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The best & worst of seeing: Neptune last night from home...

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#1 Kokatha man

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Posted 21 October 2017 - 04:39 AM

Ok - ok! Another Neptune set of images! rofl2.gif


I was just saying to Pat that we have 84 images (including animations) of Neptune on the PVOL site alone since we started concentrating upon this most distant planet 3 years ago...they sure have tallied up very quickly! wink.gif


Whilst only a casual fisherman, this night (last night) was probably one of those "the one that got away" situations tbh. wink.gif


The forecasts weren't any better than the last 2 imaging sessions from home (14th & 17th) as far as surface winds & jet-streams were concerned - but the transparency was supposedly high & I had a feeling it might be a good night...


Arriving home late from Murray Bridge we set up (had taken everything down from the 17th due to rain one evening ) & quickly iced up the scope to get the temperature down...& just after true darkness were plugging the laptop etc in: looked up & suddenly realised the sky was full of clouds..! bawling.gif 


We waited for about a half hour until a sizeable gap in the clouds appeared & then targeted Lambda Aquarii to collimate...nice steady diffraction rings focusing down to a fairly evenly-illuminated Airy Disk...a rare situation for about as long as we could remember tbh! grin.gif  (see collimation image inset in the images below)


Naturally, by the time we had tracked down Neptune & started focusing in earnest the clouds swarmed back in - we sat there & we sat there rolleyes.gif  - although it is true to say that I walked off into the darker regions of the backyard to check the sky area from which all the clouds were coming - & let out a few expletives a few times! lol.gif


Marc's ephemeris predictions suggested the EQ spot would be on the C.M. about UT 09:42 but those clouds just kept on rolling through: by 11:45 we realised it was going to be touch & go for the spot to still be on the visible face...so despite losing about half of each avi to complete cloud cover as well as significant dimming in other sections of each 9 minute capture, we pulled the trigger.


It's not called "lucky imaging" for nothing & we were lucky to pull a 1000+ frames from each capture run at good quality...lamenting what "might have been" but capturing the bright EQ spot by the skin of our teeth as it started to disappear at the P limb...


Certainly if the clouds had not been there (& it was the seeing that was predicted to be average at best - the sky was meant to be devoid of any clouds!) we would not only have captured many more runs but no doubt been able to take r-g-b sequences as well as possibly some longer iR wavelength captures in addition - but we're grateful for what we got for sure...


Here are the 3 images which show the collimation image as well as another inset displaying each RAW stack...








Next is the animated sequence (reversing) of these 3 frames - remembering that the total timespan of the sequence was only just over 35 minutes - we got the spot by the skin of our teeth for sure!




Marc's ephemeris indicated that approximately 2 hours before our first capture (11:45) the bright spot would be at about L118° allowing for a drift rate of 2°+ per hour West: our rough measurement of the spot at L124° some 2 hours later is confirmation once again (as was our data from 17th) that he has done a very good job on this! waytogo.gif  




I'll post a short live-feed view later of Lambda Aquarii giving some further idea of how good the seeing was - but in the above images you can see that the first diffraction ring was pretty well complete & evenly illuminated...excellent seeing - pity about the clouds..!!! lol.gif


Here's the Registax6 sharpening regimen for these stacks for now - because I worked initially with 200% .pngs I employed a bit more than I use on capture scale stacks in R6 but they still turned out pretty nicely regardless... wink.gif




Here's the AS!3 "Quality estimation" graph for the UT 11:45 capture (the best) & as seen those clouds sure impacted upon the 9 minute capture..!


Btw, the "2129" frames shown is not from this capture but we did obtain a stack of 1950 frames of good quality surprisingly. smile.gif




Finally the FireCapture settings we used with the C14 fwiw...








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#2 Dunkstar



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Posted 21 October 2017 - 05:57 AM

Mo mate you must be yelling different expletives than I, as the clouds haven’t parted up here for weeks shocked.gif


Nicely executed as always, I’m fascinated by the surface features bow.gif

#3 AstroBobo



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Posted 21 October 2017 - 01:10 PM

I must say I am truly enjoying these images of Neptune and Uranus! This is really amazing, thank you!

