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Hi all, So far we have 14 in the Group, 15 including Avani Soares, who has committed but hasn't actually joined yet. I really would like to get to twice this and I have been making contact with various imagers whose images are clearly of high quality. Could I also ask you to make contact with anyone you know who has the equipment and technique required to join the group. Do we want to target anyone who is not an AstroBin user? I originally proposed that we focus on imaging around the GRS, however, I think it would be better to just image Jupiter in the 2-3 weeks around opposition whenever you can and the seeing is good enough. We can then use these images to create a planetary map for each period. It would be beneficial to coordinate the image parameters such as size, but I haven't got my head around how to do that. Any suggestions? We need to think about image size, colour consistency, histogram levels, the presence of moon shadows etc I compared two images I took of Jupiter 5 days apart on the 29th April and 4th May. The latter is of very poor quality due to the seeing, but good enough to see the movement in the Equatorial Belt. I uploaded this to my Staging Area but can't seem to share it with you without going "public" and the quality of the 2nd image doesn't warrant that. If you are interested here is a DropBox link to it. https://www.dropbox.com/s/1th5dcu9qu22ax4/Atmospheric%20movement%20in%20Jupiter%20over%205%20days%2029.4.17%20and%204.5.17.png?dl=0 In any case I measured the movement of the features in the Equatorial Belt, which as you know is by far the fastest moving region. I calculated that they were moving at ~ 0.1 arc seconds per hour at the centre of the planet. So in 10 hours, the approximate rotational period of Jupiter they will have moved ~ 1 arc second. Therefore for the sort of resolution we would expect in a movie, we can consider the planet's atmosphere fixed over one rotation, with a possible movement/ smear of features of no more than 2-3%. So ideally, we would try and create a planetary map for each rotation of the planet. However, this may be impractical and perhaps creating one map for each 24 Earth day would make more sense, allowing some overlap between imagers, but recognising that this means that some features in the Equatorial Belt would have moved 2-3 arc seconds in this time. This may result in some misalignment of features from one imager to another and some inaccuracy in the final planetary map, but shouldn't impact the final result too much. Does anyone disagree that we should target the generation of a planetary map for each 24 hour Earth day? I also suggest each day should commence at UT 00:00. Thoughts or comments welcome. Cheers, Niall |
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Agree with all your remarks, Niall. Will try to get back to imaging tonight. It will - if conditions allow that is... - begin somewhere near 05/14 01:00 to 02:00 UT. GRS will be transiting at the time. Will see... Clear skies for us all! Almir |
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Thanks Almir  |
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Here in São Paulo the sky is clear but the seeing can say that it is -1  Good luck out there. |
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No luck here in Maringa either... |
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Same! The seeing here has been poor for days. Winter is definitely the worst season for seeing here. People say to me "oh it will be great on those lovely clear winter nights", but I look up and see the stars twinkling madly and know it's not even worth having a look.  |
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| All this happens here too, Niall ... people talk, what a beautiful and starry night, but seeing is bad, so it was here this weekend, the winter is very bad for planetary astrophotography ... |
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Tem sido semanas desde que eu fui capaz de conseguir algo aceitável! Desde que eu estou no extremo sul do Brasil, acredito que as minhas condições são ainda piores do que aqueles que estão mais ao norte. Eu não tenho grandes esperanças para Saturno este ano como eu não obter bons resultados no ano passado. |
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Tudo o que você pode fazer Avani é estar disponível quando essas raras noites de excelente ver vêm junt  |
