Venus in UV 6.8.2017

[Pete Presland]

An extremely early rise this morning 3.15am, around an hour earlier than necessary! Lovely morning though with Pleiades, Hyades on display.

I had to wait well over an hour for Venus to rise above the rooftops.

20,000 frames taken with my C9.25, ASI120mm, and X2 Barlow. Nice to see a little surface detail visible.

[Dave In Vermont]

Very good take! Of course, it's not actually 'surface' detail directly - it's clouds. But it seems likely that this nearly constant-in-same-location variation in the clouds, visible in UV, is due to typography of the surface below. Or so goes one theory at least.

There was one notable fluctuation in the clouds on Venus recently - around the beginning of the year - which caught many people's attention. It was being referred to as a 'wave' of some form. I'll post an image below.

Keep trying to skin this 'onion-of-a-planet!'

Thank you!

Dave

 

 

[Paul73]

Well worth the early start!

I didn't know that anything other than a uniform disc/crescent was possible.

Paul

[tooth_dr]

Amazed that you see details in the atmosphere! Great capture well done. 

[Pete Presland]

4 hours ago, Dave In Vermont said:

Very good take! Of course, it's not actually 'surface' detail directly - it's clouds. But it seems likely that this nearly constant-in-same-location variation in the clouds, visible in UV, is due to typography of the surface below. Or so goes one theory at least.

There was one notable fluctuation in the clouds on Venus recently - around the beginning of the year - which caught many people's attention. It was being referred to as a 'wave' of some form. I'll post an image below.

Keep trying to skin this 'onion-of-a-planet!'

Thank you!

Dave

 

 

Thank you Dave for the info, not very well described on my behalf. I did now it was cloud as i have captured it before, but i did wonder why we always seem to have the same view. I have captured some better detail before, but i think more aperture or even better conditions are needed.

Thanks again for the info Dave, where did you get it?

[MarsG76]

There's definitely cloud details coming through... 

Even though unfortunately the corrector plate on SCTs block a lot of UV light but you still captured a good deal of cloud detail.

[Dave In Vermont]

8 hours ago, Pete Presland said:

Thank you Dave for the info, not very well described on my behalf. I did now it was cloud as i have captured it before, but i did wonder why we always seem to have the same view. I have captured some better detail before, but i think more aperture or even better conditions are needed.

Thanks again for the info Dave, where did you get it?

Hi Pete -

Where? Not absolutely certain as I use several (reputable) sources of astro-news everyday. Might be 'Sky & Telescope' magazine's website, but it was widely reported - even making it's way up to the main-stream news. It caught their attention as it was so unusual to see that same-as-always' planet display anything different. Weird & different sells newspapers being the paradigm.

I have one of the first Schuler UV Venus-Filters - from back when we amateur-astronomers' first began capturing that pattern in the clouds of Venus - and I know what you mean when you said "... i did wonder why we always seem to have the same view." It's been the same since around 2000.

I have an idea of how we might be able to see Venus and the clouds in far better detail - send Astrovani (Avani Soares) a UV-Filter & stand back!  

Happy Hunting!

Dave

 

 

[Merlin66]

The UV transmission of the white glass SCT correctors isn't as bad as you may think. Bear in mind that the efficiency of the CCD cameras drops dramatically below 400nm also.

I have successfully recorded the spectrum of Sirius down to 365nm with both my C11 and the ol' Genesis.

 

[Dave In Vermont]

Look what I just found in my 'Miles-O'-Files' -

 

 

This .GIF is over a topographic map of the underlying surface area of the wave-effect in the atmosphere over Venus. I don't remember which publication it came from, but something tells me it was the JPL of NASA.

Dave

[Pete Presland]

I have been thinking about maybe a large (300mm) newt for Planetary imaging in the future. I do look at the large central obstruction and think the 235mm aperture is not as big as it appears on the C9.25.

[Dave In Vermont]

True, Pete - but when you see all the book's referencing this photo and that and name the telescope used - that telescope, too, is with a similar central obstruction. So you move-up to more aperture - and guess what? It has an even larger central-obstruction!

The only way truly get around this problem is to get a huge refractor. But even then - you've got another major obstruction: You had to sell your children into slavery to pay back the bank loan you took out to buy the 8" F15 refractor!

Or - you learn to live with the fact an 8" SCT is really about 6" of clear aperture as it's normal state-of-affairs.

You can't win!  

Dave