Messier 33 (M 33) - Triangulum Galaxy

Introduction | Map | Find/Identify | Sketch | My Best Own Photos | My Own Observations | References || Appendix: My Own Photos

On this page I collect my observations of the Triangulum galaxy M 33 (NGC 598) in the constellation Triangulum, including the enclosed HII region NGC 604.

Introduction

The Triangulum Galaxy M 33 in constellation Triangulum is the third largest galaxy in the "local group," which also contains our Milky Way and the Andromeda Galaxy M 31. It is considered to be the most distant celestial object visible to the naked eye. I had problems even with my small refractor to catch just a glow at all. According to Stoyan, the problem with this DSO is that the exit pupil is too low. According to this author, the best magnification for a 3" telescope is 12 x. Thus, for my PS 72/432 it would be even less (10 to 11 x...). Such low magnifications also require a very dark sky so that there is enough contrast to the sky background... In France, I was able to catch at least a faint glow in autumn 2018...

M 33 (NGC 598)		NGC 604 (H II Region)
Size: 30' x 20' / 70.8 x 41.7(Stoyan/Wikipedia) Distance: 2.76 million light years (Wikipedia) Rating: *** (Stoyan)		Size: 2' (Wikipedia) Distance: 2.76 million light years (Wikipedia) Rating: ---

H II Regions

The galaxy M 33 includes a number of H II regions (see below), which correspond to galactic emission nebulae, the brightest of which is NGC 604 that I discovered on an eVscope photo in February 2020 (later, I found all the major H II regions). For more information on H II regions in M 33, see page Vaonis Vespera - H II Regions. Only the evaluation by nova.astrometry.net is shown here (M 33 , Oct 30, 2022):

H II regions in M 33: IC 131, IC 132, IC 133, (IC 134*,) IC 135, IC 136, IC 137, IC 139, IC 140, IC 142, IC 143, NGC 588, NGC 592, NGC 595, NGC 604
*) IC 134 is a star

Map

M 33 (Triangulum Galaxy) in the constellation Triangulum; the Andromeda Galaxy M 31 is also marked, as well as several open star clusters (Image Courtesy of SkySafari Astronomy, www.simulationcurriculum.com)

Find/Identify

Find: I found the Triangulum Galaxy M 33 by moving down from the Andromeda Galaxy M 31 to the bright star Mirach - and then moved about the same distance down in the same direction. See map below:

Identify: Once you have found M 33, you can be sure that it is M 33. (Image Courtesy of SkySafari Astronomy, www.simulationcurriculum.com)

Sketch

Note: I only have the author's permission to link to the sketch.

My Best Own Photos

eVscope


M 33 - Nov 14, 2020	M 33 - Nov 14, 2020	M 33 - Nov 14, 2020

M 33 - Nov 14, 2020, processed	M 33 - Nov 14, 2020, processed	M 33 - Nov 14, 2020, processed

M 33 - Jan 24, 2022	M 33 - Jan 24, 2022, photo left processed	M 33 with NGC 604 - Sep 7, 2020, processed

eVscope 2


M 33 - Nov 2, 2022 (third sample)	M 33 - Dec 17, 2022 (third sample)	M 33 - Jan 18, 2023 (third sample)

M 33 - Nov 2, 2022, photo on top processed	M 33 - 17.12.2022, photo on top processed	M 33 - Jan 18, 2023, photo on top processed

M 33 with NGC 604 - Nov 2, 2022, processed	M 33 - Dec 18, 2023, 10 min	M 33 - Dec 18, 2023, photo left processed

Vespera


M 33 - Oct 30, 2022, original (270 frames = 2700s)		M 33 - Oct 30, 2022, large (270 frames = 2700s) processed

M 33 - Oct 30, 2022, original (270 frames = 2700s), processed and denoised (DN)		M 33 with NGC 604 - Oct 30, 2022, large (270 frames = 2700s), processed and denoised (DN)

Vespera Pro


M 33 - Nov 3, 2024, 2000 (361 frames = 1 h)		M 33 - Nov 3, 2024, 2000 (361 frames = 1 h), processed (PSE)

M 33 - Nov 3, 2024, 2100 (361 frames = 1 h), section, processed (TIFF)		M 33 - Nov 3, 2024, 2100 (361 frames = 1 h), section, processed (TIFF) and denoised

Ditto, with white balance, 2100		Ditto, NGC 604 marked, with white balance, 2100

M 33 - Dec 26, 2024, 2000 (241 frames = 40 min)		M 33 - Dec 26, 2024, 2000 (241 frames = 40 min), processed (PSE)

M 33 - Dec 26, 2024, 2000 (241 frames = 40 min), processed (GraXpert)		M 33 - Dec 26, 2024, 2000 (241 frames = 40 min), processed (GraXpert), made brighter and denoised (DN)

M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section		M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section, processed

M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section, denoised (TP)		M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section, denoised (TP), white balance

My Own Observations

Observations September/October 2018

Sep 28, 2018 (Sumène, Haute Loire, France: PS 72/432): M 33 probably guessed in PS72 and LT; very faint glow, framed by stars; rather large (50')
Oct 4, 2018 (Sumène, Haute Loire, France: PS 72/432, LT binoculars): M 33 seen better, nevertheless a faint glow...

