M104 - Sombrero Galaxy
| Polish version is here |
The Sombrero Galaxy, also known as M104, is one of the most recognizable and striking galaxies in the night sky. Its name comes from its characteristic appearance, resembling a straw or felt sombrero with a soft, wide brim (Figure 1). This remarkable galaxy, visible in the constellation Virgo (close to the boundary with Corvus), fascinates both professional astronomers and space enthusiasts worldwide.
Pierre Méchain discovered the galaxy on May 11, 1781. Although it was not included in the originally published version of Messier’s catalog, Charles Messier personally added it to his private copy of the catalog. Independently, William Herschel rediscovered the galaxy on May 9, 1784, and John Dreyer later included Herschel’s observation in his catalog as NGC 4594. In 1917, Camille Flammarion determined that NGC 4594 had previously been observed by Méchain and was known to Messier. As a result, in 1921, Flammarion added the galaxy to the Messier catalog as number 104.
The Sombrero Galaxy ranks among the most frequently photographed objects in space. Its distinct structure and unique appearance make it a popular target not only for professional astronomers but also for amateur stargazers equipped with suitably powerful telescopes.
Observations
May 26, 2024, around 11:00 PM – Jaworzno (Poland), garden
urban conditions, high level of light pollution
As I set up my equipment that night and aimed it toward Virgo, I was unsure whether anything would appear in the photos, given the significant light pollution in this part of the sky. To my delight, the galaxy’s characteristic outline appeared after only a few minutes of exposure. The following photograph was captured after nearly an hour and a half of exposure.
The Sombrero Galaxy is located approximately 30 million light-years from Earth and has a diameter of about 60,000 light-years. This galaxy is notable for its abundance of globular clusters, which form a spherical halo surrounding it.
The Sombrero Galaxy features a large, bright core and surprisingly faint spiral arms. Many astronomers classify it as a peculiar galaxy, and its classification as a spiral galaxy is somewhat ambiguous and remains a topic of debate. When viewed edge-on, the galaxy is partially obscured by a torus of material composed mainly of dust and cold, non-luminous interstellar gas. It is classified as an active galactic nucleus (AGN). Both the activity of its core and possible star-forming processes within the torus contribute to M104's enduring scientific interest among astronomers.
Photo 1 Parameters:
- Total exposure time: 80 minutes (stack of 160 RAW frames at 30s each, using an appropriate number of dark, bias, and flat frames)
- Canon EOS 60D
- ISO: 1600
- Newton telescope (150/750), prime focus exposure
- A filter was used to reduce the effects of artificial light pollution and atmospheric glow
- Mount: equatorial mount with tracking, aligned using the drift method and controlled by a custom-built system
Further readings:
- Desselberger J., Niebo nad Polską, Urania - Postępy Astronomii, 2015, 1(775), str. 66
- Mcquinn K. B. W. Skillman E. D., Dolphin A. E., Berg D., Kennicutt R., The Distance To M104, The Astronomical Journal, 2016, 152(5), str. 144-151
- Bendo G. J., Buckalew B. A., Dale D. A., Draine B. T., Joseph R. D., Kennicutt R. C., Spitzer and JCMT Observations of the Active Galactic Nucleus in the Sombrero Galaxy (NGC 4594), The Astrophysical Journal, 2006, 645(1), str 134-147
Marek Ples