🌌 #8: Andromeda, Hercules and the Pleiades

Posted on by admin

On this particular night, I returned to some familiar celestial faces — the kind you never forget: M31 (Andromeda Galaxy), M13 (Hercules Cluster), and M45 (The Pleiades). The goal was simple: take what I had learned and apply it to targets I’d already photographed, this time aiming for better results. A deeper dive, longer exposures, and a growing understanding of the post-processing world.

🔭 A Night of Three Targets

M31 – Andromeda Galaxy
One of the first deep-sky objects my brother and I ever pointed a telescope at. Back then, it was a quick attempt with little planning. This time, I had a new camera — the Olympus E-510 — and wanted to keep the exposure length and ISO constant (60 seconds @ ISO400) while increasing total integration time. I managed to capture 75 minutes‘ worth of data. Sounds like a good idea, right?

Well
 focus. Always focus. I had used a homemade Bahtinov mask and was sure I had nailed it. But something shifted during the session — and the result? Blurry stars, no detail, just soft blobs of light. The majestic dust lanes of M31 were barely visible. Lesson learned: even the best plan fails without sharp focus. Always double-check.

M13 – Hercules Cluster
This target was a revisit from my earlier field trip — the one cut short by clouds. Tonight, the sky was clear and stable. I dedicated over an hour to M13, capturing 75 light frames and matching them with darks and bias frames. The goal was to enhance the outer star field without blowing out the bright core — not an easy task.

In the end, I created four versions of the image. Each one reflects a different processing strategy:

  • V0: A natural, slightly underexposed look
  • V1: More aggressive stretching with masked highlights
  • V2: Balanced curves, preserving faint structures
  • V3: Strong core dimming to reveal inner star detai

I’m still unsure which one I like best — feel free to share your favorite.

M45 – The Pleiades
Late in the evening, the Pleiades rose above the horizon. I had observed them many times before but never tried to photograph them. Due to the hour, I only managed 10 light frames. Despite the limited exposure, the result was promising: beautiful diffraction spikes on the brighter stars and even the first hints of interstellar nebulosity. Highlighting the gas without drowning in background noise was tricky, but it was the start of something worthwhile.

⚙ Technical Details

M13 Acquisition Setup

  • 75 x 60″ light frames
  • 15 x 60″ dark frames
  • 15 x bias frames
  • ISO 400
  • Olympus E-510 on SkyWatcher 150/750 PDS (unguided)

🧠 Key Lessons

A) Don’t try to image three objects in one night. You’ll spread yourself too thin, and the data will suffer. Even with perfect focus, I doubt M31 would’ve shown much detail with so little attention.

B) Focus. Then focus again. And maybe again after that. A small shift in the focuser can cost you an entire session. There’s nothing quite like the heartbreak of reviewing blurry subs.

C) Revisiting targets is not only worth it — it’s essential. You get to compare progress, experiment with new techniques, and deepen your understanding of each object. It’s not repetition; it’s refinement.

In the end, it wasn’t just about taking better pictures. It was about improving routines, discovering pitfalls, and learning how small details make a big difference. I walked away with more than three images — I walked away with insight.

Clear skies,
Chris