Astronomers have been studying the Andromeda galaxy, our nearest stellar neighbor to the Milky Way, using NASA’s Hubble Space Telescope. With its advanced imaging capabilities, Hubble has captured a vast mosaic of the galaxy, revealing new insights into its evolutionary history and structure.
The Andromeda galaxy is estimated to be 1 trillion stars in total, with many more awaiting detection due to Hubble’s sensitivity limit. The telescope’s sharp images have resolved over 200 million stars, providing a holistic view of the galaxy’s disk on a scale that cannot be achieved by other large galaxies.
Hubble’s survey programs, including the Panchromatic Hubble Andromeda Treasury (PHAT) and the Panchromatic Hubble Andromeda Southern Treasury (PHAST), have collectively covered the entire disk of Andromeda. The combined data reveal a galaxy with a complex history, featuring younger stars, coherent streams of stars, and an unusual structure.
Researchers believe that Andromeda’s unique features are due to its recent interaction history with other galaxies, including the compact satellite galaxy Messier 32. Computer simulations suggest that close encounters with other galaxies can lead to star formation subsidence and the eventual formation of elliptical galaxies dominated by aging red stars.
The new findings from Hubble will support future observations by NASA’s James Webb Space Telescope and the upcoming Nancy Grace Roman Space Telescope, which will capture high-resolution images of Andromeda. These observations will complement Hubble’s vast dataset, providing a more comprehensive understanding of the galaxy’s evolution and structure.
With its continued operation for over three decades, the Hubble Space Telescope has remained at the forefront of astronomical research, shaping our fundamental understanding of the universe.
Source: https://science.nasa.gov/missions/hubble/nasas-hubble-traces-hidden-history-of-andromeda-galaxy