Heart Nebula (IC 1805) - SHO

Emission nebula in Cassiopeia captured with narrowband SHO technique

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Deep Space Capture

Technical Specifications

Resolution: 6000x4000 (2x drizzle upscaled)

Integration: 331 subexposures: 122 Ha + 111 OIII + 98 SII, 300s each

Captured: Captured over approximately one month

Equipment: Redcat71 refractor (350mm) with ZWO ASI2600MM Pro camera on Advanced VX mount

Location: Backyard location, Bortle 7 light pollution zone

Processing Workflow

Total integration time: ~19 hours across Ha, OIII, and SII filters

ZWO 7nm narrowband filters (Ha, SII, OIII) with 5-position filter wheel

Every sub-exposure dithered by 10 pixels for improved noise reduction

Drizzle integration at 2x scale for enhanced resolution

Guided using ZWO 30mm mini guide scope with ASI290MM mini camera

Controlled via ZWO ASIAir Plus with Electronic Auto Focuser

Scientific Context

The Heart Nebula (IC 1805) is located approximately 7,500 light years away from Earth in the Perseus Arm of the Galaxy in the constellation Cassiopeia. This emission nebula showcases glowing ionized hydrogen gas and darker dust lanes, creating its distinctive heart-like shape.

The nebula's intense red output and morphology are driven by radiation from a small group of stars near its center. This open cluster, known as Collinder 26 or Melotte 15, contains several bright stars nearly 50 times the mass of our Sun, along with many dimmer stars that are only a fraction of the Sun's mass.

This image was captured using the SHO (Sulfur-Hydrogen-Oxygen) narrowband technique, which reveals the rich blue and orange colors from ionized oxygen and sulfur gases. The narrowband approach allows for detailed imaging even from light-polluted locations by filtering out most artificial light sources while capturing the specific wavelengths emitted by these ionized gases.

The Heart Nebula spans almost 2 degrees in the sky, covering an area four times the diameter of the full moon. Its shape is sculpted by powerful stellar winds from the hot, massive stars at its core, creating the intricate structures and cavities visible in this image.