Jupiter 4 May 2018 - at last some fair seeing, but I was late getting to it....!!

[geoflewis]

After 2 consecutive failed nights on Jupiter this week due to dreadful seeing, despite clear skies and having checked the sky at about 23:00 last night to see total cloud cover I'd given up expecting any imaging opportunity. As I headed to bed around midnight, I looked out to unexpectedly see stars, so I quickly aborted ideas of sleep and headed out to the obs. The obs was warm from the day, but with Jupiter already heading towards transit there was no time to cool the scope, so I just had to get cracking. To my surprise seeing at last was reasonable and my first few capture runs trying sort focus saw the GRS just exiting right - damn.!! It took me several attempts to get focus sorted, no doubt due to the scope not being acclimatised, but I eventually captured a few RRR-GGG-BBB runs and a couple of IR. Image quality is superior with the IR filter, so I've done a quick process on one of those as a taster...

 

This is 30% of 5000 frames with my ZWO ASI120MM plus Astronomik IR PRO 742 filter, stacked in AS3!, with wavelets applied in Registax6, but no other processing. There is some reasonable detail showing, which bodes well that some of the RGB runs will be ok, though I'm not expecting them to be as sharp as the IR. We had a beautiful sunny day out at the north Norfolk coast today with our 19 year old granddaughter who is visiting for the BH week end, so processing last nights run had to wait. Hopefully I can get to some of those in the next few days, but I just can't pass up this lovely weather while we have it.

Tonight the obs has already been open cooling down the past 3 hours and I'll be heading down there soon, hoping that the seeing is again as good as last night. If seeing is good then I may also try some RGB runs with my old Imaging Source DBK colour camera as a comparison to the mono R-G-B with the ASI120.

Anyway I hope you enjoy my first passable Jupiter this year, albeit only a mono image.

Cheers, Geof

[MarsG76]

Some good detail is punching through there.... I find that my Skyris 618C is a good performer comparing to the DMK21au618 through RGB filters so I'm curius how your OSC DBK cam compers to the ASI mono

 

[tooth_dr]

Very nice. 3 nights now I’ve tried Jupiter and it’s been shitty. 

[geoflewis]

10 hours ago, MarsG76 said:

Some good detail is punching through there.... I find that my Skyris 618C is a good performer comparing to the DMK21au618 through RGB filters so I'm curius how your OSC DBK cam compers to the ASI mono

Thanks. I did get some runs with both the ASI120MM and DKK21AU04.AS last night though the seeing started to deteriotate after I switched to the DBK - either that or the reduced sensitivity of the much older DBK camera was fooling me. I'll try to find time to process the data today and post a comparison, but I hate to be stuck indoors in front of my laptop during this excellent weather.

I also am having issues with my laptop clock going wrong, which is a nightmare for planetary imaging as I need accurate timestamps to derotate the AVI stacks in WinJupos to improve SNR, so I'm going to have to work through each AVI against WinJupos ephemirides to check timestamp accuracy...!!

[geoflewis]

10 hours ago, tooth_dr said:

Very nice. 3 nights now I’ve tried Jupiter and it’s been shitty. 

Thanks, it's definitely a waiting game....!! The last 2 nights here have been pretty good, but the previous 2 nights were dreadful. With Jupiter at such a low altitude it's difficult to capture good data even when the seeing seems reasonable, but keep at it, your time will come....

[geoflewis]

Well here is the result of my first set from night of 4th/5th May taken during the same session as the previously posted mono IR image, but resized for display.

 

It comprised best 30% 4000 frames from each of 3x3 RGB runs (i.e. RRR-GGG-BBB), stacked in AS3!, wavelets in Registax6, derotated in WinJupos and post processed in PS. It was a lot of effort for a somewhat underwhelming image , but I think that's going to be the story with the 3 main planets (Jupiter, Saturn & Mars) from the UK this year. I'll see what the other runs turn out like and will post last night's mono v colout camera comparisons on a seperate thread once I get around to processing them.

[geoflewis]

...and the first set from the night with same capture sequence (4000 frames each RRR-GGG-BBB), but using best only 15% and with much softer processing...

The scope had no time to acclimatise, plus I think I also missed best focus, but I was in a hurry as GRS was just exiting right....