My take on the Triangulum Galaxy, Messier 33 or NGC 598. This has been a real labor of love. After a couple editing attempts in 2020 I never achieved a result I was happy with. Revisiting the project in 2021, with more data and post-processing knowledge, I’m finally happy to share my results.

The Triangulum Galaxy is a spiral galaxy located 2.73 million light-years from Earth in the Triangulum constellation, and is the third-largest member of the Local Group of galaxies behind Andromeda and our own Milky Way. The Triangulum Galaxy is some 60,000 light years in diameter. With very little sky pollution and good vision, the Triangulum Galaxy is visible to the naked eye. With binoculars and decently dark skies much more detail, including some dust lanes, begins to resolve.

Editing Details
Color data was captured with the 2600MC and Esprit 120ED (2020) and Esprit 80ED (2021). Luminance data was captured with the 2600MM, Astronomik UV/IR L2, and my new Takahashi FSQ-106EDX4. Hydrogen-alpha comes from combining monochrome data captured with the 2600MM, Esprit 120ED, and Astronomik Hα 12nm filter (2021), with red channel data captured with the 2600MC, Esprit 120ED, and Radian Triad Ultra filter (2020). Post-processing was handled in PixInsight and Adobe Photoshop. Color data was combined, cleaned up, and calibrated, and Hydrogen-alpha data was applied to accent nebulous regions. Monochrome data was processed separately (cleaned up, deconvolution, some mild star deemphasis, adjustments to bring out structure, etcetera). After combining luminance and color data stars were separated, some additional adjustments were made, and the results were sent to Photoshop for final post-processing. In Photoshop I employed J-P Metsavainio’s tone-mapping routine; processed small fuzzies background IFN (and maybe a galactic stellar stream?) separately; employed additional measures to accent detail in the galaxy and fainter signal; then recombining stars.

Total Integration Time
- 23 hours 12 minutes

Luminance Data
- 2021-10-29, 2021-11-04 - Bortle 3
| 120x160s Astronomik UV/IR L2
| ASI2600MM, FSQ-106EDX4, CEM-40EC
Color Data
- 2020-10-20, 2020-10-21 - Bortle 8
| 313x60s No Filter
| ASI2600MC, Esprit 120ED, CEM-70g
- 2021-09-26 - Bortle 4
| 63x180s No Filter
| ASI2600MC, Esprit 80ED, CEM-40EC
Hydrogen-alpha and Oxygen III
- 2020-12-03, 2020-12-04 - Bortle 8
| 63x300s Radian Triad Ultra 
| ASI2600MC, Esprit 120ED, CEM-70g
- 2021-09-21 - Bortle 8
| 43x300s Astronomik 12nm Hα
| ASI2600MM, Esprit 120ED, CEM-70g

Subject imaged at Salt Lake City, Utah, Bortle 8; Antelope Island State Park, Utah, Bortle 4; and in Skull Valley, Utah, Bortle 3; in the United States; in 2020 and 2021.