IC1805 – Heart Nebula (SHO)
IC1805, known as the Heart Nebula, is an extensive emission-nebula complex in the constellation Cassiopeia. It has a visual magnitude of +6.50, an apparent size of 60 × 60 arcminutes and a physical diameter of about 200 light-years. It lies approximately 6,200 light-years from Earth. At its centre is the open cluster Melotte 15, whose young, massive stars emit intense ultraviolet radiation that makes the hydrogen gas glow and sculpts the nebula's intricate dust structures. In the SHO composition, also known as the Hubble palette, ionised sulphur (SII) is assigned to red, hydrogen-alpha (Ha) to green and ionised oxygen (OIII) to blue. The central cavity around Melotte 15 displays intense blue tones, while the dust pillars and outer edges of the heart take on golden and orange hues. These colours are representative and depend on the processing palette used.
General information
- Constellation
- Cassiopeia
- Category
- Nebulae
- Date
- 4 December 2023
- Capture sessions
- 13 Jan 2023 — Ha, OIII and RGB
3 Dec 2023 – 4 Dec 2023 — SII
Capture
- Total time
- 6h 40min
- Subframes
- 360s (Ha: 20x, OIII: 20x, SII: 17x) bin1; estrelles RGB: 60s (R: 20x, G: 20x, B: 18x) bin2
- Gain / Offset
- 125 / 30
- Calibration
- 30 flat frames, 30 dark-flat frames and 40 library dark frames, without bias frames
Equipment
- Telescope
- TS102 f/5.6 with corrector-flattener 0,8×
- Camera
- ZWO ASI294MM at -10 °C
- Filters
- Ha, OIII and SII Astronomik, 6 nm; R, G and B per a les estrelles
- Mount
- Sky-Watcher HEQ5 Pro with belt drive
- Guiding
- Not specified
- Focuser
- ZWO EAF
- Filter wheel
- ZWO EFW, 36 mm and 7 positions
Processing and environment
- Processing
- Stacked and post-processed with PixInsight 1.8.9
- Acquisition
- NINA + Cartes du Ciel
- Location
- l'Ampolla, Tarragona
- Sky
- Bortle 4