New radio telescope observations have brought a new lens on one of our universe’s most beautiful stellar nurseries.
Why it matters
Having a clearer sense of what star-forming regions look like could help us understand how stars have formed since the dawn of time. And why they’re still forming as you read this.
About 170,000 light-years from where you’re sitting – which sounds terribly far but is actually relatively close on a cosmic scale – lies an astronomical marvel. It’s a glorious stellar nursery decorated with breathtaking swirls and iridescent streaks, illuminating space’s void by violently birthing newborn stars.
Since its genesis, in fact, experts believe this bundle of interstellar dust and gas has witnessed the dawn of more than 800,000 stars and protostars in our universe, half a million of which are hot, young and absolutely massive. Some are even thought to carry a mass of about 150 times that of our sun. You know, the stellar body that makes up something like 99.8% of the mass of our entire solar system.
And, thanks to new research published Wednesday in The Astrophysical Journal, we Earthlings have the privilege of admiring this spectacle with a level of detail never experienced before. Better yet, upon peering through this new lens on the nebula, you might also catch a glimpse of the reasoning behind its very metal name.
It’s known as the Tarantula Nebula, and it looks just like a cosmic web.
Painting stellar artwork
By harnessing a world-class radio telescope called the Atacama Large Millimeter / submillimeter Array, scientists managed to reveal ultra-high-resolution depictions of the magnificent Tarantula Nebula.
Basically, in the team’s newly released images, you’ll see lava-like wisps and feathery lines come to life as a result of ALMA’s super precise light emission measurements.
The structure of this nebula – also called 30 Doradus in reference to its catalog number in the list of objects of the constellation Dorado – can be traced by detecting carbon monoxide gas content in the area scientists believe it’s located. ALMA’s emission measurements can do just that.
And scientists are after these carbon monoxide remnants simply because they signify the location of cold clouds which are known to collapse and form baby stars. And baby stars form in stellar nurseries, like 30 Doradus. If scientists can figure out where those gas clouds are, they can get a pretty clear visualization of what the outline of 30 Doradus looks like.
Think of it like working backwards.
Then the research team overlaid the gas cloud outline with a previous infrared image of the same area that shows hot cosmic gas, indicated by pinkish puffs, and bright speckles of stars adorning an indigo background of space – the rest of the scene.
Slap it all together, and we get the awesome composite image.
But besides the artistic element of the team’s star nursery cartography efforts, there’s a practical reason for understanding what the Tarantula Nebula looks like.
Beyond beauty lies discovery
“What makes 30 Doradus unique is that it is close enough for us to study in detail how stars are forming, and yet its properties are similar to those found in very distant galaxies, when the universe was young,” Guido de Marchi, a scientist at the European Space Agency and co-author of the paper, said in a statement.
“Thanks to 30 Doradus,” de Marchi said, “we can study how stars used to form 10 billion years ago, when most stars were born.”
To begin working toward that end-goal, the team harnessed its new dataset to decode the way gravity affects stellar generation in 30 Doradus and how energy released from newly birthed stars slows the overall assembly line of star formation. Both of these bits are considered integral to dissecting star formation processes, and the latter one in particular is represented in the new image by some of the lit-up pieces we see.
“These fragments may be the remains of once-larger clouds that have been shredded by the enormous energy being released by young and massive stars, a process dubbed feedback,” Tony Wong, a professor at the University of Illinois at Urbana-Champaign and lead author of the new research, said in a statement.
The results were striking.
“We were expecting to find that the parts of the cloud closest to the young, massive stars would show the clearest signs of gravity being overwhelmed by feedback, and as a result, a lower rate of star formation,” Wong said.
But Wong was surprised to see a different story when gazing at ALMA’s new observations. “These observations confirmed that even in a region with extremely active feedback,” he said, “gravity’s presence is still strongly felt and star formation is likely to continue.”
In other words, nascent stars spitting up energy do not appear to mess up gravity around the stellar nursery or slow star formation. Star babies prevail.
OK, unless you’re an astronomer, this discovery might sound kind of nitty gritty. But zooming out, the team hopes that understanding the ins and outs of the Tarantula Nebula’s workings could inform what might be considered one of the biggest mysteries of astronomy.
“Why didn’t all of the available gas collapse in a huge fireworks show long ago?” Wong said. “What we’re learning now can help us shine a light on what is happening deep within molecular clouds so that we can better understand how galaxies sustain star formation over time.”
Plus, in the vein of curiosity and science, Wong said, “there is still much more to do with this fantastic dataset, and we are releasing it publicly to encourage other researchers to conduct new investigations.”