Sh2-173

About image
This faint nebula in Cassiopeia constellation is also called "The Phantom of the Opera"; the name derives from its resemblance to a theatrical mask.
Physically this is a HII region with a diameter of 77 light years, located at about 2700 parsec (about 8800 light years) away.

Technical data
Optic            Tecnosky Apo Refractor LT 130 - 910mm f/7
Mount          10Micron GM2000 HPSII
Camera           Moravian G3-16200 with external filter wheel 7 positions
Filters        Baader RGB 50.8 unmounted
Guiding system      OAG Moravian M68 with guide camera Moravian G1-0301
Exposure details    Ha 20x1200" bin1 -20C
                                      R 14x300" bin1 -20C
                                      G 14x300" bin1 -20C
                                      B 18x300" bin1 -20C
Total integration    10.5h
Acquisition        Voyager, PHD2
Processing        Pixinsight 1.8, Photoshop CS5
SQM-L         20.68 (Moon in the sky)    
Location         Promiod (Aosta Valley, Italy), own remote observatory
Date            19/20 September 2018

© Roberto Marinoni 2019 - All rights reserved