M31 - The Great Galaxy in Andromeda

M31 is the famous Andromeda Galaxy. Other than our galaxy's close companions, the Large and Small Megellanic Clouds, it is our closest major galaxy. M31, along with our own Milky Way galaxy, the great spiral galaxy M33 and M31's small companion galaxies, M32 and M110 (seen here as fuzzy patches above and below M31) form what is known as our Local Group. At a distance of 2.9 million light years, it is the most distant object visible to the naked eye. Even so, it takes a keen eye and a dark night to spot it clearly. Skies must have been much clearer and darker in past ages, since M31 was known to the Persians as early as 905 AD. It also appears on a Dutch star map circa 1500 AD. It has an apparent diameter of 3 degrees...6 times the width of the full moon.

M31 is nearly twice the size of our Milky Way at 200,000 light years in diameter. However, with an estimated mass of 300 to 400 billion suns, it is not as dense as our galaxy.

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Date/Location:    September 2, 2005     Griffin/Hunter Observatory    Bethune, SC
Instrument:    Canon 350D (modified) Digital SLR through Orion ED80 w/ Meade .63 Focal Reducer piggybacked on LX-200
Focal Ratio:   Approx. f4.5
Guiding:    Auto through LX-200 w/ SBIG ST-237
Conditions:    Visually clear
Weather:    65 F, still
Exposure: 160 minutes @ ISO 800 (32 x 5 min exposures) calibrated with flat frame and Master Dark frame (average of 9 darks)
Filters:    Baader UV/IR block
Processing:    Focused and captured with DSLRFocus. RAW to TIFF conversion, frame calibrations, alignment, Digital Development, Adaptive Richardson_Lucy deconvolution, scaling and JPEG conversion with ImagesPlus. Color correction with Photoshop 6. Noise reduction with NeatImage.

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