Observations September/October 2019

September 19, 2019 (Sumène, France: PS 72/432 on AZ Pronto Mount): M 33 (24 mm) very faint
October 3, 2019 (Sumène, France: StarTravel 120/600 on AZ Pronto Mount): M 33 (24, 10 mm) was still a glow, but more distinct than ever before...

Observations January to March 2020

January 16, 2020 (Mühlhausen/Kraichgau: C8 on Star Discovery mount): M 33 not found with C8 in my first attempt; perhaps after a new alignment using Aldebaran, but only a very faint glow if at all (the sky was probably to bright)...
January 16, 2020 (Mühlhausen/Kraichgau: C8 on Star Discovery mount): M 33 not found with C8 in my first attempt; perhaps after a new alignment using Aldebaran, but only a very faint glow if at all (the sky was probably to bright)...
February 5-6, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed, but very faint...
February 24, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed, faint, but better than before... Found the brightest HII region NGC 604 in M 33 (comparable to a galactic emission nebula).
March 18, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed, very faint

Observations September to November 2020

September 7, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed in the new rectangular format without overlay
September 9, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed (r.f., n.o.)
September 18, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed (r.f., n.o.)
November 14, 2020 (Mühlhausen/Kraichgau: eVscope): M 33 photographed (r.f., n.o.)

Observations October to December 2021

October 7, 2021 (Erkerode: eVscope): M 33 photographed (n.o., r.f.), new image size and processing
October 9, 2021 (Erkerode: eVscope): M 33 photographed (n.o., r.f.), new image size and processing, somewhat fuzzy
December 10, 2021 (Erkerode: eVscope2): M 33 photographed (n.o., r.F.; app version 1.5)
December 21, 2021 (Erkerode: eVscope2): M 33 photographed (n.o., r.F.; app version 1.5)

Observations January to March 2022

January 6, 2021 (Erkerode: eVscope2): M 33 photographed (app version 1.5)
January 24, 2022 (Mühlhausen/Kraichgau: eVscope and eVscope2): M 33 photographed (app version 1.5)
March 19, 2022 (Mühlhausen/Kraichgau: eVscope2): M 33 photographed (app version 1.5)

Observations October/December 2022

October 30, 2022 (Mühlhausen/Kraichgau: Vespera): M 33 photographed
November 2, 2022 (Mühlhausen/Kraichgau: eVscope2): M 33 photographed (app version 2.1)
December 17, 2022 (Mühlhausen/Kraichgau: eVscope2): M 33 photographed (app version 2.2)

Observations January 2023

January 18, 2023 (Mühlhausen/Kraichgau: eVscope2): M 33 photographed (app version 2.2)

Observations December 2023

December 18, 2023 (Mühlhausen/Kraichgau: eVscope2): M 33 photographed (app version 2.5, DDT)

Observations January 2024

January 28, 2024 (Mühlhausen/Kraichgau: Vespera): M 33 photographed (45 min)
January 29, 2024 (Mühlhausen/Kraichgau: Vespera): M 33 photographed with CLS filter and as a small mosaic (4 turns)

Observations November/December 2024

November 23, 2024 (Mühlhausen/Kraichgau: Vespera Pro): M 33 photographed (60 min)
December 23, 2024 (Mühlhausen/Kraichgau: Vespera Pro): M 33 photographed (40 min)

Observations November 2025

November 21, 2025 (Mühlhausen/Kraichgau: Vespera Pro): M 33 photographed (60 min)

References

Messier Catalogue - Messier 33: messier.seds.org/m/m033.html
Messier 33 (Wikipedia): en.wikipedia.org/wiki/Messier_33
NGC 604 (H II region, Wikipedia): en.wikipedia.org/wiki/NGC_604
H II Region (Wikipedia): en.wikipedia.org/wiki/H_II_region

Websites

Drawings of Messier Deep Sky Objects (Michael Vlasov, DeepSkyWatch.com): www.deepskywatch.com/messier-dso-sketches.html
Drawings of NGC, IC and Other Objects (Michael Vlasov, DeepSkyWatch.com): www.deepskywatch.com/ngc-ic-dso-sketches.html

