I travelled down out of Dublin in Ireland to the Sugarloaf car park County Wicklow on Sunday night 19th July in my car with my William Optics 158 mm F/7 apochromatic refractor and its Berlebach Planet alt-az mount plus all the equipment in the boot.
The drive only lasts 30 minutes; and as I reach my destination at 9.30 pm local time, there are clear skies all around. I am in a Bortle 5 zone.
I started observing at 10.15 pm and did not finish until 1 am on Monday morning.
At 2 am I was trying to get to sleep. It turned out to be a thrilling night of observing.
There was quite a good bunch of us in the car park.
So after all that introduction, I spent some time in Corona Borealis.
I hadn't visited this constellation since 24th June.
As my heading states, I had the business of observing 4 doubles and 1 triple - none of which I had observed before.
All figures are from www.stelledoppie.it
1. Ho 399 turned out to be the only true binary of the night. Magnitudes: A = 7.7. B = 10.5. Sep = 3.7". PA = 117 degrees. It can be a difficult double to split if the sky isn't completely clear. But this time, under a less light polluted sky, I had no problem seeing the B star at 112X. It did look better at 140X and 167X. Ho stands for George Washington Hough (1836 to 1909). Both stars are white. It's very close to Iota Coronae Borealis.
2. STT 304 may be an uncertain double, but what a fine sight it truly is. Magnitudes: A = 6.8. B = 10.6. Sep = 10.4". PA = 173 degrees. 40X is enough to see B good and close. 112X makes this double clearer. STT stands for Otto Struve (1897-1963). It's north of Lambda Crb.
3. Which brings me to Lambda Crb (12 Crb). Rich from the UK discussed this optical double on 10th June. It has taken me all time time to finally observe it. Magnitudes: A = 5.5. B = 11.4. Sep = 90.6". PA = 68 degrees. What surprised me here was I could see B at the lowly power of 40X. As the gap was sufficiently wide, I decided there was no need to go higher. So a big thank you to Rich for pointing it out to the rest of us. My only source for it is Stelle Doppie, and I'm glad I did not miss out on it. A is F2 yellow-white. B is white. Special thanks to you once again, Rich.
4. H 5 75 is an optical double. Magnitudes: A = 7.9. B = 11.5. Sep = 57.1". PA = 113 degrees. Again there is no need to go higher than 40X. A is F2 yellow-white. B is white. It's south east of Epsilon Crb.
5. Wasn't it Mauigazer who drew our attention to SHJ 223? Indeed it was. Well it is also called Upsilon Crb and it is an optical triple star. Magnitudes: A = 5.8. C = 10.4. D = 10.4. Sep's = 87.5" and 123.3". PA's from A = 21 and 50 degrees respectively. All 3 stars split at 40X of course. But I recognised the need to go quite a bit higher. The spectral classes are: A3, A and M8. Therefore A and B are both white. However C is red! I could make its true colour at magnifications 112X, 140X and 167X. What a super sight it is to see a fine red star in any of these eyepieces. Thank you, Steve from Hawaii.
So that's it! It has been a long 3 and a half weeks since I did any observing.
It was truly worth it.
I had other celestial objects including Comet Neowise on the same night.
I wish you all clear skies from your friend Aubrey.