Dark Nebulae

Learn how a Star is Created in 30 Minutes!

This picture of a protostar in its accretion phase in the coldest, darkest, highest pressure of a molecular cloud figures large in understanding how stars form. Details of the image can be found in the posting on how gas bodies optically express themselves. Introduction This is the presentation that I gave at the 2026 Royal Astronomical Society of Canada‘s General Assembly this month (May 2026). I found that it summarizes the star formation process and how I interpret images fairly well and so I posted it here. I hope you enjoy. Thank-you Charles, for your kind introduction. My name is David Payne, I am a retired Professional Chemical Engineer, a member of the Victoria Centre of the RASC, and author

Gas Expression – Visual, Photographic, and Astrophysical

In this blog, we will discuss both how these gases turn up on our camera, and how astrophysics/spectroscopy identify and measure them. You will see that sometimes what we think we know is based on rock solid “DNA” evidence, while in many other cases, the evidence is purely circumstantial. For ease of explanation I will actually perform this task in reverse – like a mock trial – explaining what we believe the gases are and then the evidence that supports it. At the end, you may just interpret our astrophotographic images a little differently. In the vast expanse of our Milky Way, gases form the invisible backbone, shaping everything from star formation to galactic structure. They are the subject matter

A Galaxy of Dynamic Gases

The success of n-body numerical simulation to predict the motion of planets and stars cannot be denied. At the same time, the erroneous application of these model to intra-galactic objects and galaxies themselves have led to a popular narrative that is full of magic and other non-sense. In this ambitious posting, I have put together the astrophysical data in a different way – one that looks at objects from a more scientific and engineering point of view. This data has been used to show that the various objects in space should be considered as continuum bodies, rather than collections of particles. Classical physical laws and concepts are used to show how and why many of the phenomenon we see and

Thermodynamic Cloud Collapse & Me vs Gravity & Grok

Since I began working on this website, I have been using AI to fetch equations, data, and history. In general, I don’t bother discussing things much with AI, because typically AI relies on authority – number of journal articles, citations, simulations, status indicators, and other non-scientific bases to form its opinions. Me, on the other hand, I take the Richard Feynman philosophy that “Science is the belief in the ignorance of experts“. If AI believes you are straying from its narrative, it tries to “correct” you and actually let you know that what you are asking for is wrong. It finds something it agrees with, and then, tries to interject that it was at least somewhat right all along. It

More than Dust in the Wind

There is no deny that the dark nebula, LDN 534, makes an interesting target for astrophotography. It has all the earmarks of sky clouds being transformed by the wind. In fact it is likely a section of molecular cloud ripped out of the spiral arms, and being eroded by the winds of ISM. Unlike star fields that appear like foggy light that gets more disperse as concentration drops, the eroded molecular cloud seems to be much more wispy and reluctant to yield its integrity. Undoubtedly the hydrogen molecules do yield to the wind, disassociating to become atoms while the dust gets dispersed. We are lucky in this one, as a few stars make some nice blue reflections. In other cases, the eroded molecular cloud forms very coincidental shapes – included some naturally streamlined ones.

A Rotting Fish tells no tails

In this website’s second look at the Rotten Fish dark nebula, I wanted to bring home the concenpts involved in star nucleation. In case you were wondering, the answer is yes, star formation can happen in clouds not emitting Halpha light, even though we can certainly assiciate Haspha with star cluster / stellar nurseries. The answer lies in the mechanism of pressure buildup at points allowing diatomic molecular hydrogen and dust to nucleate a star. In both cases, dust provides the necessary cold temperature in addition to critical point temperature suppression. However, in the case of a dark cloud, the pressures required to nucleation is based on cloud turbulence alone, while stellar nursery clouds are aided in pressure build-up by stellar winds. It seems from images, that star formation in clouds is much more sporadic, while star clusters are more likely to be formed in stellar nurseries shining in Halpha light.

The Cave Nebula and Hydrogen’s Journey

One cannot understand the creation of stars from molecular hydrogen clouds any more than one can understand the weather here on earth without reference to thermodynamics. The weather is largely driven by water in gaseous (vapour), liquid (rain, clouds) and solid (snow, ice and ice crystals) forms. Knowing the pressures and temperatures at which these physical phase states occur is fundamental for both water in its role of creating weather, and for hydrogen in its role of creating both stars and the galaxy itself. Every atom and molecule of hydrogen must undergo and piecewise continuous journey through its phase/space – there is no leaping allowed, and the conditions must exist somewhere in a system for phase transitions to occur.
In our description of galaxies, we discuss the atomic and molecular phase states of hydrogen, but here we illustrate and explain the rest of the phase/state journey that hydrogen, at least at the nucleus of a star, must undergo to enable star formation. This is a journey from molecular gas all the way to becoming a hot, molten, liquid metal.

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