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Mars and Uranus on 17th Feb.

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#1 stanislas-jean

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Posted 18 February 2019 - 03:57 AM

Hi,
Here is a mars report performed on 17th last with the 127mm apo refractor.
Average to less images were met at the eyepiece.
Thaumasia was bright with the red filter, solis lacus was not seen (but the seeing presence), The south pole area appeared slightly witish, Eridania was whitish clear.
The north pole area exhibited again a whitish hood spreading on the terminator.
A whitish hazze was spreading on the volcano area, tharsis and olympica at the limb.
Globally the limb was bright on the red channel all along the limb on a thin width.
The atmosphere looked misty on the limb.
Difficult to say more in first due to the seeing level and second due to the disk size.

 

resized_mars 17.02.19 18H10UT.jpg

 

Here is the report of Uranus performed with the 127mm refractor and the 235mm cassegrain.
Images were poor to average in the 127mm average only on very short times in the 235mm.
The pole appeared bright, the temperate zone greyish, darker away the equator.
Difficult to say more with regards the seeing conditions, sky transparency was exceptionnal.

 

resized_uranus 17.02.19 18H35UT.jpg

 

 

Good skies
Faithfully.
Stanislas-Jean.


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#2 agmoonsolns

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Posted 18 February 2019 - 04:07 AM

Wonderful drawings and details!



#3 niteskystargazer

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Posted 18 February 2019 - 05:41 PM

 Stanislas-Jean,

 

Nice sketches of  Mars and Uranus (On 17th Feb.smile.gif .

 

CS,KLU,

 

thanx.gif ,

 

Tom



#4 frank5817

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Posted 18 February 2019 - 10:24 PM

Stanislas-Jean,

 

Very nice work.

Always a pleasure to see your posts and details included.

 

Frank :)



#5 stanislas-jean

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Posted 19 February 2019 - 06:49 AM

Thanks a lot Frank, Tom and Agmoon, gents for their like also.

 

As the sky is now on the period uncloudy,

Here is a report of Mars performed last 18th with the 150mm cassegrain.
Almost good images were met at the beginning.
With comparison with the 17th observation, in fact nothing was actually different, still the brightness on Thaumasia-Daedalia on the red channel.
Eridania-Ausonia was rather whitish both yellow-green and blue channels.
Hazze on both pole area.
This is a difficult observation with regards of the disk size and the seeing conditions. The sky was covered with thin cyrrus clouds being also an obstacle for observing clearer all the contrasts.
Nothing more.

 

Comment: the Thaumasia-Daedalia area showing a brightness on the red channel will now obligatory means a dust storm, because seen also on the yellow green channel. My opinion is that this more an albedo effect of the local groung being subject to past very recent dust storm. The surface was eroded and fresh sand is appearing making this effect.

This is probable but here the color filter procedure is exhibiting its limits. Some additionnal procedure should be employed as the polarimetry of light. Fresh eroded ground should exhibit polarisation angles where the reflected light will be the highest, dust storm doesnot exhibit such marked ratio. This needs a bigger apperture say 300mm and stable images. Quite undertakable by amators well equipped and located on good sites.

This is adding but sometimes this is also on fault regarding the status of the investigation.

Have good receipt of the present post.
Faithfully.
Stanislas-Jean

 

resized_mars 18.02.19 18H00UT.jpg


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#6 frank5817

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Posted 19 February 2019 - 02:10 PM

Stanislas-Jean,

 

Nice Mars sketches from a short time back.

I am surprised that I am not having luck with the weather and steady seeing.

Glad you are.

 

Frank :)



#7 stanislas-jean

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Posted 21 February 2019 - 03:24 AM

Again, this is a matter of contrast transfer of the optical chain, scope design and eyepiece indeed, sky seeing acting as a degrading filter.

To-day a 5-6" can be used but of a very high strehl ratio supporting 300x minimum, with moderate obstruction or no. The best times for having the best images needs to be researched indeed. To-day at the sunset time preferably.

That's it.

Thanks gents for your interest and likes.

Faithfully.

Stanislas



#8 Special Ed

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Posted 22 February 2019 - 09:42 AM

Stanislas,

 

Good observational sketches of a very difficult target at this apparent diameter.  I think the dust on Mars is so fine it takes a long time to settle out back to the ground after a big storm like the one last year.

 

I wish I could add an observation but we are in our typical winter weather pattern here--a train of storms one after another coming across the US from the west and southwest...



#9 stanislas-jean

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Posted 22 February 2019 - 12:04 PM

Thanks Michael for your post.

Frankly, even if the contrast feature of the main formations are rather lower than "normal", this is not due to a dusty remaining atmosphere. It is indeed but probably not enough for producing such contrasts. We are after few months of the major storm that had eroded lot of surfaces. There was occuring some secular changes on the IUA recognised chart of mars. This had modified strongly the roughness of the ground surface having albedo variations with the sun ray angles.

On the Thaumasia area the brightness noted on red color is something spectacular, being not a dust hazze, my opinion but the described albedo variation locally. Observed near the limb location: at the meridian?

