Televue 127is; AP 1100GTO AE; QHY 600M, - Baader L,R,G,B filters.
L:  (220x 150s 61 Bin 1, Gain 26); R,G,B:  (105,107,103 x 180s, Bin 1, Gain 26)
Total integration time = 24.9 hrs (Aug 28-31, 2024) Maple Bay, BC

Although the same subject as a recent image post, this is actually a new image taken with my Televue 127is telescope, and processed to highlight the eddies and turbulence that exists within the molecular cloud.  In this case, the primary source of mechanical energy likely arises from the apparent flow of ultra low density ISM around and past the molecular cloud, that is mainly visible through reflection from the stars in the foreground and backlit by background stars.

Turbulence, of over multiple orders of magnitude spacial scales, generating angular and linear momentum of materials with widely different densities, viscosities, thermal and electrical conductivities, magnetic dipoles and other properties set up a complex dynamic system.  Collisions between different materials within the cloud likely also develop electrical charges that also contribute to the chaotic behavior that takes place – full of strange attractors and Lorenz type behavior.  It is well beyond our computer’s ability to simulate such dynamics on a fundamental basis, but it has been demonstrated that if sufficient turbulent behavior induced by, in this case, the flow of ISM past the molecular cloud, can readily lead to density waves that put hydrogen in a state where it can condense.  The energy, in this current case of a dark nebula, is being transferred from outside the molecular cloud to compress the gases and dust within.  The energy gets transformed into waste (low temperature) heat that is emitted to deep space by the dust.  The system is far from equilibrium and is actually star building (or at least a protostar nucleating) machine.  It has been my experience through imaging of both nebulae and galaxies that regions molecular cloud turbulence are the most likely places to find stellar nurseries, as is suggested by the emergence of young stellar objects in this “fish”.

High dust concentrations are required to dissipate the waste heat of the compression and viscous work done on the cloud, In addition dust needs shed the enthalpies of both vapourization and spin isomerization liberated by condensing hydrogen.  The dust needs to be able to both emit via long waves and readily allow for the thermal transfer of heat from the hydrogen to the dust.  This means that both high dust concentrations and hydrogen densities all at a low temperature need to occur at the same location.  It may be rare for all three conditions to exist at the same location within a dark molecular cloud, so proto-star formation rate is likely to be slow.  However, it indeed occurs as many, otherwise spurious, long wave emitters have been located within the molecular cloud indicated where heat is being shed, and JWST with its ability to peer deeper into the clouds is finding more protostars that originally believed.

It would be a great oversimplification to state that the hydrogen simply condenses under gravity to form a protostar nucleus, just as it is an oversimplification to say that planets or comets simply condense to their forms.  For example, a comet is likely a result of dust flocculated by through collisions and held together by frozen water, CO2, ammonia, methane, and cyano-hydrocarbons – relatively heavy molecules long after hydrogen and helium has left the local scene and temperatures have cooled.  The core of Saturn is also currently believed to a mixture of dust (and larger non-volatile material) as well as likely super-critical volatile components.  I believe understanding planet formation principles can yield a lot of insight into protostar formation (at least population I stars).

Nature has a lot of tricks up its sleave that she can bring to bear on the situation to help protostar formation along its way – including the chemistry of the dog’s breakfast of volatile and non-volatile materials with a cloud, the surface chemistry of both (true) metallic and non-metallic dust, the co-solubility in multiple phases of many of these materials combined with the outrageously peculiarity of hydrogen molecules themselves. 

Condensation likely first takes place of the dust or heavier molecular particles themselves at nucleation points – points where there is magnetic polarity, possible charge, or even mechanical stress where van der Waal attractive forces are enhanced.  In this manner, the surface of dust can act as catalysts to condensation – providing both a heat sink and a strong attractive force to hydrogen.

