- When galaxies collide, they prepare dinner up new generations of stars. These galactic collisions trigger a gravitational tug-of-war, and gasoline and dust are drawn out into giant streamers.
- The knots of gasoline gravitationally collapse to create about 1 million new child stars per cluster within the lengthy tidal tails.
- These “string of pearls” options are most likely extra frequent within the early universe when galaxies collided extra incessantly.
NASA revealed this original article on February 8, 2024. Edits by EarthSky.
String of pearls are born when galaxies collide
Opposite to what you may assume, galaxy collisions don’t destroy stars. The truth is, the rough-and-tumble dynamics set off new generations of stars, and presumably accompanying planets.
Now NASA’s Hubble Space Telescope has homed in on 12 interacting galaxies which have lengthy, tadpole-like tidal tails of gasoline, dust and a plethora of stars. Hubble has uncovered 425 clusters of new child stars alongside these tails, wanting like strings of vacation lights. Every cluster incorporates as many as 1 million blue, new child stars.
We’ve identified about clusters in tidal tails for many years. When galaxies work together, gravitational tidal forces pull out lengthy streamers of gasoline and dust. Two standard examples are the Antennae and Mice galaxies with their lengthy, slim, finger-like projections.
A brand new examine of tidal tails
A crew of astronomers published a brand new examine on September 29, 2023, utilizing a mix of latest observations and archival knowledge to get ages and much of tidal tail star clusters. They discovered that these clusters are very younger: solely 10 million years outdated. They usually’re forming on the similar charge alongside tails stretching for 1000’s of light-years.
Lead writer Michael Rodruck of Randolph-Macon School in Ashland, Virginia, stated:
It’s a shock to see numerous the younger objects within the tails. It tells us lots about cluster formation effectivity. With tidal tails, you’ll construct up new generations of stars that in any other case won’t have existed.
The tails appear to be they’re taking a galaxy’s spiral arm and stretching it out into space. The outside a part of the arm will get pulled like taffy from the gravitational tug-of-war between a pair of interacting galaxies.
Earlier than the mergers, the galaxies had been wealthy in dusty clouds of molecular hydrogen that merely might have remained inert. However the clouds obtained jostled and ran into one another through the encounters. This compressed the hydrogen to the purpose the place it precipitated a firestorm of star beginning.
What is going to occur subsequent?
The destiny of those strung-out star clusters is unsure. They could keep gravitationally intact and evolve into globular star clusters, like those who orbit exterior the airplane of our Milky Way galaxy. Or they could disperse to kind a halo of stars round their host galaxy, or get solid off to turn into wandering intergalactic stars.
This string-of-pearls star formation might have been extra frequent within the early universe when galaxies collided with one another extra incessantly. These close by galaxies that Hubble noticed are a proxy for what occurred way back. Due to this fact, they’re laboratories for wanting into the distant previous.
Backside line: This stunning galaxy is considered one of many who Hubble has noticed exhibiting a “string of pearls.” When galaxies collide, new star formation creates these clusters within the tidal tails.
Source: Star clusters in tidal debris
