Observations - 30th March + 1 & 2 April 2021

Hello, everyone. 

I'm finally finding the time to report on all I have been observing from my back garden with my William Optics 158 mm F/7 apochromatic refractor on the nights 30th March, 1st and 2nd April. 

1. I started with Alpha Aurigae (Capella). HJ 2256 is an optical double. Magnitudes: A = +0.1. F = 10.2. Sep = 107.5". PA = 135 degrees. As B, C, D and E are far too faint for my scope, great joy can still be had when F is spotted at a mere 40X. The primary, which is the 6th brightest star in the entire sky (4th brightest in Irish skies) and has that famous yellow colour all right - especially when viewed at 112X. HJ stands for John Herschel who was William Herschel's son. 

2. Theta Aurigae (Mahasim) is a quadruple star otherwise known as STT 545. A and B are a true binary. But C and D are optical. Magnitudes: A = 2.6. B = 7.2. C = 11.1. D = 10.1. Sep's from A = 4.1", 56.4" and 139.2". PA's = 304, 300 and 349 degrees. I have to admit this is my very first time to observe the C component. All 4 white stars visible at 112X and 140X. What joy!. A and B are simply stunning to my eye. STT stands to Otto Struve who was Friedrich Struve's son. 

3. The carbon star UU Aurigae has a double star designation: BLL 17. Stelle Doppie states BLL 17 is an uncertain double. Magnitudes: A = 5.1 to 10 (variable star). B = 11.8. Sep = 116.9". PA = 223 degrees. A which is bright has such a rich and beautiful orange colour. B is white. As the B star is only visible from 112X, there is already plenty of black space in between. 140X and 167X make B more easily seen. One individual on Cloudy Nights has informed that BLL stands for a man who is a Dubliner. He is Robert Stawell Ball. who lived from 1840 to 1913. He wrote a book "A Story of the Heavens" and I have a hardback copy of it in my attic. UU Aurigae is the 2nd carbon star I have observed in the Charioteer. And my 101st carbon star. 

Now that I have reached UU Aur, I shall now continue with the many double star systems which I observed  close to the carbon star. 

4. STF (Struve) 940 is 9 arc minutes from UU Aur. It is a true binary. Magnitudes: A = 8.8. B = 10.3. Sep = 10.3". PA = 295 degrees. The 2 white stars are split at 40X. But it was a better sight at 112X and still in the same fov as UU Aur. 

5. AG 116 is an uncertain double 15 arc minutes from UU Aur. Magnitudes: A = 9.8. B = 10.6. Sep = 2.2". PA = 31 degrees. It was a challenging double. I was delighted to get the split at 167X with the tiniest black gap between the 2 white stars. AG stands for Astronomische Gesellschaft. At that magnification UU Aur was not in the same fov. 

6. STF 928 is an uncertain double. Magnitudes: A = 7.9. B = 8.6. Sep = 3.4". PA = 131 degrees. A has an F class yellow-white hue. B is blue-white. What a beautiful sight at 112X and 140X! Both stars were sitting side by side with a tight black gap between them. 140X proved breathtakingly serene too. I have run out of superlatives. It was most definitely the greatest find of the night for me.!

7. BU 194 is an uncertain double. Magnitudes: A = 8.6. B = 8.9. Sep = 1.6". PA = 278 degrees. A is yellow (G class). B is white. And again what a beautiful split I had at 112X and 140X. The 2 stars have almost the same magnitude. And that very much made this double all the more enhancing.  A real splendid winner! And almost as good as STF 928.

8. STT 147 is a triple star very close by. A and B are a true binary. But C is an uncertain companion. Magnitudes: A = 6.8. B = 8.7. C = 9.9. Sep's from A = 42.7" and 44.5". PA's = 74 and 119 degrees. A is K class orange. B = F class yellow-white. C is white. Effortlessly split at 40X of course. But the colours looked very good at 112X. When I saw the system first, I likened it to a planet with 2 moons. 

9. STF 929 is an uncertain double. Magnitudes: A = 7.4. B = 8.4. Sep = 6.5". PA = 24 degrees. A is G class yellow. B is white. Sweet split at 40X. 112X was very good to see the yellow colour of A. 

10. AG 117 is a true binary. Magnitude's: A = 9.6. B = 10. Sep = 8.8". PA = 118 degrees. These 2 white stars were easily split at 40X and 112X. It was such a delightful sight for yours truly. 

 Each of these doubles and 1 triple are within 2 degrees south of UU Aurigae. It was so thrilling to succeed in splitting each one - 7 in all!

