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Nice southern cluster NGC 2477 with EdgeHD11 Sloan colors 1.7" fwhm

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#1 freestar8n

freestar8n

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Posted 12 February 2019 - 04:30 AM

This is a nice southern open cluster, NGC 2477 taken with Sloan i' r' g' filters at f/7 with ASI1600. fwhm's in the stack are about 1.7" with a total of just under 1 hour exposure. 2m x 9 in each filter.

 

No processing or cropping other than levels, gradient removal, and slight color adjustment. Colors calibrated with foreground stars that have APASS sloan magnitudes in UCAC4.

 

You can see faint background galaxies throughout - and since no sharpening or smoothing has been applied the stars are more easily distinguished from smudgy galaxies.

 

At lower left is a side-on galaxy, PGC 22009

 

You can tell that the brighter stars are blue - but there are additional very bright orange stars. They are red giant branch (RGB) stars. This is a medium age cluster only about 1 billion years old.

 

A nice paper with details is:
https://www.aanda.or.../aa0151-04.html

 

You can see how the distribution of stars matches isochrones for 1 Gy age.

 

 

ngc2477__irg_xgrads.jpg

 

Astrobin link:

 

get.jpg?insecure

 

 

Frank


Edited by freestar8n, 12 February 2019 - 04:32 AM.

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