NASA has targeted September 23rd for the next Artemis 1 launch attempt, but a lot is in the works
NASA’s Hubble discovered spiral stars, providing a window into the early universe
Spirals are prevalent in nature—from the whirlpools of hurricanes, to pinwheel-shaped protoplanetary disks around newborn stars, to the vast expanses of spiral galaxies in our universe.
Now astronomers are eager to find young stars orbiting at the center of a large cluster of stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way.
In this giant, oddly shaped stellar nursery called NGC 346, the outer arm of the spiral may be feeding star formation in a river-like motion of gas and stars. Scientists say this is an efficient way to stimulate star birth.
The Small Magellanic Cloud has a simpler chemical composition than the Milky Way. This makes galaxies similar to those found in the younger universe when heavy elements were much rarer. Because of this, the stars in the Small Magellanic Cloud become hotter and run out of fuel faster than our own Milky Way.
Although it can serve as a proxy for the early universe, the Small Magellanic Cloud is also one of our closest galactic neighbors, just 200,000 light-years away.
Discovering how stars form in the Small Magellanic Cloud sheds new light on how stars may have been born early in the universe’s history, when a “baby boom” was underway about 2 to 3 billion years after the Big Bang. The universe is now 13.8 billion years old).
According to the new findings, the star formation process there is similar to that of our own galaxy.
NGC 346 has a mass of 50,000 Suns despite being only 150 light-years in diameter. Its impressive size and rapid star-formation rate have surprised astronomers. Deciphering the behavior of this mysterious-looking stellar nest required the combined power of NASA’s Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope (VLT).
“Stars are the machines that sculpt the universe. We don’t have life without stars, and we still don’t fully understand how they form,” explained study leader Elena Sabbi at the Space Telescope Science Institute in Baltimore. “We have several models that make predictions, and some of these predictions are conflicting. We want to determine what is regulating the star formation process, because these are the rules that we also need to understand what we see in the early universe.
Scientists determined the motion of the stars in NGC 346 in two different ways. Using Hubble, Sabbi and her team measured changes in the stars’ positions over 11 years. Stars in this region are moving at an average speed of 2,000 miles per hour, resulting in a movement of 200 million miles in 11 years. This is twice the distance between the Sun and the Earth.
However, this cluster is relatively far away, within a neighboring galaxy. This means that the amount of motion observed from your vantage point is very small and therefore difficult to measure. These extraordinarily precise observations were made possible only by Hubble’s superior resolution and high sensitivity. In addition, Hubble’s three-decade history of observations provides a baseline for astronomers to follow celestial movements moment by moment over time.
A second team led by Peter Zedler of AURA/STScI for the European Space Agency (ESA) used the ground-based VLT’s Multi Unit Spectroscopic Explorer (MUSE) instrument to measure the radial velocity, which determines whether an object is approaching. an observer.
“What’s really surprising is that we used two completely different methods with different facilities and came to the same conclusion basically independently of each other,” Zedler said. “With Hubble, you can see the stars, but with MUSE we can also see gas moving in the third dimension, and this theory confirms that everything is rotating inward.”