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NGC 2903 and Satellite Galaxy UGC 5086, Leo

astrophotography ccd CMOS dslr dso imaging Orion refractor
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#1 rekokich

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Posted 28 May 2020 - 03:54 PM

NGC 2903 and Satellite Galaxy UGC 5086, Leo

NGC 2903 is a barred spiral galaxy in Leo, discovered by William Herschel in 1784. Although it is fairly large and bright, easily seen in binoculars, it escaped Messier's attention. Except for a dwarf elliptical galaxy UGC 5086 at the distance around 1.86 million ly, it has no close companions to disrupt its delicate spiral arm structure. On the large scale, NGC 2903 is a member of the Virgo Supercluster which includes the Milky Way and Andromeda galaxies. The inner spiral arms are beaded with numerous light blue OB associations composed of billions of young, very hot stars, indicating a high rate of new star formation. Immediately E of the nucleus is located a large, bright star cloud separately catalogued as NGC 2905. The galaxy's nucleus is bright in all bands, from radio waves to X-rays, suggesting the presence of a central supermassive black hole with an accretion disk and polar jets.

Limiting magnitude on the attached image is around 19. The most remote identifiable object is galaxy SDSS J093305.61+214041.5, lying at the comoving = proper distance of 1.814 billion light years, and receding at 39,119 km/sec.

Image details:
-TSAPO100Q astrograph, Sigma APO 1.4x tele-extender (100 x 812 mm)
-iEQ30pro mount, Orion 60mm f/4 SSAGpro autoguider
-Canon T3i modified camera, Astronomik L3 filter
-24 x 300 sec subs, ISO 1600, 30 dark and 30 bias frames, 2x drizzle, 25% crop
-Software: PHD2, DSS, reprocessed with XnView and StarTools

 

Thank you for looking.

 

 

z1.jpg


Edited by rekokich, 28 May 2020 - 03:57 PM.

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#2 rekokich

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Posted 28 May 2020 - 03:55 PM

z0.jpg

 

z2A.jpg


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#3 sunnyday

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Posted 28 May 2020 - 03:58 PM

nice details and colors .

thanks .



#4 MikiSJ

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Posted 28 May 2020 - 04:00 PM

Very excellent! Wow factor of 9.9/10.0!



#5 Astroman007

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Posted 28 May 2020 - 04:11 PM

Very nice image, great backstory. Thank you for sharing all!



#6 alvarete

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Posted 28 May 2020 - 04:59 PM

Thank you very much Rek.

#7 Chris_Mammendorf

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Posted 28 May 2020 - 05:10 PM

Thanks for showing - phantastic :-)



#8 Steve OK

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Posted 29 May 2020 - 06:57 AM

Great color and detail!

 

Steve



#9 Readerp

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Posted 29 May 2020 - 07:55 AM

Nice job! 

 

Have you done a comparison of the 2x drizzle to not using it?

Seems like you may have. I would like to hear your findings.

 

Cheers

Pete



#10 Starman27

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Posted 29 May 2020 - 11:14 AM

Great image.



#11 rekokich

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Posted 29 May 2020 - 11:13 PM

Thank you all for encouraging comments.

 

For the same image with a Ha stack added, see this link:

https://www.cloudyni...nd-mama-clouds/

 

Pete,

 

Unfortunately, I never made a study of 2x drizzle. I just took it for granted that "it might be of some minimal benefit." I normally take my subs with a Canon T3i APS-C sensor at 5184x3456 resolution. My TSapo100q telescope has only 580mm fl. For smaller objects, I have to use a Sigma apo 1.4x tele-extender (100x812mm), and to crop images 50% linear = 25% area, or even 33% linear = 11% area. In those cases, I use 2x or 3x drizzle, and crop images in DSS before stacking to bring the result back to 5184x3456 resolution.

 

Any differences between (stacking then cropping) and (cropping with drizzle and then stacking) would not be visible on my 1600x900 monitor unless I zoomed in 300%. And, they would not be visible on large prints or CN posts. So, I never paid it much attention.

 

But, now you have made me curious. The problem is that I usually keep only the final stacks and discard all the subs (scientific sacrilege) when done with processing. I should be able to find some subs on the camera's SD cards. I will look into the matter, and post the results eventually.

 

Rudy


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