M33, the Triangulum Galaxy — at 2.7 million light-years the third-largest member of our Local Group, and faintly visible to the naked eye from a truly dark site. The Hα layer in this HaLRGB blend makes its star-forming regions pop as red knots along the arms, including NGC 604, one of the largest known stellar nurseries anywhere. Four hours of short 15-second LRGB subs keep the core clean, with 80 minutes of 3nm Hα layered on top.

• Coordinates: RA 01h 33m 51s, Dec +30° 39′ 37″ (Triangulum)
• Optics: Askar 107PHQ
• Camera: ZWO ASI2600MM DUO
• Mount: Sky-Watcher Wave 150i
• Filters: Baader LRGB + UV/IR-cut (CMOS-optimized), 2 in; Antlia 3nm Hα, 2 in
• Integration: 5h 20m — L 1h (240 × 15″), R 1h (240 × 15″), G 1h (240 × 15″), B 1h (240 × 15″), Hα 1h 20m (16 × 300″)
• Published: 2025-08-21 — on AstroBin