July Solar Challenge

An archive of all the best images Solar Chat has to offer!
Post Reply
User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

July Solar Challenge

Post by Montana »

Dust off your January perihelion images from around 4th January (doesn't have to be exact!) and check what equipment you used to get a full solar disc.

Now image the full solar disc with the same equipment around aphelion day on the 4th July.

Post your images here, let's see some amazing imaginative presentations to show the solar size differences :hamster:

If you forgot to take an image in January, don't worry, the next perihelion is just 6 months away on 4th January 2023, so get snapping away :beanie:

https://www.timeanddate.com/astronomy/p ... stice.html

Alexandra


User avatar
DeepSolar64
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 18728
Joined: Thu Sep 05, 2019 12:19 am
Location: Lowndesville S.C.
Has thanked: 17458 times
Been thanked: 16550 times

Re: July Solar Challenge

Post by DeepSolar64 »

I have some close to aphelion ones now come perihelion in 6 months I'll have to do this! I'll use the SMII60.


Lunt 8x32 SUNoculars
Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces

Image Visual Observer
" Way more fun to see it! "
User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

Re: July Solar Challenge

Post by Montana »

I have finally processed my images from Sunday and I had a play this evening. Not perfect but it was the thought that counts :)

Image2022-07-03 CaK solar disc ap and peri size by Alexandra Hart, on Flickr

Image2022-07-03 Halpha solar disc peri and ap size by Alexandra Hart, on Flickr

Image2022-07-03 WL solar disc Peri and Ap size f colour by Alexandra Hart, on Flickr

Alexandra


User avatar
DeepSolar64
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 18728
Joined: Thu Sep 05, 2019 12:19 am
Location: Lowndesville S.C.
Has thanked: 17458 times
Been thanked: 16550 times

Re: July Solar Challenge

Post by DeepSolar64 »

Very nice Alexandra. The apparent size difference is easy to see.


Lunt 8x32 SUNoculars
Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces

Image Visual Observer
" Way more fun to see it! "
User avatar
Averton
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1775
Joined: Wed Jun 01, 2022 1:35 pm
Has thanked: 3303 times
Been thanked: 2311 times

Re: July Solar Challenge

Post by Averton »

Very nice presentation of very nice images Alexandra :)


Clare & Peter
User avatar
Averton
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1775
Joined: Wed Jun 01, 2022 1:35 pm
Has thanked: 3303 times
Been thanked: 2311 times

Re: July Solar Challenge

Post by Averton »

We didn't have an image from 4 January, the closest was 29 December but we did take an image on 4 July.
Both images are taken with our 72ED with a Meade white light filter and an ASI178 camera.
The apparent diameters of the sun are taken from Stellarium on date and time of the image capture.
The pixel measurement of the images was done in GIMP.
2021-12-29 2022-7-4 Perihelion Aphelion difference small.jpg
2021-12-29 2022-7-4 Perihelion Aphelion difference small.jpg (193.9 KiB) Viewed 1809 times
For a full size image see https://www.flickr.com/photos/153787832 ... 203787441/


Clare & Peter
User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

Re: July Solar Challenge

Post by Montana »

That's excellent!!! a great presentation and easy to see the difference :bow :hamster:

Alexandra


User avatar
Averton
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1775
Joined: Wed Jun 01, 2022 1:35 pm
Has thanked: 3303 times
Been thanked: 2311 times

Re: July Solar Challenge

Post by Averton »

As an interesting additional exercise we calculated the FOV of our 72ED using the ASI178 camera.
We then determined the percentage of the FOV required by the sun at perihelion and aphelion and then the pixels used in each case.
Our 72ED actually has a focal length of 432.7mm at focus with this camera as measured by our astrophotography software.

Focal length 72ED 432.7
ASI178 X dimension (mm) 7.4
ASI178 Y dimension (mm) 5
ASI178 X pixels 3096
ASI178 Y pixels 2080

X FOV (min) 58.7920640254415
Y FOV (min) 39.7243675847578

Sun apparent dia Perihelion (min) 32.5145
Sun apparent dia Aphelion (min) 31.4488

pixels used to display sun @ perihelion 1712.21904977581
pixels used to display sun @ aphelion 1656.09910816988

This gives an answer very close to the measured values on the two images.
1712 vs 1711
1656 vs 1655
Quite surprising :)


Clare & Peter
User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 14171
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK
Has thanked: 8352 times
Been thanked: 8103 times

Re: July Solar Challenge

Post by Carbon60 »

Good challenge, Alexandra.

Here's my contribution. I have to confess that the scales may not be perfect as I make mosaics and crop when I create my original images, so the actual image scale changes every time. Therefore, these are more art than science. Also, I couldn't image 'on the day' because of the weather, so 'my Aphelion' image was taken a week after the actual Aphelion.

Anyhow, here we go:

ImageAphelion_Perihelion_CaK_2022 by Stuart Green, on Flickr

ImageAphelion_Perihelion_Ha_2022 by Stuart Green, on Flickr

Stu.


H-alpha, WL and Ca II K imaging kit for various image scales.
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/
User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 14171
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK
Has thanked: 8352 times
Been thanked: 8103 times

Re: July Solar Challenge

Post by Carbon60 »

Montana wrote: Fri Jul 08, 2022 8:11 pm I have finally processed my images from Sunday and I had a play this evening. Not perfect but it was the thought that counts :)

Alexandra
Really nice, Alexandra. I like the ‘3D feel’ to these.

Stu.


H-alpha, WL and Ca II K imaging kit for various image scales.
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/
User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

Re: July Solar Challenge

Post by Montana »

Great presentations Stuart :bow :hamster: I don't think it really matters about exact timings because the Sun and Earth take 6 months to move close and apart :) also, mine are mosaics too, I bet that won't make much difference either :) it is the fun that counts.

Alexandra


User avatar
DeepSolar64
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 18728
Joined: Thu Sep 05, 2019 12:19 am
Location: Lowndesville S.C.
Has thanked: 17458 times
Been thanked: 16550 times

Re: July Solar Challenge

Post by DeepSolar64 »

Nice work Stu! The difference is easily seen. 👍🏻


Lunt 8x32 SUNoculars
Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces

Image Visual Observer
" Way more fun to see it! "
Post Reply