Astronomers Puzzled After Hubble View of Torrential Outflows From Infant Stars Blows Hole in Current Theories

Infant Stars in Orion

These four images taken by NASA’s Hubble Space Telescope reveal the chaotic birth of stars in the Orion complex, the nearest major star-forming region to Earth. The protostars were photographed in near-infrared light by Hubble’s Wide Field Camera 3. The images were taken on November 14, 2009, January 25, February 11, and August 11, 2010. Credit: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo)

Study Finds That Cavities Sculpted by Stellar Outflows Did Not Expand Over Time

Stars aren’t shy about announcing their births. As they are born from the collapse of giant clouds of hydrogen gas and begin to grow, they launch hurricane-like winds and spinning, lawn-sprinkler-style jets shooting off in opposite directions.

This action carves out huge cavities in the giant gas clouds. Astronomers thought these stellar temper tantrums would eventually clear out the surrounding gas cloud, halting the star’s growth. But in a comprehensive analysis of 304 fledgling stars in the Orion Complex, the nearest major star-forming region to Earth, researchers discovered that gas-clearing by a star’s outflow may not be as important in determining its final mass as conventional theories suggest. Their study was based on previously collected data from NASA’s Hubble and Spitzer space telescopes and the European Space Agency’s Herschel Space Telescope.

The study leaves astronomers still wondering why star formation is so inefficient. Only 30% of a hydrogen gas cloud’s initial mass winds up as a newborn star.

Though our galaxy is an immense city of at least 200 billion stars, the details of how they formed remain largely cloaked in mystery.

Scientists know that stars form from the collapse of huge hydrogen clouds that are squeezed under gravity to the point where nuclear fusion ignites. But only about 30 percent of the cloud’s initial mass winds up as a newborn star. Where does the rest of the hydrogen go during such a terribly inefficient process?

It has been assumed that a newly forming star blows off a lot of hot gas through light-saber-shaped outflowing jets and hurricane-like winds launched from the encircling disk by powerful magnetic fields. These fireworks should squelch further growth of the central star. But a new, comprehensive Hubble survey shows that this most common explanation doesn’t seem to work, leaving astronomers puzzled.

Researchers used data previously collected from NASA’s Hubble and Spitzer space telescopes and the European Space Agency’s Herschel Space Telescope to analyze 304 developing stars, called protostars, in the Orion Complex, the nearest major star-forming region to Earth. (Spitzer and Herschel are no longer operational.)

HOPS Sources in Orion

This ground-based image offers a wide view of the entire Orion cloud complex, the closest major star-forming region to Earth.
The red material is hydrogen gas ionized and heated by ultraviolet radiation from massive stars in Orion. The stars are forming in clouds of cold hydrogen gas that are either invisible or appear as dark regions in this image. The crescent shape is called Barnard’s Loop and partly wraps around the winter constellation figure of Orion the Hunter. The hunter’s belt is the diagonal chain of three stars at image center. His feet are the bright stars Saiph (bottom left) and Rigel (bottom right).
This landscape encompasses tens of thousands of newly forming stars bursting to life. Many are still encased in their natal cocoons of gas and dust and only seen in infrared light.
The undulating line of yellow dots, beginning at lower left, is a superimposed image of 304 nascent stars taken by NASA’s Hubble Space Telescope.
Researchers used NASA’s Hubble and Spitzer space telescopes and the European Space Agency’s Herschel Space Telescope to analyze how young stars’ powerful outflows carve out cavities in the vast gas clouds. The study is the largest-ever survey of developing stars.
Credit: Image courtesy of R. B. Andreo,; Data Overlay: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo)

In this largest-ever survey of nascent stars to date, researchers are finding that gas—clearing by a star’s outflow may not be as important in determining its final mass as conventional theories suggest. The researchers’ goal was to determine whether stellar outflows halt the infall of gas onto a star and stop it from growing.

Instead, they found that the cavities in the surrounding gas cloud sculpted by a forming star’s outflow did not grow regularly as they matured, as theories propose.

