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Moon - 8/4/22

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Moon - 8/4/22 was created by flt158

Hello everyone. 

I will be looking forward to observing the 7.6 day old Moon on Friday night 8th April which is in Gemini with my William Optics 158mm apochromatic refractor. We are supposed to have clear skies, calm winds and cold temperatures. 

There are going to be some interesting happenings with the Moon.

1. The Lunar X and presumably the Lunar V will appear right on the terminator at 20.20UT. That's 21.20 Irish Summer Time. 

2. A very strange star called SAO 78940 (HD 267257) will reappear from behind the Moon's very bright western limb at 19.52UT (20.52 Irish Summer Time). This 8.8 magnitude star has the ultra rare spectral class of K8. It ought to have a reasonably intense orange colour. I have never observed a K8 star. I know that the star is going to be extremely close to the western side of the Moon. But I'm looking forward to studying it all the same.

3. SAO 78973 (HD 52148) will be occulted by the Moon's eastern limb (the dark side) at 19.52 (20.52 IST). Its spectral class is a simple A2 and its magnitude is 8.8. 

4. Finally, SAO 78979 (HD 267827) will be occulted by the Moon at 19.54 UT (20.54 Irish Summer Time. Its magnitude is 8.1 and its spectral class is G5. So its ought to have a decent yellow colour. 

It could be a super night to remember - weather permitting. 

All the above information is from my Guide 9.1 DVD. 

I wish you all clear skies for this coming Friday night.    

Aubrey. 
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2 months 2 weeks ago #111103

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Replied by Fermidox on topic Moon - 8/4/22

Quite difficult to observe a 9th mag star at the bright limb I'd imagine Aubrey, best of luck with it all the same.

I'm a bit confused by the geometry - is the bright limb not the eastern side, as we look at it visually? Oceanus Procellarum is definitely on the western (left) side, and in darkness until the phase increases. Of course these directions can be reversed in a telescope.

Clear skies,
Finbarr.
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2 months 2 weeks ago #111105

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Replied by flt158 on topic Moon - 8/4/22

Okay, Finbarr.
The K8 star (SAO 78940) reappears on the bright side of the Moon as the Moon goes "backwards" in the sky. .
The occultations are on the dark side. 
You are right to say that all these stars are faint. 
They probably are near the faintest magnitude limits of our scopes. 
And yes - Oceanus Procellarum is on the west side of the Moon. 
It's clearly not visible until after gibbous Moon occurs.  

The Lunar X and V should look very good on Friday night.  

Clear skies from Aubrey.   
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Last edit: 2 months 2 weeks ago by flt158.
2 months 2 weeks ago #111106

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Replied by Until_then-Goodnight! on topic Moon - 8/4/22

Hi Aubrey, 

Very many thanks for sharing this information. 

Assuming the weather will be good, I'll be ready. 

Clear skies, 

Darren 
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2 months 2 weeks ago #111108

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Replied by flt158 on topic Moon - 8/4/22

I believe I have it sussed now, Finbarr and Darren. 

The western side of the Moon is closer to our eastern horizon. 
And the western side is in darkness okay. 
So the western side is doing all the occulting of these stars. 

But the eastern side is the bright side and it's nearer to our western horizon. 
And it's moving away from the K8 star SAO 78940. Confusing isn't it?

Still we shouldn't mind any of that.

Let us hope for clear skies on Friday night to see the Lunar X and V. 
By the way, our Celestial Calendar 2022 is saying that these 2 clare-obscure lunar features are going to be seen on Friday night. 
Many thanks to John Flannery. 

Thumbs up from Aubrey.    
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Replied by Fermidox on topic Moon - 8/4/22

I was surprised by how quickly the 'X' moved out of shape; I only got set up by 21.36, 16 minutes after maximum, and it was already less obvious. Anyway this was the result, the 'X' circled red and the 'V' in blue:



Clear skies,
Finbarr.
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Replied by flt158 on topic Moon - 8/4/22

Spectacular image, Finbarr!
Thank you for taking the time to produce it for us. 
Both the Lunar X + the V are perfectly shown.  
I will have my report tomorrow Saturday. 

Very best regards from Aubrey. 

 
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Replied by flt158 on topic Moon - 8/4/22

My small party with my wife Valerie, a friend called Mark, his son Matthew and daughter called Joy joined me in our back garden with my William Optics 158mm f/7 apochromatic refractor. 
I first observed the Moon at 20.30 local time (19.30UT). 
Even then both the Lunar X and the Lunar V were visible at 40x. 
That's a bit strange, because they weren't due to appear until 21.20 local time (20.20UT).
 I got lots of "Wows" as the young son and daughter saw both letters. 
And I got even more "Wows" when I increased the magnification up to 112x. 
I'm blessed that my 10mm eyepiece gives a full 37' fov. 
As a result the whole Moon fits in. 
I also saw 1 occultation.
The star SAO 78979 whose magnitude is 8.1 disappeared at 20.54 Local Time. I could even see some faint Earthshine at the time. 
At no time could I see the K8 class star called SAO 78940. It just proved too faint for my scope. But I didn't mind. It was an interesting experiment. 

The little ones were very happy to observe the quadruple star Castor split at 112x. 

And lastly, we all observed the scarlet coloured star R Leonis at 11x and 40x.
Over on www.aavso.org someone has agreed with me that its current magnitude is 9.0.  
It's nice to get it right.  

What a great night all round!

I've decided not to do any observing on Saturday night because I'm too tired.   

Very best regards from Aubrey. 
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Replied by flt158 on topic Moon - 8/4/22

It's official folks!
R Leonis is getting brighter. 
I have been checking it out on www.aavso.org 
Now all we need is clear skies. 
We have a lot of cloudy skies for the rest of this week. 
But once we get those clear skies you find R Leonis with even 10X50 binoculars very easily.
In other words, any optical instrument will succeed in finding it.  
It's just 5 degrees west of Regulus. 
What colour will it be when you find it?

Best regards from Aubrey. 
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Replied by Until_then-Goodnight! on topic Moon - 8/4/22

Hi Aubrey, 

Super report!

I'm delighted you had a nice night with your friends and wife. It is always special to share an nice experience with others. And you've definitely given me the impetus to observe that red star in Leo. 

Clear skies,
Darren. 
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Replied by Until_then-Goodnight! on topic Moon - 8/4/22

Hi Finbarr 

I love your image... You've captured the Lunar 'V' and 'X' so well... Congrats, and thanks for sharing it with us. 

Clear skies, 

Darren. 
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Replied by flt158 on topic Moon - 8/4/22

The night of the 6th June is the next opportunity to observe the Lunar X and V. 
Of course it will be weather dependent. 

Clear skies from Aubrey. 
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