Stars are born – Have a Cigar

Stars are born – Have a Cigar

In an everyday spiral galaxy (ho hum?), every effort is made by the galaxy itself to minimize the amount of energy wasted on forming turbulence of dust and hydrogen. As a result, areas of intense star formation in a regular spiral is usually restricted to a discrete points along the spiral arms where ISM and molecular cloud rub against each other to create the turbulence. These limited areas of star formation are seen as patches of bright red Halpha emissions. In this image of the Cigar Galaxy, it is evident that something has thrown “a wrench/spanner into the works” and created a hell of lot of turbulence, resulting in a fireworks display of red Halpha. When this occurs, stars are created at a very high rate and we reclassify such galaxies as “starburst” glaxies and the Cigar is one of them. Still, the original stars and dust lanes of this once regular spiral can be made out.

The Cave Nebula and Hydrogen’s Journey

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.

Swirls, Eddies, and Star Nucleation in Molecular Clouds

Swirls, Eddies, and Star Nucleation in Molecular Clouds

The popular notion that stars are created by the spontaneous, adiabatic collapse of molecular clouds is challenged. Instead, a more physically realistic model of protostar nucleation through hydrogen/dust condensation is proposed here (and in other postings) on this website) as well as by many other astronomers and astrophyscists elsewhere. Thermodynamics dictate that such condensation requires relatively cold and places within the cloud enable such condensation coupled with possible dew/sublimation point elevation. The high pressures required is likely provides by turbulence – both viscous and electromagnetic as evidenced by independent simulations. We can also see that for ourselves in our images of molecular clouds.

Wolf Rayet Star – A Giant Star’s Transformation

Wolf Rayet Star – A Giant Star’s Transformation

The Crescent Nebula looks like supernova has gone off, creating the tendrilly patterns of material emitted or gathered up at the front of supersonic shock waves. The Crescent Nebula is not a supernova remnant, but contains a Wolf Rayet star at its heart.. However, unlike a massive star going supernova, only to leave a neutron or black hole behind, a giant Wolf Rayet star is left shining after the explosion(s). The star may even be following up with more either periodically or even continuously. In this short post, I merely speculate because I will have to learn more myself….

Collapse of a Molecular Cloud in 3 waves

Collapse of a Molecular Cloud in 3 waves

The standard textbooks indicate that the start or conception of a new star formation is the collapse of a molecular cloud.  But my background in thermodynamics, heat/mass transfer and fluid mechanics leaves this superficial explanation ungratifying (at least to me?).  This pervasive theory has already be debunked in my description of spiral galactic structure, but what should replace it?  What would cause a molecular cloud or part of one to “collapse”.  I have presented here, three variations of the same view of the Bernard 169 (the loopy one on the right), and Bernard 174 (shaped like a foot on the far left) – both molecular clouds in the process of “collapsing”, or as I would rather put it – condensing – towards star conception.  Both B169 and 174 are dark nebulae that emit no light of their own, but rather block light from the background and reflect any starlight from stars in their proximity.  There are indications, even in this dark nebula, of new star formation – can you spot them?

Circulation and Jewelry – The Galactic Spiral Structure (Part 5)

Circulation and Jewelry – The Galactic Spiral Structure (Part 5)

In the ultimate post of the series, we finally get to add some of the things that we image in galaxies – emissions, dust, and stars, to the stuff we can’t see – hydrogen and black holes. The stuff we can see brings life to the galaxy and are indeed necessarily for its longevity and new star production.
Gravity is shown to be periodic both in radial and angular directions, just like the spiral, but the various forces at play effect the galactic jewelry in different ways to give us regions of emissions, dust lanes, and star orbits. Explanations are provides as to why the arms can extend for radii way beyond what we do see, why dark matter is unnecessary (just a hydrogen accounting error). The spiral structure even explains why velocity vs radius plots look periodic when even dark matter doesn’t explain it.