Spiraling stars in the Small Magellanic Cloud are the subject of a recent study in ‘The Astrophysical Journal.’ Find out how their spiral motions help explain the “baby boom” of star formation shortly after the Big Bang.
At this time of the year, I enjoy looking up at the sky toward the constellations Andromeda and Cassiopeia. It’s the ideal time for me to try to spot the Andromeda Galaxy, also known as M31.
It’s the brightest galaxy we can see with the naked eye, and it’s also the closest full galaxy to the Milky Way. Since I live in the Northern Hemisphere, I’ve never had the chance to look at a couple of other easily visible neighbouring galaxies called the Large and Small Magellanic Clouds.
Astronomers classify the Magellanic Clouds as irregular dwarf galaxies, and they’re only visible south of Earth’s equator. Both Magellanic Clouds orbit our Milky Way galaxy as part of the same local group of galaxies that includes Andromeda.
Spiraling Stars in the Small Magellanic Cloud
Fortunately, the Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope don’t have my limitations. This week, The Astrophysical Journal published some of their observations regarding spiraling stars in the Small Magellanic Cloud.
The Small Magellanic Cloud has simpler chemistry than the Milky Way. It’s more like galaxies in the early universe when the heavier chemical elements were still relatively rare.
So, the Small Magellanic Cloud is nearby, bright and chemically simple. These characteristics make it an easy-to-study proxy to learn about the “baby boom” of star formation that happened 2 to 3 billion years after the universe began.
Moving Inward Toward Star Cluster’s Centre
Astronomers aimed the Hubble at the Small Magellanic Cloud to study a star cluster called NGC 346. Within NGC 346, researchers can see a series of spiraling stars slowly moving inward toward the cluster’s centre.
Professor Elena Sabbi of the Space Telescope Science Institute co-authored the study. She explained the goal of the spiraling star research this way. “We want to determine what is regulating the process of star formation, because these are the laws that we need to also understand what we see in the early universe.”
Professor Sabbi’s team analyzed 11 years of star movement in the NGC 346 cluster. Although the cluster is comparatively nearby and bright, this was still no easy task.
Call for Precise Measurements and State-of-the Art Optics
From our point of view here on Earth, the spiraling stars’ movements are minuscule. They call for unimaginably precise measurements and state-of-the-art optics.
That’s why the researchers needed the Hubble Space Telescope. Its exceptional resolution and sensitivity made the rigorous observations possible.
Hubble’s other advantage was its long history. The researchers had access to 32 years of recorded observations as benchmarks to chart the spiraling stars’ movements.
“Hubble Archive Is Really a Gold Mine”
“The Hubble archive is really a gold mine,” Professor Sabbi explained. “There are so many interesting star-forming regions that Hubble has observed over the years.”
“Given that Hubble is performing so well, we can actually repeat these observations,” she added. “This can really advance our understanding of star formation.”
Meanwhile, in Chile, study co-author Professor Peter Zeidler of the European Space Agency aimed the VLT’s Multi Unit Spectroscopic Explorer (MUSE) at NGC 346. His team’s goal was to measure whether the stars were moving toward us or away from us.
“Confirms Theory that Everything is Spiralling Inwards”
“With Hubble, you can see the stars,” Professor Zeidler explained, “but with MUSE we can also see the gas motion in the third dimension, and it confirms the theory that everything is spiraling inwards.”
”A spiral is really the good, natural way to feed star formation from the outside toward the center of the cluster,” he continued. “It’s the most efficient way that stars and gas fueling more star formation can move towards the center.”
The James Webb Space Telescope has even better resolution than Hubble. The team is hoping that it will enable them to observe lower-mass stars in the NGC 346 cluster.
Webb Will Enable Them to Observe Lower-Mass Stars
Measuring movements of less massive stars will provide further detail on spiraling star dynamics. This in turn will shed more light on how stars formed in the early universe.
Spiraling stars share their patterns with many other natural phenomena. They include whirlpools, sunflowers, DNA, seashells and hurricanes among may others.
Spiral forms follow mathematical principles. In the case of galaxies, they’re caused by stars developing at different points in time. In cases where stars in a galaxy form at roughly the same time, they create the less common elliptical galaxies instead.
Spiral Forms Follow Mathematical Principles
The spiral shape of the DNA double helix keeps the base chemicals comprising the genetic code in the middle, shielding them from water. Shells and plants follow arithmetic patterns like the Fibonacci sequence or the related Golden Ratio.
By increasing their depth, like the spiraling stars in NGC 346, spirals provide circular patterns without gaps. They do this because they’re based on irrational numbers instead of ordinary fractions, which would cause gaps.
Stars, plants and animals don’t “know” how to do any of this. It happens naturally based on the principle of parsimony. This principle suggests that entities are led to interact with each another efficiently to minimize required resources.
Universe Seems to Have Self-Organizing Property
Our universe seems to have a peculiar, self-organizing property. It remains a mystery why phenomena like spiraling stars conform to abstract, mathematical principles in the way they do.
We’re all seeking a new story that fully explains the world around us and our place in it. Gaining a more complete understanding of these interactions plays a key part in composing that narrative.
Professor Sabbi wrapped up by saying, “Stars are the machines that sculpt the universe. We would not have life without stars, and yet we don’t fully understand how they form.”
We always have more to learn if we dare to know.
NASA’s Hubble Finds Spiraling Stars, Providing Window into Early Universe
The Internal Line-of-Sight Kinematics of NGC 346: The Rotation of the Core Region
Hubble Telescope Finds Most Distant Star Ever Seen
Tidal Dwarf Galaxy Reveals Clues about Star Formation
Star Formation Started Earlier than Thought