11. I have one last double which was further north of UU Aur. STT 154 is a short distance south of the open star cluster NGC 2281. STT 154 is an optical double. Magnitudes: A = 7.1. B = 9.7. Sep = 23.6". PA = 84 degrees. Easily split at 40X. But I have to say the colours were very unusual. A was orange to my eye - even though its spectral class is M4. B seemed to have an almond brown hue. What an excellent sight at 112X, 140X and 167X too. 

12. I observed the 15 arc minute open star cluster NGC 2281 for the very first time from magnifications 40X up to 167X. Straight away I was delighted to have noticed 4 stars which were shaped like a diamond pointing downwards to my north western horizon. Then after some time, I could easily make the big fish - which was extremely enjoyable to behold. I also observed the fish's tail with no problem. I counted 3 orange stars around the open star cluster - very nice indeed, and one bright orange star of +8.9 magnitude near the centre of NGC 2281. It is easy to see why I am now a fan of NGC 2281.

13. I finished up last Wednesday night including with an observation of Polaris. Magnitudes: A = 2. B = 9.1. Sep = 18.4". PA = 236 degrees. Split at 40X. A is yellow-white. B is white. What I consider fun is noting where the B component is as the months go by. At 11 pm on 30th March it is located in the 5 o'clock position. In a month's time it will eventually be in the 6 o'clock position. All this is happening because the Earth is turning on its axis. 

Then on Thursday night 1st April, Valerie joined me in observing almost each of the above except Capella and Polaris. 

14. Finally, on Friday night 2nd April, Valerie was with me again to observe a very special carbon star which is also a double star!!   An imager called Steve Smith from Colorado issued me with a challenge to find the carbon star UV Auriga. There was due. So I kept my observing session for no more than one hour. The Irish weather folk had issued a warning that this was going to happen come what may. They were 100% right. And talk about looking for a needle in a haystack, UV Aurigae is just plain tough to find. I started my star hop from Beta Tauri (Elnath) and headed up to 18, 19 and 16 Aurigae which were very easy to find in my WO 70 mm F/6 small apo.  As you might imagine looking for a magnitude +8 star when there were so many other magnitude +8 stars nearby was showing me how difficult it was going to be to bump into UV Aur. But I had my Guide 9.1 DVD map with me okay. And so off I went seeking out an orange carbon star. It has other designations of course. BD+32 957, HD 34842, TYC 2394-373-1 and SAO 57941 to name four others. The spectral class is C8. It is a variable star also which has a magnitude range from 7.3 down to 11.1. In the end, I did figure out which star was which, and the orange colour was evident at a mere 40X. It was when I increased to 112X I could see that an 11.0 magnitude companion was visible at a position angle of 5 degrees. The separation is 3.5 arc seconds.  And at 112X the orange hue of UV Aurigae became more pronounced. I finished up at 225X using my Nagler 5mm eyepiece to see both stars. What a true beautiful pair they both are!  It was then at 225X when I could get glimpses of the blue colour of the secondary now and again. When UV Aur becomes a double star we are permitted to use the double star designation HU 614 as Steve and Stelle Doppie had pointed out. HU stands for the American astronomer William Hussey who lived from 1862 to 1926. I can only imagine how he felt when he discovered HU 614 in 1901.  UV Aurigae is my 3rd observed carbon star in Auriga. Plus it is my 102nd overall. I recommend it to everyone here! 

That's it from me, folks. 

I do very much thank you for those who have read this latest report. 

I wish you all a very joyful Easter!

The Lord Jesus is risen.  

Clear skies from Aubrey. 

 

I hadn't known Robert Ball was listed in the double star catalogues Aubrey.

Here is probably the most official source -

www.astro.gsu.edu/wds/Webtextfiles/wdsnewref.txt

and indeed BLL does stand for the well-known Birr and Dunsink astronomer.

Great report again.

Clear skies,
Finbarr.

Hello, Finbarr. 

I was greatly surprised too when I received the news that Robert Ball had this wide double BLL 17. 

And the man who told me is from San Francisco.

But I do thank you so much for checking the double out on your vast link. 

Very best regards from Aubrey.   

Hello Aubrey,

Your detail report was a joy to read. Your descriptions of STF 928 and NGC 2381 were fantastic, and I was delighted to read that you and Valerie observed so many nice stars over Easter. 

Thanks for letting us know about the Irish contribution too. For the size of our country it certainly seems to punch well above its weight when it comes to astronomy. 

Clear skies, 

​​​​Darren.