“In one stellar formation model, if you start out with a small cavity, as the protostar rapidly becomes more evolved, its outflow creates an ever-larger cavity until the surrounding gas is eventually blown away, leaving an isolated star,” explained lead researcher Nolan Habel of the University of Toledo in Ohio.

“Our observations indicate there is no progressive growth that we can find, so the cavities are not growing until they push out all of the mass in the cloud. So, there must be some other process going on that gets rid of the gas that doesn’t end up in the star.”

The team’s results will appear in an upcoming issue of The Astrophysical Journal.

A Star is Born

During a star’s relatively brief birthing stage, lasting only about 500,000 years, the star quickly bulks up on mass. What gets messy is that, as the star grows, it launches a wind, as well as a pair of spinning, lawn-sprinkler-style jets shooting off in opposite directions. These outflows begin to eat away at the surrounding cloud, creating cavities in the gas.

Popular theories predict that as the young star evolves and the outflows continue, the cavities grow wider until the entire gas cloud around the star is completely pushed away. With its gas tank empty, the star stops accreting mass – in other words, it stops growing.

Compass Image Infant Stars in Orion

These four images taken by NASA’s Hubble Space Telescope reveal the chaotic birth of stars in the Orion complex, the nearest major star-forming region to Earth. The protostars were photographed in near-infrared light by Hubble’s Wide Field Camera 3. Credit: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo)

To look for cavity growth, the researchers first sorted the protostars by age by analyzing Herschel and Spitzer data of each star’s light output. The protostars in the Hubble observations were also observed as part of the Herschel telescope’s Herschel Orion Protostar Survey.

Then the astronomers observed the cavities in near-infrared light with Hubble’s Near-infrared Camera and Multi-object Spectrometer and Wide Field Camera 3. The observations were taken between 2008 and 2017. Although the stars themselves are shrouded in dust, they emit powerful radiation which strikes the cavity walls and scatters off dust grains, illuminating the gaps in the gaseous envelopes in infrared light.

The Hubble images reveal the details of the cavities produced by protostars at various stages of evolution. Habel’s team used the images to measure the structures’ shapes and estimate the volumes of gas cleared out to form the cavities. From this analysis, they could estimate the amount of mass that had been cleared out by the stars’ outbursts.

“We find that at the end of the protostellar phase, where most of the gas has fallen from the surrounding cloud onto the star, a number of young stars still have fairly narrow cavities,” said team member Tom Megeath of the University of Toledo. “So, this picture that is still commonly held of what determines the mass of a star and what halts the infall of gas is that this growing outflow cavity scoops up all of the gas. This has been pretty fundamental to our idea of how star formation proceeds, but it just doesn’t seem to fit the data here.”

Future telescopes such as NASA’s upcoming James Webb Space Telescope will probe deeper into a protostar’s formation process. Webb spectroscopic observations will observe the inner regions of disks surrounding protostars in infrared light, looking for jets in the youngest sources. Webb also will help astronomers measure the accretion rate of material from the disk onto the star, and study how the inner disk is interacting with the outflow.

Reference: “An HST Survey of Protostellar Outflow Cavities: Does Feedback Clear Envelopes?” by Nolan M. Habel, S. Thomas Megeath, Joseph Jon Booker, William J. Fischer, Marina Kounkel, Charles Poteet, Elise Furlan, Amelia Stutz, P. Manoj, John J. Tobin, Zsofia Nagy, Riwaj Pokhrel and Dan Watson, 28 April 2021, The Astrophysical Journal.
DOI: 10.3847/1538-4357/abded8
arXiv: 2102.06717

16 Comments on "Astronomers Puzzled After Hubble View of Torrential Outflows From Infant Stars Blows Hole in Current Theories"

  1. Bibhutibhusanpatel | March 21, 2021 at 10:19 am | Reply

    Protostars or the newly born stars have a rato of mass 3:10 to
    the initial amount of mass of total hydrogen gas present before formation of stars. So here each star is in a state of equilibrium with rest of the original stars created by Supeŕ massive black hole(ofcouŕse other stars of same type or class formed befoe from hydrogen gas may have fixed at balanced equlibrìum position of force due to Gravity are present). In turn the Galaxy,Milkyway always so adjusted as to in permanent state of eqlibrium with other galaxies.So Space-Time Curvature remains intact, hence value of G ŕemains constant.The outflow of a neostar exerts a force of ìmpact on residùal 70٪ of gas suppliments required foŕce to keep the same at space.Magnetic disc shows to complet..the process of building star.

