One of the fascinating objects in the night sky that is visible to the naked eye is the Orion Nebula. This is the second nebula I have seen in my life, after my sister, whose name is Nebula. The Orion Nebula is a massive star-forming laboratory very close to us. If you have never seen this, go and search for the three Orion stars that look like they are in a single line. Below that, you can find three vertical points. The middle one is dim and a little bigger than the other two. That is the Orion Nebula. If you have a telescope, that’s the best object to see first.

The new study from the NeAtHood project revealed the inner structures of the Orion Nebula. This study used the combined power of the Karl G. Jansky Very Large Array (VLA) in New Mexico and the Five-hundred-meter Aperture Spherical Radio Telescope (FAST) in China. What they found is very interesting: the extended structure of the Orion Nebula, which no one had ever seen before. This gives us a lot of new understanding about this stellar nursery.

To look past the glowing dust of the Orion Nebula, astronomers focused on the 21-centimeter emission line of neutral hydrogen atoms. Mapping using this specific frequency allowed us to picture the skeletal structure of the Orion Nebula. We can blueprint the cold, diffuse gas of the Orion Nebula before it turns into stars. This allows us to see the star-forming environment before the baby stars begin to shine.

And an interesting thing astronomers found from the NeAtHood project involves the actual weight of the nebula. For many years, we relied on old techniques, which now seem to have overestimated its mass. By resolving the neutral hydrogen gas in the extended Orion Nebula with completely new details, the team found that the mass of the front hemisphere of the Orion Nebula is about 100 solar masses, a figure roughly ten times lower than previous calculations. It is not just a change in numbers; it actually changes our fundamental understanding of stellar nurseries.

The lead author, Juan Diego Soler, an astrophysicist at the University of Vienna, says:

“Measuring mass is fundamental. It tells us about the efficiency of these newly formed stars shaping their environment with wind and radiation.”

We can now understand how effectively young stars clear out their surroundings and how much fuel is left behind to form new suns.

Beyond the missing mass, the team found another surprising thing: a ghostly second cavity inside the extended Orion Nebula. For a long time, scientists thought all these structures were created by a single event. But the new data tells a different story.

The study suggests that the Orion Nebula was shaped in more than one stage. The main bubble was first carved out by the powerful winds and radiation from the massive star Theta Orionis C. Later, another massive star moving through the Orion Nebula Cluster created a second bubble. These two bubbles overlap with each other. This tells us that star formation here was not a single event, but happened in different stages over time.

And scientists found a linear bump extending about 4 parsecs (roughly 13 light-years) away from the shell of the Orion Nebula. Some theories argue that this structure was created by a supernova explosion. But scientists now argue that it more closely resembles the effect of powerful, long-lasting stellar winds and radiation from a young, massive star.

“These are the kind of images that challenge the theoretical models and numerical simulations that we use to understand how massive stars affect their immediate surroundings.”

– Daniel Seifried

The results of this project not only changed our understanding of the Orion Nebula, but also how young stars affect their surroundings. For decades, we relied on older theoretical approaches, and our simulations were based on them. This new discovery is now challenging those old theoretical ideas.

“An exciting demonstration of the power of latest-generation radio telescopes to uncover new pieces of the star formation puzzle.”

– Claire Murray