Andromeda Galaxy (M31)

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Astronomers place the Andromeda Galaxy at 2.5 million light years from Earth. When light photons left Andromeda on their way to Earth 2.5 million years ago, homo habilis (“Handy Man”) had not yet started roaming East Africa. A short few hundred thousand years later, homo habilis became one of the first human ancestors to use stone tools. Mary and Louis Leakey discovered remains of homo habilis in the early 1960’s in Olduvai Gorge.

Light photons would have left Andromeda at the dawn of Earth’s Pleistocene Age, marked by numerous Ice Ages and Glaciation. The Pleistocene Age began roughly 2.5 million years ago, and ended about 11,000 years ago.

Object Data

The Andromeda Galaxy is one of the Local Group of galaxies, and is currently thought to be approximately the same size as our Milky Way galaxy. Also identified by Charles Messier as M31, Andromeda is approaching our Milky Way galaxy at a speed of 300 kilometers per second. It is expected that Andromeda and the Milky Way will collide in roughly 3.75 billion years, and morph from spiral galaxies into one larger elliptical galaxy.



Date: December 31 08
Location: Tucson, Arizona backyard
Telescope: Takahashi FSQ106
Focal Length: 500mm
f/ratio: f/5.1
Mount: Astrophysics 900GTO
Camera: SBIG STL11000
Exposure: Lum:28@5min, Red:15@5min; Green:17@5min; Blue:15@5min. All exposures unbinned.
Processing Notes:

LRGB, reprocessed April 2013. CCDStack, Photoshop CS6, using, among other techniques, R. Jay Gabany’s ‘Layered Contrast Stretching’ featured in Sky & Telescope, June, 2011.