corona Borealis.
3. I re-observed Zeta Crb, STF 1964, STF 1973 and PRT 5. The reason for that was to have another go at HJ 572 which is very close by to PRT 5. However there were only some very short moments when I could see the B component of HJ 572. I am now thinking that the magnitude of B is quite a bit dimmer than Stelle Doppie is stating. Magnitudes are supposed to be: A = 9.2. B = 11.7. Sep = 21.6". PA = 275 degrees. B ought to be directly west of A. It was only by using averted vision could I see B for very short second intervals. Even then the star would disappear immediately. My Guide 9.1 DVD says B is of magnitude 13.3. If this is correct; then it's no wonder I'm not seeing the star directly. Therefore I am considering HJ 572 as a dud.
The rest of these 3 doubles are first timers for me.
The figures are from
www.stelledoppie.it
1. STF 2044 is a true binary. Magnitudes: A = 8.4. B = 8.8. Sep = 8.2". PA = 341 degrees. I don't think A is a K0 class star as Stelle Doppie says. I did study it for quite a while, A appeared white to me. But B was more orange okay. I did split this double at 40X and 112X.
2. KU 53 is a true binary, Magnitudes: A = 10.4. B = 11.1. Sep = 5.3". PA = 49 degrees. I was pleased to split it at 112X. The faint 2 stars sitting side by side like 2 eyes. Both were white. KU stands for Karl Friedrich Kustner (1856 - 1936).
3. STF 2004 may be an uncertain binary. Magnitudes: A = 9.5. B = 10.3. Sep = 1.8". PA = 278 degrees. Quite a complex area of this part of Corona Borealis as there are so many faint stars. I had to tread carefully to find this little treasure. The double is south of Iota Crb. I achieved a delightful tight split at 112X. It also looked super at 140X. I was so relieved to find it. Patience is definitely required to locate STF 2004.
As the clocks chimed at midnight, it was time to end this very short session.
Clear skies from Aubrey.
