Question How do stars form?

Apr 13, 2021
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Where can we see the birth of stars?

M87 vortex goes for about 100,000 light years. Along the length of the vortex we see millions of stars.

Through out our galaxy and other galaxies we see clusters of stars and some clusters having a million stars.

Why are their billion or so stars in the spiral arms of spiral galaxies.

Why are their billions of stars in elliptical galaxies and other form galaxies?
 
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"Where can we see the birth of stars?" A good question in my thinking is asked here. My answer, the most common locations are giant molecular gas clouds like M42 in Orion are tossed around in the literature and reports. However, *see* is the problem. No astronomers observe or *see* a gas cloud contradict into a ZAMS plot on the H-R diagram. Many different observations are compiled to interpret this so this is an interpretation, not *see* :).

However, are all these different observations compiled as clean a bill in science measurement like this report on measuring the distance to an asteroid? Example, AMATEUR ASTRONOMERS TEAM UP TO MEASURE DISTANCE TO A CLOSE-PASSING ASTEROID, https://skyandtelescope.org/observing/amateur-team-measures-distance-near-earth-asteroid/

My answer is no, the asteroid report and measurement is more certain science by the scientific method in my opinion. Likewise no one has observed a spiral galaxy regenerate and form new arms over billions of years, multiple rebirths of the spiral arms. So as I apply the standard of observation and *see* in the asteroid distance measurement to this thread, no one *sees* a star form like we can *see* the measurement for the distance to the asteroid :)
 
Cat answer in post #3 is the answer used in astronomy today. However, all origins science depends upon this principle assumed as true I cite here. Whether reporting how stars form from gas clouds or explaining how more than one billion years of strata are missing at Grand Canyon that is no longer visible today.

"Uniformitarianism, also known as the Doctrine of Uniformity or the Uniformitarian Principle, is the assumption that the same natural laws and processes that operate in our present-day scientific observations have always operated in the universe in the past and apply everywhere in the universe. It refers to invariance in the metaphysical principles underpinning science, such as the constancy of cause and effect throughout space-time, but has also been used to describe spatiotemporal invariance of physical laws. Though an unprovable postulate that cannot be verified using the scientific method, some consider that uniformitarianism should be a required first principle in scientific research. Other scientists disagree and consider that nature is not absolutely uniform, even though it does exhibit certain regularities."

I used MS BING search to find this. The asteroid observation and distance measurement cited in post #2, does not require Uniformitarianism to be true, operating over billions of years to see and make the measurement today. Origins science does.
 

Catastrophe

"There never was a good war, or a bad peace."
Rod, firstly, I said "simple answer". There may be some newer readers happy with this, for starters. I, and many others, greatly appreciate your in depth replies. :)

Regarding uniformitarianism, I believe the correct view is to temper this with a certain (variable) amount of catastrophism. Thus, there was considerable impacting roughly 4 billion years ago. S ince the Late Heavy Bombardment, but still impacts occur from dust upwards to quite small (depending on definition).

Late Heavy Bombardment - Wikipedia
https://en.wikipedia.org › wiki › Late_Heavy_Bombard...


The Late Heavy Bombardment (LHB), or lunar cataclysm, is a hypothesized event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago, ...
Evidence for a cataclysm · ‎Geological consequences on... · ‎Possible causes


Cat :)
 
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There have many theories over the last several hundred years for how stars might form. Kant promoted the idea that clouds would collapse and form them. Laplace first agreed using math but, IIRC, realized the math portion addressing conservation of angular momentum meant the spin rate for a proto star would be too fast to hold itself together. So other theories were more popular.

But, with better scopes, things like bipolar flows were observed, hinting of a way to dump that excess angular momentum. MHD models have also improved to the degree that support cloud collapse models.

Also, with IR scopes, the hypothesized accretion disks were found for protstars, furthering great support for today’s models.

Astronomer’s vast studies have brought us the IMF (Initial Mass Function). For a given mass of a cloud, the number of stars of different mass can be approximated.
 
