NGC 7497, etc.
9 hours ago
- NGC 7497 is a spiral galaxy, but the nebula in the image is actually closer than the galaxy.
- The nebula is an Integrated Flux Nebula (IFN), located far from the Milky Way and lacking a central star; it is illuminated by the combined light of the Milky Way.
- The IFN has an unusually low surface brightness, with the brightest region at 26th mag/arcsec².
- Total exposure time was 28 minutes (56 × 30 seconds), with 25 minutes used in the stack.
- Equipment: C9.25 telescope (230mm, f/10, fl=2300mm) with 0.63 Starizona reducer, and IMX533 camera (16mm diagonal, square, color).
- Processing steps included calibration (dark + flat), debayer, stacking (average with outlier rejection), white balance, background subtraction, asinh stretch, rotation, crop, and tone curve.
- Observation was challenging due to a poor southern horizon, as this part of the sky rises only about an hour before sunrise.