The problem between observers, this is the fact that we have not the same references, the same grey scale on a color channel. This is making difficult comparison between documents of different time shot on a same planet rotation.

Now about the dusty ratio into the mars atmosphere, I presume this is a permanent fact, the ratio diminishing, not only by gravity but more captured by the white hazzes, white hazzes circulating through the seasons from a pole to the opposite.

Sothat I think the hazze activity should be a must, on the period rather a mist activity.

This is more the white hazze that clean the atmosphere, a stronger media.

My opinion.

Faithfully.

Stanislas



#10 stanislas-jean

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Posted 23 February 2019 - 10:46 AM

Yeah?

Is there somebody who can make opinion about the mars atmosphere figure on the period?

Other than statistical ones.

Thanks and welcome.

Faithfully

Stanislas



#11 stanislas-jean

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Posted 24 February 2019 - 05:55 AM

Here is a report of Mars performed last 23th with the 235mm cassegrain under average images.
Argyre was bright whitish up to the limb, Electris too on the terminator.
The Solis Lacus area (on Thaumasia didn't show a bright patch on the red channel.
Both poles area were hazzy whitish, Nix Olympica area covered by a whitish hazze.
Nothing mare noted.
An average observation, but added some confirmation expected for the red channel status of Thaumasia.

 

resized_Mars 23.02.19 18H30UT.jpg

Faithfully
Stanislas-Jean
 


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#12 stanislas-jean

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Posted 05 March 2019 - 02:34 PM

Hi,
here is a report of mars performed with the 150mm refractor under average good images.
Have a look on the sketch for showing the whitish area: argyre, hellas, chryse-xanthe (not probably hazzy) and the both poles area under whitish hazze.
The main formations were well captured with a good accessible contrast with regards to the planet disk size of 5.17".
The planet is well placed in sky at sunset sothat when the seeing cooperate, somthing can be still undertaken.

Hope the seeing will be a step better days later that this evening.

Not a big concern for the follow-up but remains with a 150mm aperture.

Good skies.

Stanislas-Jean

 

resized_mars 05.03.19 18H30UT.jpg


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#13 stanislas-jean

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Posted 08 March 2019 - 02:26 AM

Here is a report of Mars performed on the 7th of march with the 235mm cassegrain and under just average images.
Notes are incorporated on the sketch: nothing fundamentaly different than the 5th march observation.
Seeing and wind were a little too present.
Probably one of the last report from here.

Good skies

Stanislas-Jean

 

resized_mars 07.03.19 18H30UT.jpg

 


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#14 stanislas-jean

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Posted 08 March 2019 - 02:22 PM

thanks a lot gents for your likes.

Feel Mars observation is not still over in spite of the tiny disk size.

Stanislas-Jean



#15 stanislas-jean

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Posted 11 March 2019 - 04:05 AM

Hi,

Here is a report of mars performed on the 10th with the 127mm apo refractor.
Images were average to good enough on small times (say 7/10).
Syrtis Major was there with unequal albedo (probably covered by a thin hazze), the limb of the planet was hazzy occulting Mare Thyrenum.
Hellas was bright whitish with the W11 and W80A filters, brightness fades with the W8 filter. Was probably misty but this needs more investigations. As well for the Xanthe area where the extension of the brightness looked over the said Xanthe area.
Both poles area were hazzy whitish.
I reassessed the refractor for a complete settlement yesterday, the triplet lens cassette, the alignment of the tube and the collimation. this helped the production on this report (say a 5" size aperture on a 5" planet disk size still capable!).
Good skies
Faithfully.

Stanislas-Jean

 

resized_mars 10.03.19 18H25UT.jpg


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#16 stanislas-jean

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Posted 11 March 2019 - 02:45 PM

Until the sky is open clear, even agitated with seeing, the follow-up is continuing.

Here is the mars report of 11th march performed with the 127mm refractor.
Images were average but enough to collect the main features.
Whitish hazze on both poles was still there, Hellas white appeared at the first look.
The extension of Xanthe was not captured with comparison with the 10th report (difference of CM 9-10°). This may show a presence of whitish hazze on the slot Xanthe-Chryse (an expectation).
Syrtis Major is still of unequal overall albedo, a thin veil should lower its contrast, as well on the limb.
Sinus meridiani was captured clear, so this make thinking a clear terminator.
Globally a difficult observation dur to the seeing presence.
Good skies
Stanislas-Jean

 

resized_mars 11.03.19 18H25UT.jpg


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#17 stanislas-jean

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Posted 15 March 2019 - 07:11 AM

No comment more or objection, so nothing more will be added.

Means not this is stopped.

See the http://alpo-j.asahik...Latest/Mars.htm

for the last details.

Glad to see only very few gents publising documents.

Sorry, seasons  are on change, but for who.

So Uranus images by imagers are on fuzzy results, smiling!

Imagers are on flu?

Unable, I think they would done, but unable to.

Just goto as on a mount.

Sorry for the imagers, but for scientific targets they would do. Japaneesse did as they could. Congratulations to them all!

Stanislas-Jean




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