On this Site

Appendix: My Own Photos

eVscope


M 33 - Feb 5, 2020	M 33 - Feb 5, 2020, processed	M 33 - Feb 6, 2020, processed

M 33 - Feb 6, 2020, processed	M 33 - Feb 6, 2020, processed	M 33 - Feb 6, 2020, processed

M 33 - Feb 24, 2020	M 33 - Feb 24, 2020, processed	M 33 - Feb 24, 2020, heavily processed

M 33 - Mar 18, 2020	M 33 - Mar 18, 2020, processed	M 33 - Feb 24, 2020, processed; the arrow points to the brightest HII region in M 33, NGC 604

M 33 - Sep 7, 2020	M 33 - Sep 7, 2020, processed	M 33 - Sep 7, 2020, processed; the red dot points to the brightest HII region in M 33, NGC 604

M 33 - Sep 9, 2020, disturbed	M 33 - Sep 9, 2020, processed

M 33 - Sep 18, 2020	M 33 - Sep 18, 2020, processed

M 33 - Oct 10, 2020	M 33 - Oct 10, 2020, processed

M 33 - Oct 10, 2020	M 33 - Oct 10, 2020, processed

M 33 - Nov 14, 2020	M 33 - Nov 14, 2020	M 33 - Nov 14, 2020

M 33 - Nov 14, 2020, photo on top processed	M 33 - Nov 14, 2020, photo on top processed	M 33 - Nov 14, 2020, photo on top processed

M 33 - Oct 7, 2021	M 33 - Oct 7, 2021, somewhat fuzzy

M 33 - Oct 7, 2021, photo on top processed	M 33 - Oct 7, 2021, photo on top processed

M 33 - Jan 24, 2022	M 33 - Jan 24, 2022, photo left processed

M 33 - Jan 24, 2022	M 33 - Jan 24, 2022, photo left processed

eVscope 2


M 33 - Dec 10, 2021	M 33 - Dec 10, 2021	M 33 - Dec 21, 2021

M 33 - Dec 10, 2021, photo on top processed	M 33 - Dec 10, 2021, photo on top processed	M 33 - Dec 21, 2021, photo on top processed

M 33 - Jan 6, 2022	M 33 - Jan 24, 2022	M 33 - Mar 19, 2022

M 33 - Jan 6, 2022, photo above processed	M 33 - Jan 24, 2022, photo above processed	M 33 - Mar 19, 2022, photo above processed

M 33 - Nov 2, 2022 (third sample)	M 33 - Dec 17, 2022 (third sample)	M 33 - Jan 18, 2023 (third sample)

M 33 - Nov 2, 2022, photo on top processed	M 33 - 17.12.2022, photo on top processed	M 33 - Jan 18, 2023, photo on top processed

M 33 with NGC 604 - Nov 2, 2022, processed	M 33 - Dec 18, 2023, 10 min	M 33 - Dec 18, 2023, photo left processed

Vespera


M 33 - Oct 30, 2022, original (270 frames = 2700s)		M 33 - Oct 30, 2022, large (270 frames = 2700s) processed

M 33 - Oct 30, 2022, original (270 frames = 2700s), processed and denoised (DN)		M 33 with NGC 604 - Oct 30, 2022, large (270 frames = 2700s) processed and denoised (DN)

M 33 - Jan 28, 2024, original (250 frames = 2500s), CLS Filter		M 33 - Jan 29, 2024, large (250 frames = 2500s) CLS Filter, processed

M 33 - Jan 29, 2024, original (253 frames = 2530s), small mosaic		M 33 - Jan 29, 2024, large (253 frames = 2530s) processed

Vespera Pro


M 33 - Nov 3, 2024, 2000 (361 frames = 1 h)		M 33 - Nov 3, 2024, 2000 (361 frames = 1 h), processed (PSE)

M 33 - Nov 3, 2024, 2100 (361 frames = 1 h), section, processed (TIFF)		M 33 - Nov 3, 2024, 2100 (361 frames = 1 h), section, processed (TIFF) and denoised

Ditto, with white balance, 2100		Ditto, NGC 604 marked, with white balance, 2100

M 33 - Dec 26, 2024, 2000 (241 frames = 40 min)		M 33 - Dec 26, 2024, 2000 (241 frames = 40 min), processed (PSE)

M 33 - Dec 26, 2024, 2000 (241 frames = 40 min), processed (GraXpert)		M 33 - Dec 26, 2024, 2000 (241 frames = 40 min), processed (GraXpert), made brighter and denoised (DN)

M 33 - Nov 21, 2025, 2100 (360 frames = 1 h)		M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), processed

M 33 - Nov 21, 2025, 2100 (360 frames = 1 h)		M 33 - Nov 21, 2025, 2100 (360 frames = 1 h)

M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section		M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section, processed

M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section, denoised (TP)		M 33 - Nov 21, 2025, 2100 (360 frames = 1 h), section, denoised (TP), white balance