Visualization of moon distance variation and libration

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Menno555
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Visualization of moon distance variation and libration

#1

Post by Menno555 »

Had some fun with 2 captures I made of a 93% waning moon on 31 January 2021 and on 22 November 2021.

The full 5000px version of 22 November can be found here: https://i.ibb.co/LvDPyrh/maan-22nov-93.jpg

The captures were made with the same equipment (Meade LX200 8" f/10 ACF with Zwo ASI071MC Pro) at the same location, so I could compare everything very well.
I did use the Virtual Moon Atlas for the data and checking of orientation and size.
I made an animated GIF of the libration. I can explain that all here but this is way better and clearer: https://en.wikipedia.org/wiki/Libration
To show it clearly I made the 2 captures the same size cause as you can see in the image below, the moon was bigger/closer on 22 November then that it was on 31 January.

Image


And here the 2 captures besides each other for comparison of size at different distances.
maan-grootte-verschilsm.jpg
maan-grootte-verschilsm.jpg (425.83 KiB) Viewed 892 times
timh
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Re: Visualization of moon distance variation and libration

#2

Post by timh »

That worked very nicely Menno! Two moon images very close in phase and I liked the libration gif. My mental picture of an 8% size difference was that it was really 'not much' and so had thought of 'supermoons' as a bit of a hype in terms of interest but put side by side in the way that you have it is actually quite visually striking.

What were the conditions for the captures?

Tim
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Menno555
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Re: Visualization of moon distance variation and libration

#3

Post by Menno555 »

Thanks Tim!

The size of the moon due to distance indeed is no hype :) It's even an influence on how well moon captures can be done, depending on telescope and camera. A bit like Hubble which has difficulties with taking pictures of solar objects because they're too close. I did read something about it but can't find it anymore.
The conditions of 31 January I don't recall. The 22 November shot though was done with very good seeing. I used the Zwo ASI071MC Pro (too lazy to switch cameras :P ) with full resolution and could only use 10fps because of that. Did take 2 x 2000 frames (it's a 2 part mosaic cause it just doesn't fit in 1 FOV). Plus the Optolong L-eXtreme filter, so it's shot in Ha.

Menno
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admin
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Re: Visualization of moon distance variation and libration

#4

Post by admin »

Hi Menno,

that's really excellent and as Tim says is also very informative. I do like this sort of thing :)

Just wondering if you can make the GIF preview in the forums - try

Code: Select all

[img]URL[/img]


cheers,

Robin
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Menno555
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Re: Visualization of moon distance variation and libration

#5

Post by Menno555 »

Thanks Robin!
Somehow I always like to look what I can do with captures other then the capture alone.
And thanks for the tip on the animated GIF. I did change that in the original posting so you can remove it in your reaction if you want :)

Menno
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