The Andromeda galaxy, our closest galactic neighbour, has been captured in stunning detail by the Hubble Space Telescope. The massive 2.5-gigapixel panorama took 10 years and over 1,000 orbits to complete. This image is a mosaic comprising at least 2.5 billion pixels and resolves about 200 million individual stars, all hotter than our Sun.
Observing Andromeda is crucial as it offers insights into the formation and evolution of barred spirals like the Milky Way. The galaxy’s southern disk appears more disturbed, indicating effects from its merger history, which may be linked to the presence of early-type dwarf galaxy M32.
Astronomers believe that M32 could be the remnant core of a massive galaxy absorbed by Andromeda about 2-3 billion years ago. This collision may have triggered the formation of many stars and subsequent shutdown. The Giant Southern Stream, a tidal debris stream in Andromeda’s halo, supports this theory.
The new image is the result of two observing programs: PHAST and PHAT, which contributed significantly to galactic science. With 200 million individual stars observed, researchers can now study Andromeda’s history and piece together its merger and interaction history.
Future research will rely on improved telescopes like the Nancy Grace Roman Space Telescope, which is set to launch soon. This infrared telescope will capture high-resolution images of the Giant Southern Stream and provide critical clues about Andromeda’s past.
Source: https://www.universetoday.com/170498/hubble-takes-a-2-5-gigapixel-image-of-andromeda