NGC 6905 also known as the Blue Flash Nebula, is a planetary nebula in the constellation Delphinus.
It is very small: its internal shell has angular dimensions 47"×34” and roughly conical extensions, with ansae-type formations along the major axis.
The central star is a white dwarf with an estimated surface temperature of 150.000 K. The distance of the nebula, as with most planetary nebulae, is not well determined and estimates range between 1.7 and 2.6 kpc. (Text adapted from Wikipedia)
Being so small, this image is a strong crop of the original frame.
Optic GSO RC12 Truss - Aperture 304mm, focal lenght 2432mm, f/8
Mount 10Micron GM2000 HPSII
Camera Moravian G3-16200 with external filter wheel 7 positions
Filters Astrodon Gen2 E-Serie Tru-Balance 50mm unmounted LRGB
Guiding system OAG Moravian M68 with guide camera Moravian G1-0301
Exposure details L 101x60" bin2 -20C
R 40x60" bin2 -20C
G 40x60" bin2 -20C
B 40x60" bin2 -20C
Total integration 3h41'
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5
Location Promiod (Aosta Valley, Italy), own remote observatory
Date 29/30 August 2021