Helio post #6 brings up some interesting points. However, using gas clouds collapsing slowly to form the stars does not answer some of the issues raised in post #1, like the many billions of stars we see today in the Milky Way. Example from post #1, "Why are their billion or so stars in the spiral arms of spiral galaxies."

None of what Helio presents answer this question. There is a limited number of molecular clouds documented in the galaxy today, this source shows 8107 with a total mass estimated at 1.2 x 10^9 solar masses. https://heasarc.gsfc.nasa.gov/W3Browse/all/mwmc.html#:~:text=MWMC - Milky Way Molecular Clouds from CO,CO emission observed within b +/- 5 deg.

If we assume that the 8107 clouds can be turned into 1.2x10^9 stars, that assumes 100% star formation efficiency in each gas cloud documented. Do observations show this? Not in my opinion. Then there is the issue of time constraints on how long molecular gas clouds or giant molecular gas clouds like M42 exist for? Some reports I have indicate for many, perhaps 10-30 million years. This time scale suggests that all 8107 clouds documented in my reference are all, very young and recent origin.

Intensive studies are done to show the molecular clouds form new stars and can explain all that we see but this is limited science too. A model for the formation of stellar associations and clusters from giant molecular clouds - NASA/ADS (harvard.edu)

The IMF can be used for a specific gas cloud studied but lacks the ability to define precise numbers and explain the very large quantity of stars observed and documented today using the very small number of molecular clouds documented that we do see. Thus my post #2, the science of measuring the asteroid parallax and distance is more secure than the science claiming to explain how all the stars we see today in the galaxy formed.
 
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M87 vortex goes for about 100,000 light years. Along the length of the vortex we see millions of stars.
I don't know what you mean by vortex?

M87 is an elliptical galaxy. They are likely formed over vast amounts of time as they absorb other galaxies that got too close. There are over 1 trillion stars in this galaxy. As smaller galaxies collide with it, the large gravitational stresses shred the grouping of the stars and distribute them, eventually, in a spherical pattern. [The stars aren't shredded themselves, unless they get very close to the central BH.]

The MW has a lot of gas left to form more stars, but most of the gas may have already collapsed into the 200 billion + stars in our galaxy. There is still a lot of gas not found in the limited number of clouds found. Astronomers can't see them all since it is so hard to study the other side of the galaxy since one must look through all the mess between us and the other side.

If we assume that the 8107 clouds can be turned into 1.2x10^9 stars, that assumes 100% star formation efficiency in each gas cloud documented.
The average efficiency of cloud conversion to stars is about 2%, IIRC. One would need to know the masses of all those clouds, extrapolate for areas we can't survey, then add for interstellar gas, if we want to know the max. no. of stars that could be formed. Rod, could easily be in the ballpark with his estimates.

Some reports I have indicate for many, perhaps 10-30 million years. This time scale suggests that all 8107 clouds documented in my reference are all, very young and recent origin.
Yes. That seems likely.

Here is a paper that addresses this along with how clouds may form over time, and how they decay.

The IMF can be used for a specific gas cloud studied but lacks the ability to define precise numbers and explain the very large quantity of stars observed and documented today using the very small number of molecular clouds documented that we do see. Thus my post #2, the science of measuring the asteroid parallax and distance is more secure than the science claiming to explain how all the stars we see today in the galaxy formed.
Okay. My parallax observations with my eyes determining the distance to the red apple on the table is probably superior still. And I know its color, too! The modeling of complex processes at vast distances is part of the fun in astronomy. Better telescopes almost always come along to refute one model in favor of another. But when there are many lines of evidence that point at one and only one possibility, then we have a very strong model.
 
