Stars from colliding galaxies come together in a newly enhanced image from NASA’s venerable space telescope.
The Hubble Space Telescope has been hard at work for more than three decades, and scientists never lose their fascination with the observatory’s vast archive. Take, for example, this “river of star formation,” as NASA officials called it in a statement released Wednesday, May 17, which takes place at an intersection of four dwarf galaxies within the Hickson Compact Group 31 (HCG 31) of galaxies.
The image was first published in 2010 and has been redesigned to highlight star forming regions. The blue in the image represents visible blue light, in which several hot young blue stars glow, particularly in a pair of colliding dwarf galaxies collectively called the galaxy NGC 1741 (top right of center). Red shows light in the near infrared.
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“Another cigar-shaped dwarf galaxy at [NGC 1741]The right joins their dance with a thin blue streak of stars connecting the trio,” NASA said. A fourth member, HGC 31, is visible in the lower left. There is also a bright star in the galaxy path of the quartet, which you can see in the center of the picture.
Hubble has photographed galaxies in detail for a generation, and many images released in recent weeks have focused on galaxy collisions. For example, in February the program released a pair of galaxies known as Arp 298, interacting 200 million light-years from Earth in the constellation Pegasus.
Arp 298 is also one of the first science targets for observations by the new James Webb Space Telescope starting in the summer of 2022, Hubble officials said at the time. The $10 billion observatory is in its final weeks of commissioning and can render sharp images in many configurations; it will soon be evaluated in warmer and cooler conditions and for closer solar system objects.
Hubble will assist Webb for a few years in the main task of the new observatory, which is to understand the evolution of the universe. The galaxies that formed around the beginning of the universe will be studied, to trace how this group was different from the galaxies of today.
A notable difference from the beginning of our universe’s history is the lack of heavier elements and the relative abundance of hydrogen and helium. But tracing galaxy change and changes in dark matter, which cannot be detected directly but seen through their influence on nearby objects, will be part of Webb’s work.