Lifting the veil on star formation in the Orion Nebula

January 10, 2019, University of Cologne
The powerful wind from the newly formed star at the heart of the Orion Nebula is creating the bubble (black) and preventing new stars from forming in its neighbourhood. At the same time, the wind pushes molecular gas (colour) to the edges, creating a dense shell around the bubble where future generations of stars can form. Credit: NASA/SOFIA/Pabst et al.

The stellar wind from a newborn star in the Orion Nebula prevents more new stars from forming nearby. That is the result of new research conducted by an international research team led by the University of Cologne (Germany) and the University of Leiden (Netherlands) using NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA).

The result is surprising because until now, scientists thought that other processes, such as exploding stars (supernovae), were largely responsible for regulating the formation of stars. But SOFIA's observations suggest that infant stars generate stellar winds that can blow away the seed material required to form new stars, a process called feedback. The paper, "Disruption of the Orion Molecular Core 1 by the of the massive star θ1 Ori C," has now been published in Nature.

The Orion Nebula is among the best observed and most photographed objects in the night sky. It is the closest stellar nursery to Earth, and helps scientists explore how stars form. A veil of gas and dust makes this nebula extremely beautiful, but also shrouds the entire process of star birth from view. Fortunately, can pierce through this cloudy veil, allowing specialized observatories like SOFIA to reveal many of the star-formation secrets that would otherwise remain hidden.

At the heart of the nebula lies a small grouping of young, massive and luminous stars. Observations from SOFIA's instrument, the German Receiver for Astronomy at Terahertz Frequencies (GREAT), revealed for the first time that the strong stellar wind from the brightest of these baby stars, Theta1 Orionis C (θ1 Ori C), has swept up a large shell of material from the cloud where this star formed, like a snow plow clearing a street by pushing snow to the road's edges.

"The wind is responsible for blowing an enormous bubble around the central stars," explained Cornelia Pabst, a doctoral researcher at the University of Leiden and lead author of the paper. "It disrupts the natal cloud and prevents the birth of new stars."

Researchers used the GREAT instrument on SOFIA to measure the spectral line, which is like a chemical fingerprint, of ionized carbon. SOFIA's airborne location is above 99 percent of the water vapour in the Earth's atmosphere, which blocks infrared light, so the researchers were able to study the physical properties of the stellar wind.

"The large-scale Orion C+ observation demonstrates that such scale mapping is possible with SOFIA/upGREAT. The multi-pixel SOFIA/upGREAT receiver allows us to map larger regions in a shorter time compared to previous instruments. It is about 80 times faster than the single pixel HIFI receiver onboard the ESA cornerstone mission Herschel," says Ronan Higgins, who led the investigation from the University of Cologne's side.

Similarly, the astronomers use the ionized carbon's spectral signature to determine the speed of the gas at all positions across the nebula and study the interactions between massive stars and the clouds where they were born. The signal is so strong that it reveals critical details and nuances of the stellar nurseries that are otherwise hidden. But this signal can only be detected with specialized instruments—like GREAT—that can study far-infrared light.

At the center of the Orion Nebula, the stellar wind from θ1 Ori C forms a bubble and disrupts star birth in its neighbourhood. At the same time, it pushes molecular gas to the edges of the bubble, creating new regions of dense material where future stars might form.

These feedback effects regulate the physical conditions of the , influence the star formation activity and ultimately drive the evolution of the interstellar medium, the space between stars filled with gas and dust. Understanding how star formation interacts with the interstellar medium is key to understanding the origins of the we see today, and those that may form in the future.

Explore further: What's happening in Orion's Horsehead Nebula?

More information: C. Pabst et al, Disruption of the Orion molecular core 1 by wind from the massive star θ1 Orionis C, Nature (2019). DOI: 10.1038/s41586-018-0844-1

Related Stories

What's happening in Orion's Horsehead Nebula?

April 5, 2018

Two research teams used a map from NASA's Stratospheric Observatory for Infrared Astronomy, SOFIA, to uncover new findings about stars forming in Orion's iconic Horsehead Nebula. The map reveals vital details for getting ...

Stars vs. dust in the Carina Nebula

August 29, 2018

The Carina Nebula, one of the largest and brightest nebulae in the night sky, has been beautifully imaged by ESO's VISTA telescope at the Paranal Observatory in Chile. By observing in infrared light, VISTA has peered through ...

Two Hubble views of the same stellar nursery

April 19, 2018

These NASA Hubble Space Telescope images compare two diverse views of the roiling heart of a vast stellar nursery, known as the Lagoon Nebula. The images, one taken in visible and the other in infrared light, celebrate Hubble's ...

Image: Hidden secrets of a massive star-formation region

May 21, 2018

Stellar nurseries are cloudy and dusty places that shine brightly in infrared light. The G305 star-forming complex is no exception. It features a number of bright, intricate gas clouds heated by infant stars in their midst. ...

Recommended for you

Making stars when the universe was half its age

January 18, 2019

The universe is about 13.8 billion years old, and its stars are arguably its most momentous handiwork. Astronomers studying the intricacies of star formation across cosmic time are trying to understand whether stars and the ...

Saturn hasn't always had rings

January 17, 2019

One of the last acts of NASA's Cassini spacecraft before its death plunge into Saturn's hydrogen and helium atmosphere was to coast between the planet and its rings and let them tug it around, essentially acting as a gravity ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

FredJose
not rated yet Jan 11, 2019
But first: How do stars form naturalistically when there exists a pure and simple physical constraint called the Jeans Mass Limit which needs to be overcome first?
Since no purely naturalistic explanation could be found, the high priests of the bb model grasped at dark matter even though dark matter is completely un-characterized, unobserved and definitely not understood.
Yet they've already assigned it just the right properties to enable naturalistic star formation to occur all by it's merry self. Does that sound like SCIENCE to you? Or is it more akin to NON-SCIENCE?
Da Schneib
not rated yet Jan 11, 2019
Why we need the JWST.

I guess about as good an image as you can get from an airplane. Crappy compared to satellites. It does show stuff you can't see from ground-based telescopes, simply because of the water vapor in the atmosphere, but one couldn't call it "high resolution."
Da Schneib
not rated yet Jan 11, 2019
I can get better images from my small refractor in optical, like for example resolving the Trapezium (that bright spot in the middle of the picture published with this article. It's actually four visible stars, you can see this for yourself if you want to spend a couple thousand bucks and a year or two learning to use what you bought).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.