LEDA 1313424, Bullseye Galaxy

Prelims – Current events of national and international importance

Mains (GS III) – Science and Technology- Awareness in the fields of Space

Why in News?

A team of international researchers recently discovered a galaxy with nine rings, named Bullseye.

• It is a collisional ring galaxy discovered recently by NASA’s Hubble Space Telescope.
• Size - It is nearly 2.5-times larger than the Milky Way with a diameter of 250,000 light-years.
• Type - Spiral galaxy.
• A blue dwarf galaxy, positioned at the center-left of the image, is believed to have interacted with the Bullseye Galaxy approximately 50 million years ago.
  • It results in the distinctive shape of the Bullseye Galaxy.
• A thin trail of gas connecting the two galaxies even though they are separated by 130,000 lightyears (or 1.22 billion billion km).
• The blue dwarf galaxy’s straight path through the Bullseye Galaxy caused gas in the latter to ripple back and forth in waves, creating new places of star formation.
• The interaction didn’t alter the orbits of individual stars but it caused groups of stars to pile up and form the distinct rings over millions of years.
• Bullseye hosts a lot of neutral hydrogen gas, considering its mass in stars.
• That reservoir of star-forming material is similar to known low surface brightness galaxies, strengthening the notion that collisional ring galaxies evolve into these fainter objects as their rings fade.
• The Bullseye Galaxy will continue to evolve and, as a result, will have these star-filled rings only for a short interval of time.
• This means the astronomers captured an intriguing image of a multi-ring galaxy in a special moment.
• Bullseye Galaxy also contains signs that it could one day evolve into a giant low surface brightness (GLSB) galaxy, which are important in the study of dark matter.

Giant low surface brightness (GLSB) galaxies are the largest of the low surface-brightness galaxies. All GLSB galaxies are truly colossal.

Reference

The Hindu | Bullseye Galaxy