Observations - 7 & 8 August 2020

Hello, everyone.

I managed to take a break from the snooker to observe some nice celestial objects on both Friday 7th and Saturday 8th August 2020 with my William Optics 158 mm F/7 apochromatic refractor.
On Friday night the skies did not clear until 11 pm. The 3 weather websites I frequently use had said my Irish skies would be clear from 7 pm. As you might imagine, I was going to give up any hope of doing any observing when 11 pm occurred. However I ended up observing until 00.45 am local time.

1. Arcturus was first as per usual. It still is my favourite 1st magnitude star. Its golden - orange colour is always so admirable to behold. But has anyone asked themselves about the other star in the same field of view? It's about 19 arc minutes from Arcturus in a south easterly direction. Well, I have finally sought to check out its designation. It's CN Boo - which implies it is a variable star of sorts. Sadly though, it varies only by a minuscule amount: from maybe magnitude 5.8 to 6.1. It is a white A5 star. But it is a nice contrast to Arcturus. Otherwise it can also be called: TYC 1472 1427, SAO 100949 or HD 124953. Take your pick!

2. Izar ( Epsilon Bootis) is now straight up from Arcturus by about 10 degrees in the western sky. Friedrich Struve (1793 - 1864) considered this magnificent but uncertain double as "Pulcherrima" - which means most beautiful. I fully agree with Mr. Struve - although it was wider in his day. It certainly is a glorious sight. Magnitudes: A = 2.6. B = 4.8. Separation = 2.8". PA = 347 degrees. Spectral classes: K0 and A2. Excellent tight split at 112X. I subsequently observed it at 140X, 167X and 225X on Saturday night. It is also called STF 1877 by Struve. I see its colours as yellow-orange and slight dark blue.

3. A mere 1 degree north of Arcturus I reacquainted myself with STF 1825 which is a true binary. Magnitudes: A = 6.5. B = 8.4. Sep = 4.4". PA = 152 degrees. A delightful split at 112X was to be had.

4. I could observe M13 - the great globular star cluster in Hercules - but only for a minute or two as I had problems with cloud. But I was happy I could see it at all at 11X with my small 70 mm F/6 apo.

5. I could see Lyra overhead. So I observed Zeta Lyrae and saw both stars split at 11X. On Saturday night I returned to it and increased the magnifications up to 140X. Figuring out its colours is rather difficult. But this time I settled on white and yellow - white. Other scopes probably do differ on this uncertain double.

6. I could see the "O" of the Ring Nebula M57 at 112X. Its magnitude is 8.8.

7. Then on Saturday night I did get to the famous Double - double in Lyra. What a super sight it is at 112X. Both doubles clearly but tight splits at that power. Both doubles are true binaries.

8. Eta Lyrae (Aladfar) is an easy split at 40X. Magnitudes: A = 4.4. B = 8.6. Sep = 28.4". PA = 81 degrees. The colours I saw are white and blue. It is an optical double. But it is rather nice.

9. Theta Lyrae is very close by and it is another optical double. Magnitudes: A = 4.5. B = 10.1. Sep = 98.9". PA = 70 degrees. At 140X I could see its colours are yellow-orange and a stronger orange.

10. STT 352 in Lyra is new to me. It is a true binary. Magnitudes: A = 7.9. B = 9.4. Sep = 24.3". PA = 221 degrees. Easy split at 40X. A is yellow-white.

11. Finally I finished up with a double star with a mysterious designation: MMA 8.
It is a true binary. A = 10.5. B = 11.5. Sep = 27.2". PA = 299 degrees. At first I could see the 2 stars split at 112X. But I then discovered I see them at the lowly power of 40X. There are dim. So can anyone tell me who MMA refers to?

I did want to estimate the magnitude of U Lyrae. But my focuser was touching my alt-az mount. So I'll save it for another night.

Thank you for reading.

Best regards from Aubrey.

Hi Aubrey,

What a delightful report to read. It is nice to know someone managed some good observing over the past few days. You observed many delightful objects.  Your description of CN Boo is fascinating. During March of this year I observed and sketched Arcturus - you might recall that I spent quite a bit of Spring in and around Bootes. Anyhow, after reading your post I decided to look over one of those sketches to see whether I had included, and bang there it was. I had recorded it as TYC 1472-1427-1 on 19 March 2020, so very many thanks for bringing me down memory lane!

I'll see what I can find on MMA 8 - what an interesting designation.

All the best,

Darren.

Hi Aubrey,

In his Book 'Double & Multiple Stars, and How to Observe Them' James Mullaney states on page 98 that the IDS/WDS code MMA is designated to A. Van Maanan.  Adriaan Van Maanan was a Dutch - American Astronomer who lived between 1884 and 1946. He is best known discovering Van Maanan's Star. This star is a white dwarf, and here is a nice piece on it:

blogs.ucl.ac.uk/science/2016/04/13/hidde...ry-system/#more-2361

Enjoy!

Darren.

Until_then-Goodnight! wrote: Hi Aubrey,

What a delightful report to read. It is nice to know someone managed some good observing over the past few days. You observed many delightful objects.  Your description of CN Boo is fascinating. During March of this year I observed and sketched Arcturus - you might recall that I spent quite a bit of Spring in and around Bootes. Anyhow, after reading your post I decided to look over one of those sketches to see whether I had included, and bang there it was. I had recorded it as TYC 1472-1427-1 on 19 March 2020, so very many thanks for bringing me down memory lane!

I'll see what I can find on MMA 8 - what an interesting designation.

All the best,

Darren.

Please do come back to me about the MMA designation, Darren. 
But don't rush!
A lot has happened to you recently. 

Thank you from Aubrey.  

Hi Aubrey,

I've also discovered that van Maanan's star goes by the following names:

Van Maanen 2,
Wolf 28,
HIP 3829,
TYC 17-1272-1,
Gliese 35

I also like this article on van Maanan's star:

exoplanets.nasa.gov/news/1467/overlooked...dence-of-exoplanets/

Happy reading! 

Darren. 

Hello again, Darren.
I thank you very much for sending me these articles in regards to Adriaan Van Maanan.
Somewhere at the back of my mind I seem to remember coming across his name before.
So I am adding this designation onto my double star list.

I see TYC 17-1272-1 is positioned in southern Pisces.
Its magnitude is a very faint 12.6.
It is amazing that Van Maanan bothered to check out this particular star for so much
study.

Thanks again for providing me with so much information.
MMA 8 is a double star which might be worth considering to observe again. It is, after all, very near the carbon star U Lyrae.

Clear skies from Aubrey.