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Star formation from condensed clouds can produce stars.
This process is limited,
How do we form millions of stars in one cluster?
How do spiral arms have millions or billions in one arm?
To understand this you need to understand a mimic black hole, this is a black hole without a singularity.
Our Millyway has many such Mblackholes.
A main property is a dipolar electromagnetic vector force field. From the core expelling droplets of high condensed matter (10*17 to over 10*25) these droplets form the seeds of stars, Do the maths expand the droplets.
10 mm expand by 10*25 away from the confinement of the core.
M87 vortex is part of a dipolar, its vortex is about 100,000 light years and along the vortex we see star formation into the millions, look at the images, its amazing force has created a monster elliptical galaxy compared to spiral galaxies having 2 or 4 spirals ejected from the core of the galaxy,
There are thousands of observations of different galaxy formation.
Given that the universe and the parts within have an infinite time to merge and transform from one state to another,
 
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Food for thought
Astrophysics > Astrophysics of Galaxies
[Submitted on 25 Feb 2022]
Cluster Formation in GGD12-15: Infall Motion with Rotation of the Natal Clump
Tomomi Shimoikura, Kazuhito Dobashi, Naomi Hirano, Fumitaka Nakamura, Tomoya Hirota, Tomoaki Matsumoto, Kotomi Taniguchi, Yoshito Shimajiri
We report results of observations of the GGD12-15 region, where cluster formation is actively taking place, using various molecular emission lines. The C18O (J= 1-0) emission line reveals a massive clump in the region with a mass of ~2800 Mo distributed over ~2 pc. The distribution of the C18O(J= 3-2) emission is similar to that of a star cluster forming therein, with an elliptical shape of ~1 pc in size. A bipolar molecular outflow driven by IRS 9Mc, a constituent star of the cluster, is blowing in a direction perpendicular to the elongated C18O (J= 3-2) distribution, covering the entire clump. There is a massive core with a radius of 0.3 pc and a mass of 530 Mo in the center of the clump. There are two velocity components around the core, which are prominent in a position-velocity (PV) diagram along the major axis of the clump. In addition, a PV diagram along the minor axis of the clump, which is parallel to the outflow, shows a velocity gradient opposite to that of the outflow. The velocity structure strongly indicates the infalling motion of the clump. Comparison of the observational data with a simple model of infalling oblate clumps indicates that the clump is undergoing gravitational contraction with rotation.
Comments:12 figures
Subjects:Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as:arXiv:2202.12492 [astro-ph.GA]
(or arXiv:2202.12492v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2202.12492
Focus to learn more
Journal reference:The Astrophysical Journal, 2022

Is this science correct.
Can we question? Yes we can
 
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OK sorry for posting papers. But learning cutting edge info is the path to maybe understanding more than we know.

Astrophysics > Astrophysics of Galaxies
[Submitted on 2 Nov 2021]
The MURALES survey. V. Jet-induced star formation in 3C 277.3 (Coma A)
A. Capetti (1)B. Balmaverde (1)C. Tadhunter (2)A. Marconi (3,4)G. Venturi (14,4)M. Chiaberge (5,6)R.D. Baldi (7)S. Baum (8)R. Gilli (9)P. Grandi (9)Eileen T. Meyer (10)G. Miley (11)C. O'Dea (8)W. Sparks (12)E. Torresi (8)G. Tremblay (13) ((1) INAF - Osservatorio Astrofisico di Torino, Pino Torinese, Italy (2) Department of Physics & Astronomy, University of Sheffield, Sheffield, UK (3) Dipartimento di Fisica e Astronomia, Università di Firenze, Sesto Fiorentino, Italy (4) INAF - Osservatorio Astrofisico di Arcetri, Firenze, Italy (5) Space Telescope Science Institute, Baltimore, MD, USA (6) Johns Hopkins University, Baltimore, MD, USA (7) INAF- Istituto di Radioastronomia, Bologna, Italy (8) Department of Physics and Astronomy, University of Manitoba, Winnipeg, (9) INAF - Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Bologna, Italy Canada (10) University of Maryland Baltimore County, Baltimore, MD, USA (11) Leiden Observatory, Leiden University, Leiden, the Netherlands, USA (12) SETI Institute, Mountain View, CA (13) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (14) Instituto de Astrofisica, Facultad de Física, Pontificia Universidad Católica de Chile, Santiago, Chile)
We present observations obtained with the VLT/MUSE optical integral field spectrograph of the radio source 3C277.3, located at a redshift of 0.085 and associated with the galaxy Coma A. An emission line region fully enshrouds the double-lobed radio source, which is ~60 kpc x 90 kpc in size. Based on the emission line ratios, we identified five compact knots in which the gas ionization is powered by young stars located as far as ~60 kpc from the host. The emission line filaments surrounding the radio emission are compatible with ionization from fast shocks (with a velocity of 350-500 km/s), but a contribution from star formation occurring at the edges of the radio source is likely. Coma A might be a unique example in the local Universe in which the expanding outflow triggers star formation throughout the whole radio source.
Comments:Pre-proofs version - Accepted for publication in A&A
Subjects:Astrophysics of Galaxies (astro-ph.GA)
Cite as:arXiv:2111.01615 [astro-ph.GA]
(or arXiv:2111.01615v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2111.01615
Focus to learn more
Related DOI:https://doi.org/10.1051/0004-6361/202141965
Focus to learn more
 
