Sh2-157 – Lobster Claw Nebula
Sh2-157, known as the Lobster Claw Nebula, is an extensive emission nebula located in the constellation Cassiopeia, near the border with Cepheus. It has an apparent angular size of approximately 90 arcminutes, while its integrated visual magnitude is not well defined because of its low surface brightness.
General information
- Constellation
- Cassiopeia
- Category
- Nebulae
- Date
- 6 July 2026
Capture
- Total time
- 5h 40min
- Subframes
- 300s (Ha: 28x, OIII: 24x, SII: 16x) bin1
- Gain / Offset
- 125 / 30
- Calibration
- 30 flat frames, 30 dark-flat frames and 40 library dark frames per sessió and filtre, without bias frames
Equipment
- Telescope
- TS102ED f/5.6
- Camera
- ASI294MM at -10ºC
- Filters
- Ha, OIII and SII Astronomik, 6 nm
- Mount
- Sky Watcher Wave 150i
- Guiding
- PHD2, Guide scope 60mm/f4 + ASI220MM + PegasusAstro UCH + PPBMicro
- Focuser
- ZWO EAF
- Filter wheel
- ZWO EFW 7pos
Processing and environment
- Processing
- Stacked and post-processed with PixInsight 1.9.4
- Acquisition
- NINA
- Location
- l'Ampolla
- Sky
- Bortle 4
Annual visibility
204 days per year above +30° at 00:00 UTC from 41° N, 1.5° E.