Hubble Space Telescope presents Christmas star globe
The billion stars of galaxy UGC 8091 resemble a bright snowball in this festive image from NASA and ESA’s Hubble Space Telescope.
Irregular galaxy
As reported by NASA in Spanish, the dwarf galaxy is located approximately 7 million light years from Earth in the Virgo constellation. It is considered an «irregular galaxy» because it does not have an ordered spiral or elliptical appearance. Instead, the stars that make up this celestial gathering look more like a tangle of bright string lights than a galaxy.
Exploring irregular galaxies
Some irregular galaxies may have become entangled due to tumultuous internal activity, while others have formed by interactions with neighboring galaxies. The result is a class of galaxies with a wide range of sizes and shapes, including the diffuse scattering of stars that is this galaxy.
Twelve camera filters were combined to produce this image, with light from the mid-ultraviolet to the red end of the visible spectrum. The red spots are probably interstellar hydrogen molecules that shine because they have been excited by the light of hot and energetic stars. The other flares shown in this image are a mix of older stars. A series of diverse and distant galaxies appear in the background, captured by Hubble’s sharp vision.
The data used in this image was taken by the Wide Field Camera 3 of Hubble and the Advanced Camera for Surveys from 2006 to 2021.
Among other things, the observing programs involved in this image sought to investigate the role that dwarf galaxies played many billions of years ago in reheating hydrogen that had cooled as the universe expanded after the Big Bang.
Astronomers are also investigating the composition of dwarf galaxies and their stars to discover evolutionary links between these ancient galaxies and more modern galaxies like our own.
This article was published on December 21, 2023.