The Andromeda Galaxy is one of those celestial targets that shines beautifully at nearly any focal length. Its vast expanse, combined with faint dark dust lanes and surrounding H-alpha nebulosity, makes it an ideal subject for both beginner and experienced astrophotographers.
In the fall of 2024, I dedicated an impressive 100 hours to capturing this galaxy using both my main telescope and a piggy-back lens at Starfront Remote Observatories. You can explore the deeper version of this image here.
Capturing Hydrogen and Oxygen Emissions
As with the deeper version, my goal for this widefield image was to highlight the surrounding hydrogen gas clouds and the newly discovered, extremely faint OIII arc. This was made possible by using dual-band narrowband filters, which allow the simultaneous capture of H-alpha (at around 656nm) and ionized oxygen (OIII, at around 500nm) emissions with a one-shot color camera.
While these filters are incredibly effective for capturing both wavelengths in a single image, they come with a trade-off: the sensitivity and detail achievable with a one-shot color camera cannot match the performance of a dedicated monochrome setup. Despite this limitation, I’m thrilled with the level of detail resolved using this equipment.
Combining Broadband and Narrowband Data
In addition to the narrowband data, I also captured broadband images, which revealed remarkable detail in the surrounding dark dust. To illustrate the impact of combining the two datasets, I’ve included a comparison slider below. This allows you to explore the difference between the pure broadband dust data and the enhanced image with added H-alpha and OIII emissions.
Can you spot the faint OIII arc in the final image?
Technical Details
Frames:
- Altair Ha Oiii DualBand 6nm CERTIFIED CMOS Filter 2″: 153×1200″ (51h)
- Altair Ha Oiii DualBand 6nm CERTIFIED CMOS Filter 2″: 152×600″ (25h 20′)
- OGMA UV/IR Cut 2″: 303×180″ (15h 9′)
- OGMA UV/IR Cut 2″: 79×300″ (6h 35′)
Total Integration: 98h 4′
Equipment:
- Samyang 135mm at f/3.2
- OGMA AP26CC camera
- ZWO AM5 (piggy backed)
You can find this image also posted on my astrobin profile.
Sky Plot
Feel free to explore the region around the Andromeda Galaxy using this interactive sky plot built by by Aladine Lite.