During the manufacture of liquified hydrogen (at much higher T and P) a metal surface, or carbonaceous material is used to both nucleate condensation and transfer the heat of condensation away.  Using this method, only a few millimetres of hydrogen condensation on the metal can be tolerated before heat transfer through the hydrogen can no longer keep up with both the latent heat of condensation in addition to heat generated through proton spin isomerization when H2 condenses. 

Perhaps, hydrogen does not so much “condense” on the dust, but might be better described as adsorption – but this is much the same thing.  In either case,  Van der Waal forces described as either condensation or adsorption are what hold molecules together.  Indeed, parts the surface of dust likely exhibit stronger van der Waal forces than inter molecular hydrogen, to a point that any condensation likely first occurs where these forces are strongest – on the surface of dust.  But hydrogen has another ace up its sleeve - the ability to form a much stronger connection with any electro-phyllic atoms, such as oxygen, nitrogen, or florine. 

This special bond that occurs between a hydrogen atom and electro-phyllic atoms is confusingly called a “hydrogen bond”, but is actually different from the covalent bond that holds the hydrogen molecule together but is very much stronger than normal van der Waal forces.  Hydrogen bonds are responsible for water having a much elevated melting and boiling point temperatures than its low molecular weight indicates as hydrogen in a water molecule is highly attracted to the oxygen in another.  This “super-power” of hydrogen is responsible for life as we know it, and why the universe exists as it is.  Within a molecular cloud there is also plentiful carbon monoxide with which hydrogen gas can form “hydrogen bonds” which can cause a mixture of CO and hydrogen to condense together at a much higher temperature and pressure as a solution.  Hydrogen will also dissolve into the myriad of hydrocarbons and inorganic materials that exist within the molecular cloud.  Any solutions that do condense or adsorb onto dust will also attract hydrogen as a second layer, likely making a colloidal suspension out of the dust particles themselves.

Such suspensions of dust will inevitably bump into one another and possibly stick together to form clumps – and a number of forces are likely responsible for this including magnetic, electrostatic, and zeta-potential.  Like a comet, it is this condensed material that ultimately forms the glue that holds the material together.  At this point, the clumps are likely made of the finest of dust in a bid to keep the heat transfer between condensing material and the dust high by presenting a large area to volume ratio.  The process of dust forming clumps is likely best described as flocculation.  As the clumps get larger and larger, like a frog in a warming pot of water, gravity slowly begins to exert an influence – at least within the clump itself.  Pressure begins to increase within the condensed material as it is squeezed by additional material being added around it through additional condensation and flocculation.  It is important to the embryonic star at this stage, however, that heat transfer can keep the temperature low, as vapourization at this stage will destroy the structure.  In addition, condensation must continue to occur on the surface so that it maintains a continuous phase from the centre to the outside to establish hydrodynamic equilibrium and build phase pressure.  Clumps themselves collide to form larger ones, provided that the energy released upon collision is small.

Eventually, as the floc’d material gets large enough and its accompanying gravity acceleration becomes large enough, it can attract hydrogen molecules directly to add to its mass.  This process must occur very gradually because it will be accompanies with a lot of heat (due to Joule Thomson compression and viscous shearing), and eventually overwhelm the condensed material’s ability to shed it via long-wave radiation.  The mass must be large enough so that the pressure can keep the now warming condensate above its critical pressure – again to avoid revaporization and disintegration of the nucleated protostar.  My back of the envelope calculations suggest that the  diameter of the embryonic mass need to be over 10 - 100 km in radius (depending upon dust/hydrogen ratio) before its can withstand any appreciable temperature  increase.

At this point I am sure I have left out some critical details, and likely gotten wrong on some other details, but it is the most plausible route to star nucleation that I can come up with.  At least I believe it to be must more plausible than the “spontaneous gravity collapse” that many of us have been taught.  Gases simply don’t spontaneously compress themselves under gravity alone, or at least I have not seen it occur myself.  If you think this story that I have presented fantastical story, then I would love to hear your comments and corrections.  However, I will be presenting an even more fantastical story when I describe how a star accumulates its mass and eventually ignites  - along with a future image – so if you enjoyed this, then stay tuned...