    • Torbjörn Larsson | March 22, 2021 at 2:09 pm | Reply

      Bibhutibhusanpatel, as I’ve seen before you describe at least part of the physics in an astute manner but perhaps through translation it comes out as a hard read (for me).

      The common central super massive black holes of galaxies seems to be present and regulate galaxy growth from the beginning, but that is not to say that they “create” the average star in a galxy as much as prevent them to form faster by heating up the galaxy gas to circulate away from the galaxy disk. (Seems that supermassive black hole massive accretion disks may be able to form stars, but those should be doomed to be shredded by the black hole eventually.)

      I *think* you mean to say that these dynamic – not static as your comment seem to suggest – equilibrium systems of mature isolated galaxies, that with gravity dominating should obey the virial theorem, show that the gravitational constant G is universal [ ]. Maybe they do, and it is of course easier to model cosmology if the average space curvature is zero (flat space], but that is due already to the universe being a general relativistic system [“Friedmann–Lemaître–Robertson–Walker metric”, Wikipedia].

      From Wikipedia:

      “This model is sometimes called the Standard Model of modern cosmology,[4] although such a description is also associated with the further developed Lambda-CDM model.”

      If you look up the “Solutions” part, you recognize our dear, old G constant in explicit use. So I would say that it is the cosmological applicability of general relativity that show it – against observation – to be a truly universal constant.

  2. Bibhutibhusanpatel | March 21, 2021 at 11:35 am | Reply

    Prrtostars or the newly born stars have mass ratio of 3:7 with total amount of the hydrogen gas present before formation start.This amount of mass ratio thus accounts for stability of the neostar at the position of space present in the Galaxy,Milkyway.The neostar is in equilibrium with all other stars created by the Supermassive black hole(ofcourse other stars of same type or class formed before may present also).The galaxy,milkyway is so in the permanent state of preexisting equilibrium with all other gaiaxies.So Space-Time Cùrvaturè remains intact.Hence value of G is constant.Here oùtflow from newly born star cast required impact to get generate force at certaìn average constant rate to fix the same at specific space.For a certain period of time this process occures, which is mentioned ad 500,000 years here.Magnetic disc complete the star building process.

  3. 500,000 years of a pair of jets spewing huge amounts of energy and particles into a steady state cavity. The cavity neither grows larger nor gains density during this developmental time.

    Where does the extra go if the jets are not clearing the envelope surrounding the cavity?
    Good question. The answer should be obvious once it is shown. But for now the hindsight is not here and the reason is not clear at all.

  4. Circulating dark matter appears to happen on a galactic and solar scale. The dark matter circulation would initially spray off like liquid poured on a spinning record as it moves outward gravity would cause it to curve up or down and back towards the star. Once this circulation is established it would be counter to the inflow due to gravity.

    • Torbjörn Larsson | March 22, 2021 at 2:22 pm | Reply

      Dark matter is, like normal matter, treated as “a perfect liqiuid” (gas) in the general relativistic Lambda-Cold Dark Matter model equations. But the ill understood dynamics makes it show up as clumps, perahsp from being attracted into galaxy wells of open, later dispersed star clusters (such as the Orion Complex may form) [ ].

      “Hunting for dark matter concentrations devoid of stars has proved challenging. The Hubble research team, however, used a technique in which they did not need to look for the gravitational influence of stars as tracers of dark matter. The team targeted eight powerful and distant cosmic “streetlights,” called quasars (regions around active black holes that emit enormous amounts of light). The astronomers measured how the light emitted by oxygen and neon gas orbiting each of the quasars’ black holes is warped by the gravity of a massive foreground galaxy, which is acting as a magnifying lens.