The limited number of observable GMC and molecular gas clouds in the MW today is a problem showing the answers provided in various posts here are not a * very strong model*, post # 8 by Helio. Within 2 kpc of the Sun, there is 72 GMCs documented today, not an abundant number that explains so many stars we see within 2 kpc of the Sun. Ref - Bird's eye view of molecular clouds in the Milky Way. I. Column density and star formation from sub-parsec to kiloparsec scales, https://ui.adsabs.harvard.edu/abs/2021A&A...653A..63S/abstract, Sep-2021. "...Results: We present a census of the molecular clouds within 2 kpc distance, including 72 clouds and YSO counts for 44 of them."

Another report shows 5469 clouds documented (these may not all be in the MW), https://arxiv.org/pdf/1608.05415.pdf My note. This NASA ADS Abstract indicates GMCs may have a 27 Myr lifetime - https://iopscience.iop.org/article/10.1088/0004-637X/729/2/133/pdf, 10-March-2011. "... We show that the lifetimes of GMCs at the mean mass found in our sample is 27 ± 12 Myr, a bit less than three free-fall times." "Recent work using the NANTEN telescope has determined that GMCs in the Large Magellanic Cloud have a lifetime of 20–30 Myr (Kawamura et al. 2009; Fukui & Kawamura 2010), about 3τff…" This NASA ADS Abstract reports 5469 GMC in a new catalogue, https://arxiv.org/pdf/1608.05415.pdf, 09-Sep-2016.

It is apparent that the current population of gas clouds documented for the Milky Way does not explain the myriad stars documented in the MW and Harry Costas questions at least to me, move in that direction. MS BING reports estimates range 100 to 400 billion stars for the MW, Helio uses 200 billion in post #8. Other reports show short lifetimes for these gas clouds used to explain star formation and the many stars seen in the MW today. Ref - The exciting lives of giant molecular clouds, https://ui.adsabs.harvard.edu/abs/2013MNRAS.432..653D/abstract, March-2013. "We present a detailed study of the evolution of giant molecular clouds (GMCs) in a galactic disc simulation. We follow individual GMCs (defined in our simulations by a total column density criterion), including their level of star formation, from their formation to dispersal. We find the evolution of GMCs is highly complex, and GMCs cannot be considered as isolated objects. GMCs often form from a combination of smaller clouds and ambient interstellar medium (ISM), and similarly disperse by splitting into a number of smaller clouds and ambient ISM. However some clouds emerge as the result of the disruption of a more massive GMC, rather than from the assembly of smaller clouds. Likewise in some cases, clouds accrete on to more massive clouds rather than disperse. Because of the difficulty of determining a precursor or successor of a given GMC, determining GMC histories and lifetimes is highly non-trivial. Using a definition relating to the continuous evolution of a cloud, we obtain lifetimes typically of 4-25 Myr for >10^5 M⊙ GMCs, over which time the star formation efficiency is about 1 per cent."

