It’s raining stars in Norma, a massive cluster of galaxies roughly 200 light-years from Earth.
And the source of this celestial storm? A galaxy plowing right through the center of Norma.
The galaxy, known as ESO 137-001, sits in the direction of the constellation Triangulum Australe. As it’s been barging through Norma, this galaxy has dragged filaments of gas and stars in its wake. Those star streams extend 260,000 light-years! That’s more than twice the length of our galaxy, the Milky Way.
The streamers formed when ESO-137-001 slammed into hot gas. Wind from the collision has been sweeping away debris from ESO-137-001. Think of it as confetti blowing off a parade float. The released gas clouds then collapse. This ignites new stars, bringing them to life.
The Hubble Space Telescope snapped pictures of the star streams. They blaze with the intense ultraviolet radiation of those new star births (which appear blue, in false color).
constellation Patterns formed by prominent stars that lie close to each other in the night sky. Modern astronomers divide the sky into 88 constellations, 12 of which (known as the zodiac) lie along the sun’s path through the sky over the course of a year. Cancri, the original Greek name for the constellation Cancer, is one of those 12 zodiac constellations.
false color One or more hues that have been applied to a normally black-and-white image to highlight regions of significance.
galaxy A massive group of stars bound together by gravity. Galaxies, which each typically include between 10 million and 100 trillion stars, also include clouds of gas, dust and the remnants of exploded stars.
galaxy cluster A group of galaxies held together by gravity. Galaxy clusters are the largest known objects in the universe.
Milky Way The galaxy in which Earth’s solar system resides.
star Thebasic building block from which galaxies are made. Stars develop when gravity compacts clouds of gas. When they become dense enough to sustain nuclear-fusion reactions, stars will emit light and sometimes other forms of electromagnetic radiation. The sun is our closest star.
ultraviolet A portion of light spectrum that is close to violet but invisible to the human eye.