The Needle Galaxy in LHaRGB (Coma Berenices)

Planewave CDK12.5; AP 1100GTO Mount
QHY600M, - Antlia Pro Broadband and 3.5 nm Ha Filters
L: (34 x 180s, Bin 1, Gain 26)
H: (17 x 720s Bin 1, Gain 26)
R,G,B: (26,30,31 x 210s, Bin 1, Gain 26)
Total integration time = 10.1 hrs (Apr 26,27, 2025) Vancouver Island, BC, Canada
The bulge of a galaxy represents the result of the complex merging of the gravitational fields imposed by different geometries. In the middle of the galaxy lies a black hole exerting a spherical field pulling towards it.
The toroidal galactic disc as a whole imposes a field that follows a radial geometetry. However, this field is radially periodic in strength in both radial and angular directions due to the mass concentrations within the spiral arms. Away from the galactic centre, this keeps orbiting stars fairly tight within the spiral disc.
Within the donut hole of the disc, the attachment of the arms to form a linear gravitational field that creates a bar of material.
The superposition of these gravity fields near the black hole creates a complex orbit of the stars near the centre that we see as a bulge of foggy brightness.

Recently, I presented to my local (Victoria, BC) chapter of the RASC a description of spiral galaxies based on thermodynamics and fluid mechanics. This dispenses with a lot of the magical unicorns often used to describe how they work and replaces them with explanations that are more grounded in science. I have posted this presentation in two youtube videos - Part A and Part B, or alternatively, they can be viewed at APRealSpace.com.