Messier 109 - Galaxy
This barred spiral galaxy of Hubble Type “SBbc” was found by Pierre Méchain in March 1781 and included by Charles Messier in his famous catalog in 1783.
The galaxy has an apparent magnitude of 9.8mag and a size of 7.6'x4.7' arcminutes. It is located at a distance of around 60 million light-years in the
constellation “Ursa Major” and is also the brightest galaxy in the “M109 group”, which includes 50 galaxies. Messier 109 is orbited by 3 satellite
galaxies (UGC 6923/40/69).
The diameter is given as 130,000 light-years. Specific features are a bar, loosely wound spiral arms and an inner ring of stars. The luminosity of this
large galaxy is 34 billion suns, which corresponds to an absolute magnitude of M= -21.5mag.
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When observing with my 20” telescope, Messier 109 was already quite low and dawn was slowly arriving.
As a result, the faint details were difficult to see - the galaxy was also not particularly bright due to its low surface brightness. A magnification of 210x
was best, at 270x Messier 109 lost light and details. The many beautiful spiral arms were only indicated, some of them were not visible at all. I will have
to try again under better conditions. The central area, on the other hand, appeared bright with a stellar nucleus. The bar was quite good to see, but the
beginnings of the spiral arms were only indicated.