Even if we use an infinite age for the MW galaxy or a 13 billion years old age, GMCs and various documented molecular gas clouds seen today as the source for star formation in the MW, is insufficient to explain the origin of the myriad stars we see today, most without any gas clouds around them. The present population of molecular gas clouds in the MW are all very young compared to the age of the solar system using meteorite dating as an example. Within 2 kpc of the Sun, perhaps 72 are documented. The only way for a *very strong model* to emerge here is to assume multiple cycles of regeneration of spiral arms in the MW and multiple cyclic regeneration of GMCS for example. This postulate cannot be verified as true by the scientific method like the asteroid parallax and distance can I cited in my post #2.
 
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Harry Costas in post #9 asked, "How do we form millions of stars in one cluster?" My observation. This looks like how globular clusters form and the Milky Way contains at least 150 or so documented. One of my favorite to look at with my 10-inch telescope is M13 in Hercules.

Gravitational waves as a probe of globular cluster formation and evolution - NASA/ADS (harvard.edu) , Sep-2021. "Globular cluster formation is a long-standing mystery in astrophysics, with multiple competing theories describing when and how globular clusters formed."

Setting aside any concern over dating their ages, just explaining how a gas cloud or multiple gas clouds collapse to form 150 or more GCs in the MW is a challenge.
 
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Gravitational waves as a probe of globular cluster formation and evolution - NASA/ADS (harvard.edu) ,

The above paper assumes a start to the universe.
Since we cannot prove that theory.
We can look at the physics of how matter transforms from one state to another.
How do we explain how stars form without actually seeing their birth.
Yes stars may form from clouds condensing and compacting. What goes on in this compaction is most interesting.
As matter is compacted we can estimate normal matter can be compacted to 10 ^ 5.
FURTHER compaction is when the atoms photo disintegrate to Neutrons and Protons this compaction approach 10^ 17.
Further compaction occurs when Protons gain an electron to form Neutrons.
Oops i may have skipped a step.
No matter.
We have a Neutron Star. Compaction 10 ^ 17
Do we stop here?
Neutrons are made up of Quarks.
With further compaction and confinement, Quarks are free to move and be further compacted to 10^25. Found in the core of Neutron Stars.
Quarks are made of partonic matter and again compact approaching 10^30
Partonic matter breaks down to Axion Gluon Matter found in the cores of super Black Holes.
All the above matter have a property being dipolar. This property expels matter.
Droplets of this matter maybe able to seed stars.
The Big Bang Theory relies on this property. Forming stars and galaxies.
 
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Just my thinking, anytime astronomy invokes multiple generations of gas clouds forming and reforming to explain stars, clusters, and globular clusters, falls outside the scientific method to verify as true. There are many reports on the how to explain the origin of globular clusters, GCs.

Example, "A new computer model explores star formation and uncovered that globular clusters initially
formed with many more massive stars than in clusters observed today. "ScienceDaily (May
11, 2012)", How Nature Shapes the Birth of Stars, How nature shapes the birth of stars -- ScienceDaily
May-2021.

"A new computer model suggests globular clusters (GC) formed from galaxy collisions
including the nearly 200 in the Milky Way. This model shows many small clusters of stars
do not form but only the larger clusters remain after galaxy collisions which should take place
some 11-12 billion years ago in the big bang model.", Globular Clusters: Survivors of a 13-Billion-Year-Old Massacre,
Globular clusters: Survivors of a 13-billion-year-old massacre -- ScienceDaily , Feb-2012

The Formation of Globular Clusters as a Case of Overcooling, https://ui.adsabs.harvard.edu/abs/2022arXiv220303002R/abstract, March-2022.

