M109
M109 - Click here for full resolution
Messier 109 is a barred spiral galaxy located in the constellation Ursa Major, approximately 83.5 million light-years from Earth. M109 was discovered by Pierre Méchain in 1781 and later cataloged by Charles Messier. It is one of the brightest galaxies in the Ursa Major Cluster, a group of galaxies. M109 is notable for its prominent central bar structure. The galaxy has a magnitude of about 9.8. It spans roughly 180,000 light-years in diameter, making it slightly larger than the Milky Way. M109 is also known for its active star-forming regions and a bright nucleus, which may harbour a supermassive black hole.
source: DeepSeek
NGC/IC:
Other Names:
Object:
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Dec:
Distance to Earth:
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Transit date:
Tr. Alt (Oria, Spain):
NGC3992
n.a.
Galaxy
Ursa Major
11h 57m 36s
+53° 22.4′
83 million ly
9.8
08 April
74º N
Conditions
M109 is best visible during Winter and early Spring. During this time It reaches high altitudes, well over 70°, when observed from the remote observatory at IC Astronomy in Oria , Spain. M109 was photographed from the observatory in Spain over 4 nights, during mid February 2025. The distance to an almost full moon was pretty close during the first session, but got much better over subsequent sessions.
Equipment
The default rig at the observatory was used. The core of this rig is a Planewave CDK-14 telescope on a 10Micron GM2000 mount, coupled to a Moravian C3-61000 Pro full-frame camera. The RoboTarget module in Voyager Advanced automated the process to find optimal time-slots during astronomical night.
Telescope
Mount
Camera
Filters
Guiding
Accessoires
Software
Planewave CDK14, Optec Gemini Rotating focuser
10Micron GM2000HPS, custom pier
Moravian C3-61000 Pro, cooled to -10 ºC
Chroma 2” Luminance, Red, Green and Blue unmounted, Moravian filterwheel L, 7-position
Unguided
Compulab Tensor I-22, Windows 11, Dragonfly, Pegasus Ultimate Powerbox v2
Voyager Advanced, Viking, Mountwizzard4, Astroplanner, PixInsight 1.9.2
Imaging
M109 is a typical broadband object and default exposure times were used. This means 3 minutes for luminance and 5 minutes for each of the Red, Green and Blue filters. The total exposure was 20 h. All subs taken were of sufficient quality and made it into the final stack.
Resolution (original)
Focal length
Pixel size
Resolution
Field of View
Rotation
Image center
6000 x 4000 px (24 MP)
2585 mm @ f/7.3
3.8 µm
0.30 arcsec/px
30' x 20'
0.074°
RA: 11h 57m 36.236s
Dec: +53° 22’ 36.91”
Processing
All images were calibrated using Darks (50), Flats (50) and Flat-Darks (50), registered and integrated using the WeightedBatchPreProcessing (WBPP) in PixInsight. All further processing was done in PixInsight, including the use of scripts and tools developed by RC-Astro, SetiAstro, GraXpert, and others. For a step-by-step description of the processing techniques applied, see process flow below.
To maintain colour in the RGB image, GHS stretching was performed in the ‘Colour’ mode. A simple increase in saturation after stretching was enough to create the right level of colour nuances. When the Luminance was stretched, a few small remains of some dust bunnies remained visible in the background, which were apparently not completely calibrated out using the flats. Before stretching they were cloned out of the starless image using the CloneStamp tool.
Processing followed a very standard pattern.
Processing workflow (click to enlarge)
This image has been published on Astrobin
