About image

The image shows an area in the southern side of Cassiopeia constellation, where we can see four open clusters in the same frame.
In the center there is NGC 663, composed by a hundred of white stars and an estimated age of 20 million of years: its distance from Earth is 7900 light years.
On its left there is NGC 659, smaller in apparent dimension and less showy, at an estimated distance of 6300 light years.
On the right of NGC 663 we see NGC 654, composed by about sixty stars and characterized by the presence of one bright star on its side: it is located at a distance of 7800 light years.
Very near to NGC 654 there is the bluish nebula VdB6, but it is barely visible in this image obtained from my Bortle 8 sky.
But the more interesting cluster is, in my opinion, IC 166, visible in the upper right side of the frame. It is fainter than the other three and shows reddish stars, maybe due to the interstellar absorption.

Technical data
Optic         Tecnosky Apo refractor LT 130-910 with Riccardi reducer 0.75x (focal lenght 692mm, f/5.3)
Mount       Skywatcher EQ8
Camera                      Moravian G3-16200 with external filter wheel 7 positions
Filters                         Baader 50mm unmounted RGB  
Guiding system         Artesky Ultraguide 70mm 
Exposure details    R 42x120" bin1 -20C

         G 39x120" bin1 -20C
            B 42x120" bin1 -20C
Total integration       4h6'
Acquisition                Voyager, PHD2
Processing                Pixinsight 1.8, Photoshop CS5, NoiseXTerminator
SQM-L                       Bortle 8    
Location                    Rescaldina (Italy), home terrace
Date                          12/15 November 2023