April - May 2014
This project (along with the first part of the Virgo Cluster and M51 in
H alpha) was the first project after the long delays due to
is a bright, large Globular cluster in Serpens
Caput. It lies just two degrees north of the equator. It
sports a collection of red giants which the image
below clearly shows.
This is a NB4Stars
project. Instead of using LRGB filters I use two Stromgren
filters (V and Y) and a special 20nm Hydrogen Alpha filter.
click for a 1/2 frame image
The image below is 1/2 frame of the camera. The markings on
the stars are the B-V values. These can be used to determine
whither I got the colors correct.
Since this is outside the plane of the Milky Way many dim galaxies were
also captured in the picture. This
links to a second annotated image that shows all of the galaxies
captured in the frame.
The images were processed with PixInsight.
|16 x 900
|16 x 900
|Ha20 (20nm H alpha)
|13 x 900
The color correction for this image was based on a G2V
Since that led to the Blue in bright stars being blown out I
did an additional step of limiting the Blue channel
B = min ( G * 1.5, B)
This limited the amount of B in bright stars to a reasonable level.
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