Zooming In on the Andromeda Galaxy, also known as Gigapixels of Andromeda, is a 2015 composite photograph of the Andromeda Galaxy produced by the Hubble Space Telescope. It is 1.5 billion pixels in size, and is the largest image ever taken by the telescope.[1] At the time of its release to the public, the image was one of the largest ever taken.[2]
In late 2011, the Panchromatic Hubble Andromeda Treasury (PHAT) was set up,[1] which was tasked with mapping one-third of the stars within the Andromeda Galaxy. As of 2024, the survey has detected an estimated 117,000,000 astronomical objects using six light filters.[3][4]
The image depicts the right-most side[discuss] of the Andromeda Galaxy's galactic disc in visible light,[5][6] and the displayed section is approximately 61,000 light-years across.[7][8] The image shows the galaxy's 100 million stars of varying types and thousands of star clusters.[7][9][10] In the bottom-left of the image is the galaxy's nucleus, and dust lanes are also visible.[11] Several other deep-space objects are visible in the image, including background galaxies. Stars within the Milky Way are also visible, and are typically larger than stars within the Andromeda Galaxy.[12][13]
The final composite was stitched together using 411 exposures taken from July 2010 to October 2013,[14] and the image was first displayed at the 225th meeting of the American Astronomical Society in Seattle, Washington.[7][15] The mosaic is the largest and sharpest composite photograph ever taken of the Andromeda Galaxy, and the largest ever taken by the Hubble Space Telescope.[1][16] At the time of its release, the image was also one of the largest throughout all photographs.[2] The image has been used to help astronomers detect more Andromeda-like spiral galaxies using light.[5]
