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Jason, I hope to see more of your work. Glad I picked up sketching last year, it's rather an enjoyable aspect of our hobby. Personally, I prefer it to imaging - in that it's a very manual labor of love. And it requires patients and actually teaches us to look closer at our subject...preferably in good seeing. (Imaging is a labor of love, too, and require patients and a different skill set, of course. Anyway...)

Look, we have all seen Jupiter in Ant IV seeing. What can I say, you nailed it.

What's striking, however, is you mentioned some mild undulation in the NTB under those conditions. Wish I could comment on them, but it speaks to what you would have seen in better conditions. I am not familiar enough with Jupiter at various times UTC to know what CM you are observing. We could look it up. But, surly those are festoons. There seems to be a lot of them this season.

Something struck me, a question, one night under similar conditions. Does seeing affect color? Probably...just not sure how. Anywhooo...

I find both polar regions essentially featureless, too. On occasion, there are some faint bands. But you noted some darkening, that's incredible, actually. There are some, but I found it takes very good moments of seeing just to glimpse them.

On a method, I dunno. Your pencil work looks quite good. I am sure you will fall into a suitable method. I use PC paint programs because I do not have a scanner at home. When I was working, scanning was easy...but not at 2AM when I am trying to get my sketch up. So, I fell into using PC paint programs. You will find a method. I hope.

Criticism? A dozen sketches in six years is not enough, especially for someone with 35 years of illustrating experience. If you wish, you can calculate the CM here.

http://www.arksky.org/tools.htm

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Thank you very much, Norme. I enjoy the tedious process of waiting for details to present themselves. And, frankly, sketching does force us to see things we may otherwise overlook while simply glancing.

Regarding color, IME the aperture of the instrument makes a large difference, as does the transparency of the sky. I'm sure seeing plays a part, as well. Rare nights are those with good seeing, transparency...and no Moon. I've done sketches with my [now disassembled] 12" dob that revealed much in the way of rust, rose, beige and cool gray. This morning, with my 4", I'd say the only color I recall was an overall gentle yellowish warmth. I am in the throes of a 10" Newtonian reflector project, which will be semi optimized for subtle contrast work (26% CO, downward active cooling, flocking in every nook and cranny, baffled focuser, etc...). It will be GEM mounted (like my 4") to appease my desires of sketching. I do hope it will bring some of the colors back that I am used to seeing on the Jovian surface.

I do have a question for you. You mention the "CM", which I assume to be the Central Meridian. What does this mean for Jupiter observing? Is is a way of cataloging my sketch time with better reference accuracy? I used the two links at the top of the page you "linked", but I don't really understand the numbers it gives me.

Thanks again!

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Looks great Jason, nothing feeble there at all.

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The reason I asked about color is because the Festoons are quite blue, stunning actually. But seems only when the seeing settles. Color in a 6" is very unsaturated almost grey tone. But it is there. Just a thought having coffee observing Jupiter the other night.

Yes, Central Meridian. I guess it just helps pin down where we were looking. Actually Jupiter has three measurements, much to do with the varying speeds of rotation in different latitudes, as I understand it. It's really not necessary to put it on there. I put them in sometimes, if someone wants a reference.

Nuther question...you mentioned the moon being close. Jupiter is darn close tonight. Really the moon didn't seem to bother it, but I am sure it must. You got extra photons coming in on top of those from Jupiter. There should be some contrast loss, even if not detectable?

A 10" GEM mounted...sweet, Jason.

Just got back form watching the GRS rotate over the preceding limb. Might sketch tomorrow. Tired to glimpse the Cat's Paw, but settled for the 3 Astronauts.

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Thanks for the CM explanation.

The moon doesn't really effect the 4" scope directly...well, not too much. Scatter is kept to a minimum thanks to a well baffled tube. I think it was the continually passing thin cloud cover which was glowing from the Moon light that disturbed the view. Although it did occasionally help to reduce the contrast of the NEB in such poor seeing, which is how I was able to finally confirm the trailing bulge/festoon in the image. For the first few minutes of observation I only saw the second and third bulges.

BTW, I just got back from a bicycle ride, coffee sounds good.

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hi Jason,

nice work with 110mm !
The transit looks great.

Bye Christian

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Thank you, Christian. I plan on eeking as much out of this scope as I can until I get my 10" off the ground. For a small newt it doesn't do too badly: 1/10 PTV primary, 1/23 PTV secondary, 22% central obstruction...if I could only get some laminar airflow in this darn atmosphere.

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Constructive criticism is welcome

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Hello Jason,

This is a fine sketch of Jupiter. Always nice to catch a Moon shadow on the clouds.

Frank

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Jason, don't get me started on baffles. (Long story.)

Laminar airflow? Move to the tropics. Or Miami is supposed to have it, too, so you're pretty much tropical. I am in the far east at 16 degrees north. Dry season rules with 8/10 seeing or better most nights (at least last year.)

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Trust me, between my love of planets and my obsession with bird photography I'd love very much to have a place in Florida. I'd be lying if I said I hadn't thought about it more than once.

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