16 replies to this topic

[DMach]

I managed to get my telescope downstairs last night to capture some frames on Venus. Pretty rough-and-ready, no time to check collimation. Had my 3yo daughter keeping me company, which was nice. No features to be seen here, a I was imaging in visual only.

 

 

Early this morning, I dragged myself out of bed at around 4:45am to check out the quality of the sky. There were some fast-moving clouds around which, from experience, spelled danger ... this often worsens towards dawn (more than once at the precise moment I've finished setup and collimation and am about to start imaging). I was feeling pretty tired and looking for an excuse to go back to bed. However upon observing the stars, it looked like seeing was potentially pretty good.

 

So, after a period of internal struggle, I decided to give it a go.

 

I ended up spending most of my time on Jupiter. The slow seeing (or "fizzing" as Darryl calls it ... a very descriptive term!) was not as bad as previous sessions this year, and in between those moments of complete blurriness the fast seeing was good, bordering on excellent. So I was hopeful of some good results.

 

See what you think!

 

The best of the Jupiter captures:

 

 

To my eye, there seems to be flecks of orange cloud material heading back down the STZ, possibly from the GRS?

 

There is also a raft (?) of light brown cloud along the southern edge of the STZ, surrounding a white oval. This is more easily seen in an earlier image from this session:

 

 

And some frames I captured of Saturn as dawn was starting to break, which featured some nice, contrasty bands (albeit with the polar hexagon not quite as defined):

 

 

Usual equipment: C11, ASI290MC, PowerMate 2x, ZWO ADC, UV/IR cut filter

 

Thanks as always for looking!

Edited by DMach, 04 April 2020 - 10:09 AM.

[Tulloch]

...

 

So I was hopeful of some good results.

 

See what you think!

...

What do I think? Absolutely stunning, that's what I think. I especially looking forward to what you can do in a couple of months, when the sizes of these planets will increase by, what, 25% or so?

 

I also like that these were created using a focal ratio higher than the accepted value of 5x pixel size, these are closer to 7, aren't they? What is the effective f/l of your setup?

 

Is there a bright white line just under the GRS, or am I seeing things?

 

Thanks for posting, Andrew

[DMach]

What do I think? Absolutely stunning, that's what I think. I especially looking forward to what you can do in a couple of months, when the sizes of these planets will increase by, what, 25% or so?

 

I also like that these were created using a focal ratio higher than the accepted value of 5x pixel size, these are closer to 7, aren't they? What is the effective f/l of your setup?

 

Is there a bright white line just under the GRS, or am I seeing things?

 

Thanks for posting, Andrew

Thanks Andrew.

 

Yes, with the 290MC I'm pushing 7x the pixel size, which is pushing the recommend boundary and likely "wasting" some photons in all but excellent seeing. In hindsight I should have bought the 224 lol.

 

Rather than a white line under the GRS, I think there may be lines of coloured cloud in the STZ?

Edited by DMach, 04 April 2020 - 06:53 PM.

[sunnyday]

absolutely beautiful these photos.
thank you and well done.

[Kokatha man]

<"I ended up spending most of my time on Jupiter. The slow seeing (or "fizzing" as Darryl calls it ... a very descriptive term!) was not as bad as previous sessions this year, and in between those moments of complete blurriness the fast seeing was good, bordering on excellent. So I was hopeful of some good results.">

 

Fizzing or not, your results (& the seeing) really were excellent at this time of the year Darren     - as long as you can get around 1500+ frames or thereabouts then the good 'uns will deliver...as these Jovian & Saturn images have!

 

ps: You ought to have targeted Mars with that sort of seeing! 

Edited by Kokatha man, 04 April 2020 - 07:42 PM.

[John_K]

Excellent images!

 

Clear skies.

 

John K.

[Tulloch]

Thanks Andrew.

 

Yes, with the 290MC I'm pushing 7x the pixel size, which is pushing the recommend boundary and likely "wasting" some photons in all but excellent seeing. In hindsight I should have bought the 224 lol.

Yeah, well, as far as I'm concerned that 5x number's just a indication for green light based on an assumption about 2.75 pixels per FWHM. The proof also says use higher values for colour cameras and in better seeing. Your seeing appears to be excellent as is your processing, so bring on 7x and more pixels !

Attached Thumbnails

• 

[Kinga]

Excellent!

[DMach]

absolutely beautiful these photos.
thank you and well done.

 

 

Excellent images!

 

Clear skies.

 

John K.

 

 

Excellent!

Thank you all!

[DMach]

<"I ended up spending most of my time on Jupiter. The slow seeing (or "fizzing" as Darryl calls it ... a very descriptive term!) was not as bad as previous sessions this year, and in between those moments of complete blurriness the fast seeing was good, bordering on excellent. So I was hopeful of some good results.">

 

Fizzing or not, your results (& the seeing) really were excellent at this time of the year Darren     - as long as you can get around 1500+ frames or thereabouts then the good 'uns will deliver...as these Jovian & Saturn images have!

 

ps: You ought to have targeted Mars with that sort of seeing! 

Thanks Darryl.

 

Each stack was a little under 1,000 frames in this case, but then of course de-rotating multiple images (6 in this case) effectively increases the total data. Thankfully the conditions persisted during this session to allow this.

 

Regarding Mars, that was my thought given the conditions. But as it happened:

1. I spent longer than planned on Jupiter as the seeing was improving as time passed.
2. My kids had woken up by that stage, so I had to wrap things up.
3. My kids love looking at Saturn.
4. I'm a complete marshmallow when it comes to my kids.

 So Saturn it was lol. 

[Tom Glenn]

Really fantastic stuff Darren!  

[DMach]

Really fantastic stuff Darren!

Thanks Tom

[Foehammer]

Superb images Darren! Well done!

[DMach]

Superb images Darren! Well done!

Thank you!

[lynnelkriver]

Oh my these are amazing!  All the best, Scott

[DMach]

Oh my these are amazing! All the best, Scott

Thanks Scott, appreciate the kind words.

[DMach]

By the way, I've just realised I (brilliantly) managed to attach the same Jupiter picture twice in my original post.

 

Here's the version from earlier in the session which shows the "raft" of light brown cloud along the southern edge of the STZ, surrounding a white oval:

 

 

Seeing was not as good at that stage, plus I may have missed focus by a tick.