NGC 6210 is a planetary nebula found in the constellation Hercules.
It is located between 4000 and 6500 AL of the earth.
It is difficult to exactly locate a planetary nebula.The problem is that it is impossible to tell the difference between an NP which is 4000 AL of another which is 8000AL but which is 2x more luminous !
The Turtle is a very bright NP (mg area: 9) but small, the heart is almost 18 ''. It takes tight sampling to differentiate the details between them.
It is perfect for short exposures
I used my 2x barlow with the draw, a ratio of 2.7x, for the 300mm F4 is perfect!
As usual, I added several nights. I started in April 2018 but the result I did not like .. I added a few nights these days.
I totaled 12500x500ms in 2018, and 50000x500ms this year.
For extensions, I used 3sx2200 poses.
In the group of short exposures I posted a description of the treatment I used to get this picture.
In fact I used several nights of the same expo to bring out the max of details that my setup and the seeing allowed me to do.
I used SIRIL for stacking, revealing details and improving the background.
After that I used cs for layer mixing and cosmetic tweaking.
It's a 2x drizzle ...
a crop of the center with a picture of the @HST to just check that certain details are present on my image:
then a montage to account for the apparent dimension of this planetary nebula with other known planetary nebulae:
TN300mm F4,Atlas (eq6), barlow 2x with draw (2,7 x) and ASI224MC
Edited by exaxe, 17 April 2019 - 03:38 PM.