M33 – The Triangulum Galaxy (6 Hours of Integration!)

The Triangulum Galaxy (M33) is the third-largest member of our Local Group, after the Milky Way and Andromeda. At only 2.73 million light-years away, it’s close enough to show incredible detail in amateur images.

M33 Triangulum Galaxy

Equipment

  • Telescope: Orion 8″ 1000mm f/4.9 Newtonian reflector
  • Mount: Orion Atlas EQ-G
  • Imaging Camera: Canon T3i (full spectrum modification)
  • Guide Scope: Meade 800mm f/10 reduced to f/5 with Atik x.5 focal reducer
  • Guide Camera: Meade DSI Pro monochrome 16-bit

Capture Details

  • Integration: 120 x 180sec exposures (6 hours total!)
  • Captured: Across three nights in October 2025
  • Software: N.I.N.A 3.1 for capture, Siril 1.4.0 for stacking
  • Resolution: 4905 x 3223 pixels

About This Object

The Triangulum Galaxy is often overlooked in favor of its larger neighbor Andromeda, but M33 has a lot to offer:

  • 61,100 light-years in diameter
  • Shows beautiful spiral structure with many HII regions (star-forming nebulae)
  • Face-on orientation gives us a clear view of its spiral arms
  • The reddish blobs visible throughout are star-forming regions similar to our own Orion Nebula

This was a marathon project — 6 hours of integration over three nights. The extra exposure time really helps bring out the faint outer arms and the numerous HII regions scattered throughout the galaxy.

See more deep sky images in the gallery →

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