Sh2-101 — Tulip Nebula
Cygnus · Askar FRA400 · ToupTek ATR585M · Sky-Watcher AZ-EQ6 PRO · 2026-04-08
Acquisition
| Filter | Exposures | Sessions |
|---|---|---|
| H-alpha 6.5nm | 45 × 300s | 3 |
| SII 6.5nm | 67 × 300s | 3 |
| RGB Stars | 15 × 60s each | 1 |
Total integration: 10h 05m
Main Challenges
Waiting for a third session to add more OIII data. High stellar wind region required careful star management in PixInsight to preserve the nebula's fine edge structures.
Process Notes
The Tulip Nebula (Sh2-101) is an emission nebula in Cygnus, about 6,000 light-years away, shaped by the powerful stellar winds of the Wolf-Rayet star HDE 227018 at its heart. It sits in the same field as the microquasar Cygnus X-1 — one of the most studied black hole candidates in the galaxy.
Acquired over 3 nights (Apr 4–8, 2026) from a Bortle 3 site in Liguria, Italy.
The SHO Palette
In SHO, the sulphur (SII) traces the outer shock fronts where the stellar wind slams into the surrounding interstellar medium — rendering in red the sharp, sculpted edges of the "petals." The hydrogen (Hα) fills the bright core and broad ionised shell with green-gold tones, revealing the full extent of the nebula's structure. The oxygen (OIII) picks up the hotter, more energetically ionised gas closer to the central star, adding blue-teal depth and contrast in the inner regions.
Together the palette makes the turbulent interaction between star and nebula far more visually distinct than a pure narrowband or broadband image could.
Software
Stacked and processed in PixInsight. Acquisition managed with N.I.N.A., autofocus via ZWO EAF through the ToupTek AFW-M 8-position filter wheel.