Ionized Halo of Andromeda galaxy (M31) - deepest image with O3 arc
400 hours of integration
Published by Imran Badr on Mar 1, 2026
This image shows the Andromeda Galaxy (M31) within an expansive field of ionized ha and o3 emission. The spiral structure is surrounded by faint, large-scale nebular filaments that extend far beyond the disk. Pink star-forming regions trace the arms while subtle blue-green tones reveal o3 emission interwoven through the halo.
Captured over many nights using deep narrowband and broadband integration, this image combines ha, s2, o3, and RGB data. Continuum subtractions were used to isolate emission structures, allowing faint ionized features around the galaxy to emerge. Careful dynamic range control preserved the bright core while maintaining delicate outer filaments.
I wanted to step beyond the iconic portrait of Andromeda and instead explore the interaction between galaxy and surrounding medium. To me, this image feels immersive and atmospheric, revealing that even a familiar neighbor exists within a vast and complex ionized landscape.
Equipment and Acquisition
Dates: Aug 2024 - Nov 2025
Telescopes:
Askar FRA 300 pro
Sharpstar 13028 HNT
Mounts:
2xZWO AM3 x2
Camera:
ZWO ASI2600MM Pro x2
ZWO ASI2600MC Pro
Filters:
Antlia 2.5nm S,H,O
Antlia 3nm Highspeed O3, and Ha
Exposures:
broadband: 4h52m
Ha: 215h35m (300s, 600s)
S2: 46h35m (300s, 600s)
O3: 132h50m (300s, 600s)
Total Integration: 400h
Software: PixInsight, Photoshop