Messier 31, the Andromeda Galaxy, is a spiral galaxy located around 2.54 million light years from Earth in the constellation Andromeda. With a size of approximately 220,000 light years across, it is the largest galaxy in the group known as the Local Group, which is also home to our own Milky Way. Andromeda has 14 known satellite galaxies. Two of the best known and readily observed are M110 and M32 and can be seen in this image. The Spitzer Space Telescope revealed in 2006 that this huge galaxy contains one trillion stars, which is more than twice as many in the Milky Way, which is estimated at around 200 to 400 billion. It is expected in 3.75 billion years that Andromeda Galaxy will collide with our Milky Way Galaxy and eventually merge to form a giant elliptical galaxy or possibly a large disc galaxy. Andromeda’s apparent magnitude of 3.4 puts it among the brightest of the Messier objects and is visible with the naked eye under dark moonless skies.
Andromeda Galaxy was described in 964, by the Persian astronomer Abd al-Rahman al-Sufi, as a “nebulous smear.” In 1612, the German astronomer Simon Marius gave a description of this galaxy based on telescopic observations. Charles Messier catalogued M31 in 1764, but incorrectly credited Marius with its discovery, despite it being naked eye visible.
Other designations: NGC 224, Messier 31, M31
Telescope: Stellarvue SV80ST Apo triplet @ f/4.8
Accessories: Stellarvue 0.8x reducer/flattener; Dew control by Dew Buster; Aurora flat panel
Mount: Takahashi EM-200 Temma2
Camera: QSI683wsg-8 CCD @ -15C
Guiding: Starlight Xpress Lodestar
Filters: Astrodon Tru-Balance E-Series Gen II LRGB filters
Exposure: Lum: 44 x 10min. binned 1x1; RGB: 24 x 5min each, all binned 2x2
Acquisition: CCD Autopilot 5; The SkyX
Processing: PixInsight 1.8
Date(s): Aug. 29-30, Sept. 1, 2016
SQM reading averaged 20.89
Location: Portland, TN, USA