Chasing a Supernova in NGC 7331: Nights 1–4 in Middle Tennessee
✨ NGC 7331 with Supernova 2025rbs ✨
Forty million years ago, a star exploded in a distant galaxy. This August, its light finally reached my telescope in Tennessee. It didn’t happen in one night, or even two. It took four clear nights, 287 exposures, and the patience to sift out the best 260 frames — nearly 22 hours of captured light — to reveal the galaxy and its supernova side by side.
That’s what astrophotography is: patience, dedication, and freezing history in light.
Using my 8” Celestron EdgeHD at native f/10 (2032 mm), ZWO ASI678MC camera, and Optolong L-Pro filter on a SkyWatcher EQ6-R, I wrestled with WiFi failures, muggy Tennessee humidity, and even ice crystals forming inside my camera. Each night added new frustrations, new fixes, and more hours of starlight collected. And once imaging started, I always let the rig hum along while I went inside, checked on my family, or slept, trusting the logs to tell the story in the morning.
Here’s how it all came together.
NGC 7331 with Supernova 2025rbs
Night 1 (Aug 15–16): The Struggle with WiFi
Humidity at 98%, mosquitoes swarming, and WiFi dropping nearly every attempt at plate solving. By the tenth drop I was ready to pack it up. But persistence won. I logged my EAF focus at ~52879 steps, refocused the guide cam, and by 11:35 PM the first exposure was underway. 50 subs later, I programmed the sequence, came inside, fed the dog, and let ASIAIR run all night before the auto-shutdown in the morning.
Tip from the Ledge: Log your focus positions for every optical train. Out-of-focus SCTs don’t show donuts. They show nothing.
First Exposures Coming in and the Supernova was Easily Seen!
Night 2 (Aug 16–17): Ethernet to the Rescue
WiFi was out, Cat 6 was in. I pulled a 100′ Ethernet cable from the garage to the ASIAIR, set a static IP, and suddenly had a rock-solid connection. I was easily able to run everything inside on my computer or my phone in the comfort of no bugs! But humidity struck again: stars turned into eggs until I cleaned the corrector plate and filter. At first, I was frustrated because it appeared I could not get into focus. Then I decided to go back out and check the lenses, which were ultimately the culprit! Once clear, guiding settled, and I scheduled the capture of 70 subs over 5.8 hours. I even caught a movie with my family while the mount ticked away outside.
Tip from the Ledge: Clean your optics nightly in humid climates. One thin film is enough to ruin subs.
Capturing NGC 7331
Night 3 (Aug 17–18): Ice in the Camera
The session almost ended before it began. My first flats revealed ice crystals from cooling the ASI293MC Pro in the muggy air. I cycled the cooler, cleared the frost, and started again. Ice in my camera during the summer months has been quite the problem. I have figured out an easy way to detect them while capturing flats. Look at the histogram… If the histogram is spread around that is a clue there is ice scattering the light. If you look closely, you will also notice tiny colored specs on the image.
Once I got the ice cleared up, the logs show 90 exposures captured, though guiding faltered briefly after midnight. By dawn, 7.5 more hours of data were secured.
Tip from the Ledge: Always inspect your flats. A frosted sensor will destroy your whole nights capture unless you catch it in time.
Ice on Camera Sensor
No Ice on Camera Sensor
Night 4 (Aug 18–19): Supernova and Planets
Back out again, more frost on the flats. Warming and re-cooling the camera fixed it, and Vega provided provided me an opportunity to reverify my collimation. From there, the ASIAIR guided 77 exposures through a steady temperature drop from 79.8 → 71.2°F. At 4:51 AM I stopped the run manually, swung over, and grabbed planetary videos of Venus and Jupiter in excellent seeing before sunrise.
As a result of all the humidity issues and icing, I ordered ZWO Desiccant Tabs and an Anti-Dew Heater Strip that morning—permanent fixes for the humidity wars. I’ll provide an update later with how to install them and what difference it makes!
Tip from the Ledge: If your flats frost, don’t panic. Warm, cool, repeat—and invest in desiccant and heaters.
Collimation Verification
Quick Snap of Jupiter
Results & Reflections
Lights Captured: 287 × 300 s
Lights Used: 260 (quality-culled)
Total Integration: 21 h 40 m
Calibration: Aug 17 + Aug 18 Vega Collimation and flats/flat darks
This dataset crushed my original 10–15 hour goal. Each obstacle—WiFi, film, frost—was solved one night at a time. The supernova, shining near NGC 7331’s core, feels like a reward not just for the photons captured, but for the persistence behind them.
Final NGC 7331 Stacked
For Newcomers
Astrophotography isn’t about perfect nights—it’s about stacking imperfect ones. Out of 287 frames, 260 survived. Out of four muggy nights, nearly a full day’s worth of integration emerged. That’s how you freeze history in light.
From the Nocturnal Ledge: Patience is the bridge between frustration and starlight.