TrevorW
28-03-2009, 03:47 PM
Target : NGC4594 M104 Sombrero Galaxy
Camera: Canon 350d modified
Exposure Capture: DSLR Capture
Scope: Stellarvue 80ED f/7 /2x Barlow
Mount: EQ6 Pro
Exposure Setting: Prime focus, ISO800 ICNR off Daylight WB
Exposures: 10 x 480 second, 15 x 90 seconds total 1hr 42.5m collected 27/3/09
Seeing: Average to poor, high humidity warm night.
Guiding: Orion Starshoot Autoguider using PHD, 10x60 SV Guide Scope
Focus: DSLR Focus
Stacking: 26 frames stacked in DSS, 5 corresponding dark 480s frames, 8 corresponding 90s darks, plus flats which took nearly 1 hour to stack 2x drizzle. Processing in Photoshop CS3, auto levels, color and contrast. Used Noel Carboni’s PS actions to enhance DSO and make stars smaller, light pollution removal.
I dedicate this image to my mother who passed away this week aged 90, may she rest in peace.
Information: Situated in Virgo
RA 12:40 (h:m) DEC-11:37 (deg:m) Distance 50000 (kly) Visual Brightness 8.0 (mag) Apparent Dimension 9x4 (arc min) Discovered by Pierre Méchain in 1781. Messier 104 (M104, NGC 4594) is numerically the first object of the catalog which was not included in Messier's originally published catalog. However, Charles Messier (http://seds.org/messier/xtra/history/biograph.html) added it by hand to his personal copy on May 11, 1781, and described it (http://seds.org/messier/xtra/history/m-cat.html#M104) as a "very faint nebula." It was Camille Flammarion (http://seds.org/messier/xtra/Bios/flammarion.html) who found that its position coincided with Herschel's H I.43, which is the Sombrero Galaxy (NGC 4594), and added it (http://seds.org/messier/addition.html) to the official Messier list in 1921. This object is also mentioned by Pierre Méchain (http://seds.org/messier/xtra/history/pmechain.html) as his discovery in his letter of May 6, 1783 (http://seds.org/messier/xtra/history/pm-lett.html#m104). William Herschel (http://seds.org/messier/xtra/Bios/wherschel.html) found this object independently on May 9, 1784.
This brilliant galaxy was named the Sombrero Galaxy because of its appearance. According to de Vaucouleurs, we view it from just 6 degrees south of its equatorial plane, which is outlined by a rather thick dark rim of obscuring dust. This dust lane was probably the first discovered, by William Herschel in his great reflector. This galaxy is of type Sa-Sb, with both a big bright core, and as one can see in shorter exposures, also well-defined spiral arms. It also has an unusually pronounced bulge with an extended and richly populated globular cluster system - several hundred can be counted in long exposures from big telescopes.
Recent very deep photographs from the Anglo-Australian Observatory show that this galaxy has a very extended faint halo (http://seds.org/messier/more/m104_deep.html). This galaxy was the first one with a large redshift found, by Vesto M. Slipher at Lowell Observatory in 1912. Its redshift corresponds to a recession velocity of about 1,000 km/sec (it is caused by the Hubble effect, i.e. the cosmic expansion). This was too fast for the Sombrero to be an object in our Milky Way galaxy. Slipher also detected the galaxy's (then the nebula's) rotation. M104 is the dominating member of a small group of galaxies, the M104 group (http://seds.org/messier/more/m104gr.html) or NGC 4594 group of galaxies.
Camera: Canon 350d modified
Exposure Capture: DSLR Capture
Scope: Stellarvue 80ED f/7 /2x Barlow
Mount: EQ6 Pro
Exposure Setting: Prime focus, ISO800 ICNR off Daylight WB
Exposures: 10 x 480 second, 15 x 90 seconds total 1hr 42.5m collected 27/3/09
Seeing: Average to poor, high humidity warm night.
Guiding: Orion Starshoot Autoguider using PHD, 10x60 SV Guide Scope
Focus: DSLR Focus
Stacking: 26 frames stacked in DSS, 5 corresponding dark 480s frames, 8 corresponding 90s darks, plus flats which took nearly 1 hour to stack 2x drizzle. Processing in Photoshop CS3, auto levels, color and contrast. Used Noel Carboni’s PS actions to enhance DSO and make stars smaller, light pollution removal.
I dedicate this image to my mother who passed away this week aged 90, may she rest in peace.
Information: Situated in Virgo
RA 12:40 (h:m) DEC-11:37 (deg:m) Distance 50000 (kly) Visual Brightness 8.0 (mag) Apparent Dimension 9x4 (arc min) Discovered by Pierre Méchain in 1781. Messier 104 (M104, NGC 4594) is numerically the first object of the catalog which was not included in Messier's originally published catalog. However, Charles Messier (http://seds.org/messier/xtra/history/biograph.html) added it by hand to his personal copy on May 11, 1781, and described it (http://seds.org/messier/xtra/history/m-cat.html#M104) as a "very faint nebula." It was Camille Flammarion (http://seds.org/messier/xtra/Bios/flammarion.html) who found that its position coincided with Herschel's H I.43, which is the Sombrero Galaxy (NGC 4594), and added it (http://seds.org/messier/addition.html) to the official Messier list in 1921. This object is also mentioned by Pierre Méchain (http://seds.org/messier/xtra/history/pmechain.html) as his discovery in his letter of May 6, 1783 (http://seds.org/messier/xtra/history/pm-lett.html#m104). William Herschel (http://seds.org/messier/xtra/Bios/wherschel.html) found this object independently on May 9, 1784.
This brilliant galaxy was named the Sombrero Galaxy because of its appearance. According to de Vaucouleurs, we view it from just 6 degrees south of its equatorial plane, which is outlined by a rather thick dark rim of obscuring dust. This dust lane was probably the first discovered, by William Herschel in his great reflector. This galaxy is of type Sa-Sb, with both a big bright core, and as one can see in shorter exposures, also well-defined spiral arms. It also has an unusually pronounced bulge with an extended and richly populated globular cluster system - several hundred can be counted in long exposures from big telescopes.
Recent very deep photographs from the Anglo-Australian Observatory show that this galaxy has a very extended faint halo (http://seds.org/messier/more/m104_deep.html). This galaxy was the first one with a large redshift found, by Vesto M. Slipher at Lowell Observatory in 1912. Its redshift corresponds to a recession velocity of about 1,000 km/sec (it is caused by the Hubble effect, i.e. the cosmic expansion). This was too fast for the Sombrero to be an object in our Milky Way galaxy. Slipher also detected the galaxy's (then the nebula's) rotation. M104 is the dominating member of a small group of galaxies, the M104 group (http://seds.org/messier/more/m104gr.html) or NGC 4594 group of galaxies.