“3 WHERE DID GLOBULAR CLUSTERS FORM? The GC with the most complex display of multiple populations is undoubtedly ω Centauri, which hosts at least 15 distinct stellar populations (Bellini et al. 2017). Though at that time such complexity was not known yet, Bekki & Freeman (2003) proposed that ω Cen was the remnant nuclear cluster of a now dissolved dwarf galaxy. We now wish to endorse an Ansatz such that not just ω Cen, but virtually all GCs formed inside dwarf galaxies (as first proposed by Searle & Zinn 1978), perhaps with the exception of the more metal rich ones. Indeed, the association of GCs with dwarf galaxies (as in the case of M54 and Sagittarius) and with Gaia streams is now being widely pursued (e.g., Massari, Koppelman & Helmi 2019). On the other hand, even the most metal poor GCs had to form in an environment in which the metallicity had reached about 1/100 solar, as expected for dwarf galaxies at over 12.5 Gyr lookback time, or z>∼ 3. In this picture GCs did not hurry to separate themselves from the womb where they formed. This may have taken several Gyr to do so. While waiting for the Galaxy to grow, young GCs were still immersed in the dense gas of the host dwarf that worked as a tamper holding the stellar ejecta within the new born cluster and possibly feeding it with stellar ejecta from stars in the dwarf itself. In any event, GCs are not pristine, though at least the metal poor largely predate the Galaxy. Often GCs are thought as having been accreted by the Galaxy, as if the Galaxy was already in place and the GCs arrived later, whereas it may well be that the actual late-comer is the bulk of the Galaxy itself, that was slowly built up by inflowing gas streams as currently understood (Dekel et al. 2009). Thus, as the Galaxy grew up, most dwarfs, but not all, have been tidally destroyed, then releasing their GCs. GCs are extremely compact objects, with density of the order of ∼ 10^7 particles cm^−1 (now all in stars), i.e., many thousand times that of typical molecular clouds in today’s Milky Way. Runaway gas cooling and gravitational collapse must have occurred to form them, but it is less clear how gas was squeezed to such high densities before forming stars. On the other hand, besides being very dense, GCs are also extremely slow rotators (Sollima, Baumgardt & Hilker 2019). It is possible that GCs can only form in deep local minima of the potential well created by the collapse of giant molecular clouds and in minima of the inter stellar medium (ISM) vorticity, which may explain why (thin) disk GCs do not exist. Otherwise, a mechanism should be invented as to remove angular momentum with extremely high efficiency from giant molecular clouds.”

It is clear from many papers published that showing how GCs formed is still very much, a work in progress :) When I view M42 using my 10-inch telescope and M13, I ponder issues like this :)

So, these papers show GCs could form by galaxy collisions and mergers, very massive stars not seen today in the GCs, and giant gas clouds assumed to exist but still difficult to show how these form GCs because of density issues. All of these mechanisms cannot be seen when examining the 150 or more GCs in the MW today or other star clusters, e.g. M45 in Taurus.
 
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Space.com just published this brief and interesting view on GCs and their formation. Very timely here :)
 
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Condensed Matter > Quantum Gases
[Submitted on 8 Sep 2021 (v1), last revised 14 Sep 2021 (this version, v3)]
Phonon Stability of Quantum Droplets in a dipolar Bose gases
Fan Zhang, Lan Yin
Stabilized by quantum fluctuations, dipolar Bose-Einstein condensates can form self-bound liquidlike droplets in the mean-field unstable regime. However in the Bogoliubov theory, some phonon energies are imaginary in the long-wavelength limit, implying dynamical instability of this system. A similar instability appears in the Bogoliubov theory of a binary quantum droplet, and is removed due to higher-order quantum fluctuations as shown recently [1]. In this work, we study the phonon energy of a dipolar quantum droplet in the Beliaev formalism, and find that quantum fluctuations can enhance the phonon stability. We obtain the anisotropic sound velocity which can be tested in experiment.
Subjects:Quantum Gases (cond-mat.quant-gas)
Cite as:arXiv:2109.03599 [cond-mat.quant-gas]
(or arXiv:2109.03599v3 [cond-mat.quant-gas] for this version)
https://doi.org/10.48550/arXiv.2109.03599
Focus to learn m

M87 dipolar jets Are about 100,000 light years.
The condensed droplets released from the core which is estimated to be over 10^25 compaction, may probably seed stars. We observe along the jet clusters of stars, these clusters will in time form part of the elliptical galaxy formation.
M87 is the centre of our local group of galaxies being over 200 .
M87 core is about 10 billion solar mass.
 
