About image
IC 1805 (also known as the Heart Nebula or by the acronym W4) is a diffuse nebula associated with an open cluster, visible in the constellation Cassiopeia.
This is a very large HII region, whose distance is estimated at 7500 light years from us; its main characteristic is the presence of two large apparently empty areas of different sizes, which make the nebula similar to a "heart".
Inside there is a system of small, poorly concentrated open clusters, responsible for the ionization of the nebula: the most notable of these is Melotte 15, which contains some stars about 50 times more massive than the Sun.
Technical data
Optic TS Optics 76 EDPH - Aperture 76mm, focal lenght 342mm, f/4.5
Mount Skywatcher EQ6R
Camera ZWO ASI 294MM Pro with external filter wheel 7 positions
Filters Antlia 36mm RGB, Ha/OIII 3.5nm
Guiding system Artesky Ultraguide 32mm
Exposure details R 55x120" bin2 -25C
G 56x120" bin2 -15C
B 44x120" bin2 -15C
Ha 32x300" bin2 -15C
OIII 23x300" bin2 -15C
Gain 120
Total integration 9h45'
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5, NoiseXTerminator, StarXTerminator, BlurXTerminator
SQM-L 21.05
Location Promiod (Aosta Valley, Italy)
Date 7/8 October 2023