      Using this method, the team uncovered dark matter clumps along the telescope’s line of sight to the quasars, as well as in and around the intervening lensing galaxies. The dark matter concentrations detected by Hubble are 1/10,000th to 1/100,000th times the mass of the Milky Way’s dark matter halo. Many of these tiny groupings most likely do not contain even small galaxies, and therefore would have been impossible to detect by the traditional method of looking for embedded stars.”

      The average solar system volume contains just an average asteroid worth of drak matter, so its effects is insignificant on that scale. Dark matter is essential to form galaxies and other large star systems down to some large total mass, but presumably not at all to form individual stars.

      “Because we know the mass of the Milky Way, the relative densities of normal and dark matter, and we have simulations that tell us how the dark matter density ought to behave, we can come up with some very good estimates. When you do these calculations, you find that about 10^13 kg of dark matter ought to be felt by Earth’s orbit, while around 10^17 kg would be felt by a planet like Neptune.

      But these values are tiny compared to the other masses of consequence! The Sun has a mass of 2 × 10^30 k”

      [“Ask Ethan: If Dark Matter Is Everywhere, Why Haven’t We Detected It In Our Solar System?”, Forbes]

  5. This is pure crap we live in a plasma universe ruled by electricity and magnetism stats form from z pinches on burkland currents every new observation has a title similar to this. Because they are wrong at the foundations. Gravity relativity nuclear gavrituc stars are all BS red blue shift is age not distance when we looked at the sky we could not see thw gas and suat they are now seeing with the new tech we have and guess what we are findind this gas and dust in the same spots e here they predi Ted dark dukey to be. There is a crisis as big as the universe in the dogmatic BS of thw standard model. Boo boo to theoretical physicist and the astro scientist that perpetuate that bs

    • Torbjörn Larsson | March 22, 2021 at 2:26 pm | Reply

      Pseudoscience, as shown by what scientists actually see as described in the article, as well as the absence of evidence.

      For any opinion, the following applies: “That which can be asserted without evidence, can be dismissed without evidence.”

      For pseudoscience, it can further apply that we already know the facts – as here.

  6. Astronomers Puzzled? Well, they will remain puzzled as long as they ignore the true nature of reality, the electro magnetic forces pulsing through plasma. Their gravity centered theories are absurd and provide a poor explanatory model of the cosmos, as this, and many other “Puzzled” titled articles, imply.

    • Torbjörn Larsson | March 22, 2021 at 2:28 pm | Reply

      This is uninteresting (and in this case erroneous) pseudoscience, so my response to Sergo applies here as well.

  7. This site is click baity garbage news. If you want real, level headed science news look elsewhere.

    • Torbjörn Larsson | March 22, 2021 at 2:49 pm | Reply

      The Space Telescope Science Institute (STScI) is of course known for real, level headed science, which applies to this press release [ ].

      “The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST) and for the James Webb Space Telescope (JWST). STScI is located on the Johns Hopkins University Homewood Campus in Baltimore, Maryland and was established in 1981 as a community-based science center that is operated for NASA by the Association of Universities for Research in Astronomy (AURA).”

      I wouldn’t call a press release “news” for anyone besides the experts, but of course it can describe exciting new results on the expert level at times. It takes time and effort to be able to read science papers, more so for someone not expert in the area.

      That was the material and its source. So, can a non-level headed site present “real, level headed science” by mistake. Of course it can, and since this is not a press release aggregator like Phys Org say, there should also be selection bias in play. But SciTechDaily is founded by a science journalist and skeptic with the best intentions.

      “SciTechDaily offers the best intelligent, informed science and technology coverage and analysis you can find on a daily basis, sourcing a huge range of great writers and excellent research institutes. It was founded in 1998 by Vicki Hyde …”

      “In 2002, was selected as one of five final nominations in the Science Category for a Webby Award. The main award, decided by the International Academy of Digital Arts and Sciences. Ultimately, Becoming Human won the Science Webby and the NASA Earth Observatory won the People’s Voice award, but it was still an honor to be up for nomination competing with the likes of NASA.

