It was a real autumn night. At times there was fog on the ground and by the end of the session the entire equipment was wet!
I lost an hour of exposure time due to a fogged up lens. Despite heating!
Object description (wikipedia.org) :
The
Andromeda Galaxy , also known as
Messier 31,
M31, or
NGC 224 and originally the
Andromeda Nebula, is a
barred spiral galaxy with diameter of about 46.56 kiloparsecs (152,000 light-years) approximately 2.5 million
light-years (770
kiloparsecs) from Earth and the nearest large galaxy to the
Milky Way.
The galaxy's name stems from the area of Earth's sky in which it appears, the
constellation of Andromeda, which itself is named after the
princess who was the wife of
Perseus in
Greek mythology.The
virial mass of the Andromeda Galaxy is of the same order of magnitude as that of the Milky Way, at 1
trillionsolar masses (2.0×1042
kilograms).
The mass of either galaxy is difficult to estimate with any accuracy, but it was long thought that the Andromeda Galaxy is more massive than the Milky Way by a margin of some 25% to 50%. This has been called into question by a 2018 study that cited a lower estimate on the mass of the Andromeda Galaxy, combined with preliminary reports on a 2019 study estimating a higher mass of the Milky Way.
The Andromeda Galaxy has a diameter of about 46.56
kpc (152,000
ly), making it the largest member of the
Local Group in terms of extension.
The Milky Way and Andromeda galaxies are
expected to collide in around 4–5 billion years, merging to form a giant
elliptical galaxy or a large
lenticular galaxy.
With an
apparent magnitude of 3.4, the Andromeda Galaxy is among the brightest of the
Messier objects, and is visible to the
naked eye from Earth on moonless nights, even when viewed from areas with moderate
light pollution.
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