A Star forming question

[drbuck917]

For Professional Astronomer if possib
Re: Star forming regions

What, if known, causes these star forming regions? What causes the "star stuff" to collect in an area and for the material to start pulling together to form stars? Is it simply all gravity? Do these areas come and go? If so, I am sure it is over millions or more years so I can understand the answers to these questions may only be theory.
Thanks,
M. David Morales, M. D.
PS thanks for your website. Best on the web, in my opinion!!

[Chris Peterson]

Re: Star forming regions

What, if known, causes these star forming regions? What causes the "star stuff" to collect in an area and for the material to start pulling together to form stars? Is it simply all gravity? Do these areas come and go? If so, I am sure it is over millions or more years so I can understand the answers to these questions may only be theory.

Gravity is the only attractive force involved. It is operating in opposition to forces that tend to disperse clouds of gas and dust: stellar winds and simple kinetic dispersion. Under conditions where gravity dominates, material condenses. Gravity alone, however, doesn't seem to provide the necessary material density to create stars. We typically see star forming regions where shockwaves from exploding or very active stars create localized regions of very high density, at which point gravity again becomes dominant and stars are able to form.

Please be cautious using expressions suggesting something is only a theory. They are typically used by science deniers, pseudoscientists, and others you probably don't want to be associated with! In science, everything is described by theory. In the case of stellar formation, theory is far from complete, but in its broadest form (as outlined above), it is well supported by a wide range of observational and experimental evidence, and is therefore widely accepted and likely to describe how nature is actually operating.

[therodly1]

I have no idea if drbuck917 is still interested in star formation 3 months later but in case that person is, I thought I'd post.

I too found myself wondering about how a star forms, and where its planets and the rest of the family all come from.
Chris Peterson is right about theories. All sorts of people use them, and I tried, after reading as much as I could from a lot of different sources, not because I wanted to write a theory, but because I wanted a picture in my own head. But I also wanted it to conform to known science.

One of the biggest difficulties in creating a star formation theory is that you can't really test your hypothesis, you pretty much have to take your hypothesis and search the skies for evidence that may support it. And when what you are looking for is buried in a molecular cloud it becomes almost, if not absolutely, impossible.

What I am explaining to you will put me in the class of a pseudoscientist, which is alright(they have more fun).

Long story short, I progressed by reasoning out a process that might form stars, complete with attendant planets. In the process, if I encountered an issue that required an element of chance or a new kind of force, I restarted my theory. Very early on I became aware that I didn't have exacting enough knowledge in all the fields of science to fully develop my theory. There are just too many fields involved, and any star formation theory will be a result of many people's work, people that are no longer with us included.

So I wrote a slightly tongue-in-cheek essay on how to build your own star system. You, and others, may find it entertaining and it's available at:http://rlhicks.shawwebspace.ca/pages/vi ... tar_syste/

Added:
I did take this to the point where I reasoned out a scenario for providing angular momentum for the planets, which is a major stumbling block for star system formation.