      We continued to grow and in 2011 we had a major change in format and site design. Instead of being a daily updated digest of the most relevant science links (the New York Times and others referred to us as essentially a Drudge Report for science and technology), we began publishing science and technology articles directly. We continue our selective focus on the best science and technology breakthroughs, assuring great coverage of the most important science events and research. Instead of a single editor, we grew into a team of editors with the experience to meticulously select the most important and informative subjects for publication.

      Our stories are frequently republished and linked to throughout the web. Find us in Yahoo News, Fark, ArsTechnica, Futurism, and many other popular sites.

      Learn more about the scientists, researchers, and engineers that help make SciTechDaily a supreme source for science and technology news by reading about our Editorial Board.”

      And from her article on Wikipedia:

      “Vicki Cathryn Hyde MNZM (née Spong, born 1962) is a New Zealand science writer and editor, and former chair-entity of the New Zealand Skeptics.”

      So it is commercial site with an expertise in science.

      The only putative problem I can see is that Hyde founded the nominally “skeptic” NZ Skeptics to be non-skeptical against religion specifically, for reasons of her own (and they don’t seem to have changed that).* So beware of the superstitious bias – which often is called “being soft on religion”, or “having a belief in belief” – that may or may not be notable here as well, depending on how the nominally scientist populated Editorial Board works.

      *It makes the religious “agnostic” claim “religion is not testable unless the supporter makes a specific claim”, which of course is a specific claim in itself and moreover we know is wrong. The universe can arguably be shown to be an entirely natural system, based on observation, since 2018ish. Seems there io need for specific claims – it is a very general result – and as noted that specific claim of “no test” had no evidence in the first place.

  8. Torbjörn Larsson | March 22, 2021 at 1:36 pm | Reply

    Fantastic more detail in newer images of the Orion Nebula, and a hot new topic to boot! As stated in a review already 3 years ago:

    “Perhaps the simulations’ single biggest lesson so far is not that scientists need to revise their overarching theory of cosmology, but rather that problems lurk in their understanding of astrophysics at smaller scales. In particular, their theory of star formation comes up wanting, Springel says. To produce realistic galaxies, modelers must drastically reduce the rate at which clouds of gas form stars from what astrophysicists expect, he says. “Basically, the molecular clouds form stars 100 times slower than you’d think,” he says.”

    [ ]

    Here the paper summary ending adds:

    “Our findings indicate that outflow clearing is not the primary mechanism for the dissipation of the envelope during the Class I phase. It further suggests that clearing alone cannot explain the ∼ 30–40 % star formation efficiencies inferred from core mass functions.

    Current measurements of the amount of mass directly launched by protostar in winds or jets suggest that this additional factor is not sufficient. Measurements of the molecular gas with millimeter interferometry are needed to determine whether slower, higher density flows entrained by the outflows are responsible for the halting of infall/accretion and the ∼ 30–40 % star formation efficiencies. If they are not, mechanisms other than feedback may be required.”

    That is, they need better observations to eliminate possible molecular gas.

    Re millimeter interferometry:

    “Interferometry at millimeter wavelengths offers many unique scientific capabilities. … Most of the low order rotational (electric dipole) transitions of cosmically abundant molecules fall in the mm spectrum.”

    [“Millimeter Interferometry”
    Authors: Carilli, C. L., Carlstrom, J. E., & Holdaway, M. A.
    Journal: Synthesis Imaging in Radio Astronomy II, A Collection of Lectures from the Sixth NRAO/NMIMT Synthesis Imaging Summer School. Edited by G. B. Taylor, C. L. Carilli, and R. A. Perley. ASP Conference Series, Vol. 180, 1999, p. 565.]

  9. Marc Blackwell | March 22, 2021 at 8:18 pm | Reply

    I am not an astrophysicist. But it seems to me like this formation could be like an explosion first you have a pressure wave that forces everything out when the pressure stops and reverse as it sucks stuff back in that might be why the cloud does not continue to expand.

  10. Geez, all the blah blah blah talk here. All I care about is my pizza staying warm.


    Circulating dark matter changes the picture with respect to spikiness.

    Also if dark matter were to reside in a QL soup outside of spacetime a black hole and a GEODE could coexist.

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