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Some Venus Observations

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#1 chrisrnuttall

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Posted 24 January 2020 - 02:48 PM

Hi all

 

Venus is well placed for observation from my observatory for the next couple of months, until it starts to disappear behind the neighbour's house at around the time of quadrature. This means I can use my 12" scope to observe fairly regularly and I don't have to resort to the littl'un from other locations.

The seeing has been pretty good for me lately and I have had some unusually steady views just before sunset.

The ADC really helps with the image sharpness, and when used with the apodizer and W47 violet filter, the planet stands still and well resolved in the eyepiece.

I can push the magnification up a little, and if I shade my eyes against the day lit sky, subtle shading and streaks then start to become apparent over the planet's disc.....

 

Attached Thumbnails

  • Veuns 2020 01 12.jpg

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#2 chrisrnuttall

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Posted 24 January 2020 - 02:49 PM

The 18th was not as good as the 12th, but still a very decent view.

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  • Veuns 2020 01 18 low.jpg

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#3 niteskystargazer

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Posted 24 January 2020 - 03:02 PM

Chris,

 

Nice sketches of Some Venus Observations smile.gif .

 

CS,KLU,

 

thanx.gif ,

 

Tom



#4 frank5817

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Posted 24 January 2020 - 03:04 PM

Chris, 

 

Thank you for posting these here. Excellent detail in the cloud brightness variation.

Very nice.

 

Frank :)



#5 alvarete

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Posted 24 January 2020 - 03:37 PM

Hi Chris,
it is a real luck that you had post this sketches!
After 30 years of observing this planet with a lot if telescopes I was decided to do not give it mote opportunities to show me its clouds.
I was saying myself that it was not possible tu see clouds in visual. Last years I use 5" and 6" apos and 8" MN.
I will try it some more times!
Any concern besides violet filter??
Fantastic sketches

#6 chrisrnuttall

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Posted 24 January 2020 - 04:21 PM

Alvarete

 

OK here are all the factors I find helpful in observing details on Venus....

 

I find the W47 violet filter to be very useful on Venus, I do sometimes use the W29 deep red filter but to me there is never as much detail with this one. Other observers report different results and I suspect that I am more sensitive to the violet end of the spectrum than to the red end.

David Gray uses a stack of green filters to good effect in his Venus observations.

You could try different colours and see what works for you.

The filters not only restrict the light to one part of the visible spectrum, but importantly they reduce the brightness of the image so that it is possible to see the very subtle variations in brightness of the cloud tops. Using a dark filter (appropriate to your telescope aperture) really helps.

 

I use an apoziser which I find always improves the image steadiness no matter what the conditions are like, but has the side effect of reducing colour saturation. Apodisers work better on larger telescopes. I also have one for my 5" mak but it doesn't improve the view in that telescope at all. I would think that using one on your 8" would be of some benefit.

 

For a year now I have been using an Atmospheric Dispersion corrector, and have found that it improves image sharpness on every planet I use it on, even Uranus and Neptune showed a clear benefit and they were quite high in my sky. For lower altitude observing the ADC is excellent in all telescopes, it can transform an unobservable ball with bad colour dispersion into a pretty decent disc.

 

I have also used a range of telescopes on Venus. 5" Maksutovs, 8" Newtonians, 12" Newtonian. The larger aperture telescope always wins on planets. I only own a smaller scope for occasions when I can't point my large scope at the planet I want to observe so I must travel to different location with a better horizon.

 

Lastly I always try to observe when Venus is high in the sky. I start before sunset (making sure the sun is behind a building) using go-to, or setting circles, or even just a digital angle finder to point the telescope in the right direction. You need the best seeing you can get.

 

Good Luck!


Edited by chrisrnuttall, 24 January 2020 - 04:24 PM.

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#7 Sol Robbins

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Posted 05 February 2020 - 11:51 PM

Great sketched observations. They pretty much match my own using variable dielectric neutral density filter,

(V-DND) in my 8" reflector. Thanks for sharing them.



#8 sunnyday

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Posted 05 February 2020 - 11:56 PM

nice work 



#9 Aquarellia

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Posted 06 February 2020 - 01:38 AM

Oh, whaw I like it!

Your sketch quality and the "travel sketch book" style you use are fantastic!

Indeed I have eye concern with the W47 on Venus, as well with the Calcium filter on the sun, however no issue to look through a Halpha filter or to avoid purkinje effect on the Betelgeuse visual estimation.

Anyway Bravo for your sketches and all your CN gallery here.

Michel



#10 DDEV

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Posted 09 February 2020 - 08:14 AM

Hi Chris,

Two fine sketches if Venus, equally great descriptions. Well done!

#11 Special Ed

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Posted 09 February 2020 - 04:06 PM

Chris,

 

Beautifully rendered observations of our sister planet.  smile.gif 

 

What media are you using?  It looks like color paper and pastels.



#12 chrisrnuttall

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Posted 14 February 2020 - 02:51 PM

Hi Michel

 

the sketches are done with pastel pencil on velour paper.

I print out the blank disc first before filling in the details,




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