M104 - Sombrero Galaxy
Messier 104 or M104 (also designated NGC 4594) is a spiral galaxy in the constellation Virgo. It has an apparent visual magnitude of 8 and its angular diameter is 9x4 arc-minutes. M104 lies at an estimated distance of 50 million light years. The Equinox 2000 coordinates are RA= 12h 40m, Dec= -11° 37´ which makes M104 best seen during the spring. The Messier Spring Star Chart shows the position of all Messier objects visible during that season. As one of the more famous objects in the Messier Catalog, it is commonly known as the Sombrero Galaxy.
The image above shows the uncropped view of M104 through the Takahashi E-180 Astrograph (North is up). A 3x enlargement of this image appears to the right.
This spiral galaxy was discovered by P. Méchain in 1781. The Sombrero Galaxy gets its name from the dark lane of dust that bisects the galaxy. According to Stoyan et al. (2010), the distance of M104 is 44.7 million light years and its diameter is 105,000 light years. Its estimated mass is 300 billion solar masses.
Messier's Description of M104
Messier's handwritten note in his copy of the Connoissance des Temps for 1784)
(May 11, 1781).
`Very faint nebula, seen by M. Méchain on May 11, 1781.'
Méchain in his letter to Bernoulli, May 6, 1783)
`On May 11, 1781, I discovered a nebula above the Raven [Corvus] which did not appear to me to contain any single star. It is of a faint light and difficult to find if the micrometer wires are illuminated. I have compared it [its position] on this day and the following with Spica in the Virgin and from this derived its right ascension 187d 9' 42" and its southern declination 10d 24' 49" [the same position as in Messier's handwritten note]. It does not appear in the Connoissance des Temps.'
- Object: M104
- Other Names: NGC 4594, Sombrero Galaxy
- Object Type: spiral galaxy
- Object Data: Apparent Magnitude = 8, Angular Size = 9x4 arc-minutes
- Object Position (Equinox 2000): RA= 12h 40m, Dec= -11° 37´, Constellation = Virgo
- Date/Time: 2011 Apr 04 at 05:47 UTC
- Location: Bifrost Astronomical Observatory, Portal, AZ
- Mount: Astro-Physics 1200GTO
- Telescope: Takahashi Epsilon 180 Hyperbolic Astrograph
- Camera: Canon EOS 550D (Rebel T2i) (modified with a Baader UV/IR filter)
- Field of View: 1.70° x 2.56° at 1.7 arc-sec/pixel (web version: 10.0 arc-sec/pixel)
- Exposure: 4 x 300s, f/2.8, ISO 800
- File Name: M104-01w.jpg
- Processing (Adobe Camera Raw): Graduated Filter, Vignetting Correction, Noise Reduction, White Balance, Curves
- Processing (Photoshop CS5): Average Images, Curves, Noise Reduction
- Original Image Size: 3454 × 5179 pixels (17.9 MP); 11.5" x 17.3" @ 300 dpi
- Rights: Copyright 2011 by Fred Espenak. All Rights Reserved. See: Image Licensing.