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Condensed Matter > Quantum Gases
[Submitted on 11 Nov 2021 (v1), last revised 15 Nov 2021 (this version, v2)]
Self-bound dipolar droplets and supersolids in molecular Bose-Einstein condensates
Matthias Schmidt, Lucas Lassablière, Goulven Quéméner, Tim Langen
We numerically study the many-body physics of molecular Bose-Einstein condensates with strong dipole-dipole interactions. We observe the formation of self-bound droplets, and explore phase diagrams that feature a variety of exotic supersolid states. In all of these cases, the large and tunable molecular dipole moments enable the study of unexplored regimes and phenomena, including liquid-like density saturation and universal stability scaling laws for droplets, as well as pattern formation and the limits of droplet supersolidity. We discuss a realistic experimental approach to realize both the required collisional stability of the molecular gases and the independent tunability of their contact and dipolar interaction strengths. Our work provides both a blueprint and a benchmark for near-future experiments with bulk molecular Bose-Einstein condensates.
Subjects:Quantum Gases (cond-mat.quant-gas); Atomic Physics (physics.atom-ph)
Cite as:arXiv:2111.06187 [cond-mat.quant-gas]
(or arXiv:2111.06187v2 [cond-mat.quant-gas] for this version)
https://doi.org/10.48550/arXiv.2111.06187
Focus to learn more

The idea of dipolar condensates has been discussed over decades.
Dirac in the words of Albert Einstein was one of the greatest scientists, in 1926 he gave as information On the DIRAC spinor describing all fundamental particle fermions including electrons and quarks, that would aid us in understanding condensates.
 

Catastrophe

"There never was a good war, or a bad peace."
OK, OP asked How do stars form.
Not all stars, but stars in general I assumed.
I suggested:
"Simple answer. By the action of gravity in random concentrations of matter throughout space."

May we ask OP what was the motivation of his question, and has it been answered? Did he intend to ask about the formation of all stars?

Cat :)
 
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Yep stars can form within the galaxy envelope.
The process of compaction is very similar.
The type of core formed will determine the life of the star.
 
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Globular clusters: Survivors of a 13-billion-year-old massacre -- ScienceDaily , Feb-2012

The above paper assumes that the universe is just over 13 billion years.
That the clusters having a million stars are the remains of the Big Bang,
With limited maths, how long will it take to form one billion galaxies let along having billions of stars in each galaxy.
How can we observe deep field images over 14 billion light years in what ever direction you choose and in an area of a rice seed over 5000 galaxies in various stages as we observe in the near.

We have in our hands the tools and the mind set to observe and formulate much more and not limited.
We are at the steps of much more.
 
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Quark Matter Droplet Formation in Neutron Stars
H. Heiselberg (Nordita, Copenhagen)
The formation rate of quark matter droplets in neutron stars is calculated from a combination of bubble formation rates in cold degenerate and high temperature matter. Nuclear matter calculations of the viscosity and thermal conductivity are applied. Results show that droplets form only in the core of neutron stars shortly after supernova collapse, where pressures and temperatures are high, and for sufficiently small interface tension between nuclear and quark matter. Coulomb energies hinder formation of large droplets whereas the presence of strange hadrons in nuclear matter increase the droplet formation rate.
The paper above was written over 25 years ago.
Quark matter droplets formed in the cores of Neutron stars.
Imagine what can happen in the cores of supermassive cores like M87 contains over 5 billion solar masses. Now imagine these droplets ejected from the core and are expelled along the dipolar jets that go for 100,000 light years.
These droplets are responsible for the formation of billions of stars and clusters of stars.

The Big Bang Nucleosynthesis relies on this method forming the universe as we see it.
The question is, how did over a trillion galaxies form within a short period of time, 14 billions years.
 
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Which method produces more Stars.
I would suggest that Condensates are responsible for most star seeding.
The ongoing processes of transformation, merging, cloud collapses etc need to be investigated.
 

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