#4 sfugardi



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Posted 21 October 2017 - 06:02 PM

Mo, excellent Neptune images! You are on a roll with this storm chasing. I see your gain continues to rise, now at 93%. Your raw stack quality is amazing, not to mention the entire set. Thanks for posting




#5 Kokatha man

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Posted 21 October 2017 - 07:54 PM

Thanks Duncan, Boris & Steve...& for the "Likes" posted also! smile.gif


A real "skin of the teeth" situation as far as timing was concerned - Dunk, maybe the swearing helped lol.gif but I usually mutter something like "that's life" - it was the steady seeing that made it especially frustrating...but such is life! wink.gif


Steve, this "storm chasing" could be construed as slightly obsessive rofl2.gif but "hey!" for us it's the only planet atm: we did stay up watching the idiot box hoping for the skies to clear that night in the hope of some Uranus possibilities, but the clouds only got worse...


You're doing extremely well with Neptune's elevation btw...don't forget that at home we get it up to about 63° & further North it's higher still.


Anyway, here's that little looping feed of L. Aquarii I said I'd post: don't forget that what you see is quite a bit better than what a continuous feed would display but the reality is that you are making your primary judgement upon a slightly more defocused image of the star (not a lot, however) & then focusing to confirm how well you have adjusted things - & it is how your eyes see a type of "integrated appraisal" that makes you decide when you have done the job properly...


Speaking of eyes (as well as planets to image) I have just received new prescription glasses (long overdue) & passed the Humphrey Field Test with no other discernible eye degeneration, so I've got that off my back for another year...I think my diabetes is back under control also, so hopefully I'm still alive & functioning next year for the planetary smorgasbord down here..! fingerscrossed.gif





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#6 Kokatha man

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Posted 22 October 2017 - 03:12 AM

...here's the WinJupos integration of the first 2 capture outcomes from this night - I've tended to leave WJ comps out of our Neptune images, not from the considerations that both Alex & myself have re Uranus...but more to do with the fact that I don't care/trust them as spot measurement images anywhere near as much as those single 9 minute stacks we capture...


The position of Triton is problematical imo - with 2 captures so close together as these were it is simple to "shift" one of the 2 Tritons WinJupos generates when they are so close together to the mid-point between each one...more stack integrations...& uneven timespans between stacks/captures makes this artificial re-positioning much more prone to errors...


In this instance it wasn't an issue (besides the fact that you need to shift 1 Triton's position! lol.gif) but it was the outcome for the disk I was interested in presenting here - so I've overlooked that particular reservation! wink.gif



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#7 CPellier



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Posted 25 October 2017 - 04:06 PM

Superb Neptune work Daryl, experience is really showing here...

#8 Kokatha man

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Posted 25 October 2017 - 06:40 PM

Thanks Christophe - nothing much else to image being honest wink.gif ...then again, with the return of clouds & jet-streams there's nothing at all to image atm! lol.gif

#9 Kokatha man

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Posted 27 October 2017 - 06:33 PM

Thanks for all the additional "Likes" posted since earlier - appreciated! smile.gif


With the clouds etc we're still looking several days ahead for our next imaging chances atm... frown.gif


Still half-asleep, but if this current bright spot continues it will start to approach the 42 days we managed to determine as the earlier feature's minimum lifetime...making previously-thought ideas about their longevity at these latitudes more uncertain...hmm.gif


EDIT: Whilst I'm editing my recent posts (to Kevin) I should edit this one & note that this most recent EQ feature's progress on Neptune has been almost solely from the contribution of AA'ers - keep up the good work folks! :waytogo:

Edited by Kokatha man, 27 October 2017 - 11:30 PM.

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#10 Planethunter80


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Posted 28 October 2017 - 09:21 AM

I look at it like this. Using a C14 to obtain clear(and detailed)views of Neptune(while also capturing Triton)is an amazing accomplishment.smile.gif 


I love viewing this part of the forum and seeing the amazing images you guys have spent so much time to capture.

Thank You for helping keep my fire lit for astronomy.bow.gif 

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