So, three times as many stars as previously thought. What does this mean for:
Various theories about the universe in terms of the big bang, string theory, etc.
Does it do anything for certain ideas about the “missing mass” problem and attempts to address it like dark matter?
Does this have any implications at the quantum level?
And any other science implications I might have not called out.
I’m gonna say “No” to all questions.
Sorry, Philster, but you got #1 wrong.
Come on guys, just “No” or “Yes” isn’t an adequate answer to these questions. At least give some explanation.
You can read the actual paper here. I hate to break it to you, but this paper isn’t really hugely earth-shattering. For one thing, it never says that there should be three times as many stars. That seems to just come out of nowhere. For what it does say, let me start from the beginning.
Astronomers use this thing called the “initial mass function” or IMF which describes how common stars are of different masses. Higher mass stars are rarer for many reasons, but the primary one is that the larger the star, the faster it burns through its fuel using fusion, and so very massive stars have much shorter lifetimes. For the very largest stars, we are talking lifetimes as short as a few million years. For the very smallest, which burn through their fuel with fusion the slowest, the lifetimes can be trilions of years. As a result, pretty much every small star ever formed still exists, while big ones are just flashes in the pan and there aren’t too many at any given time.
There are lots of other factors involved, of course, that affect the IMF, things like how the huge gas clouds that form stars behave (particularly right before ignition) and so on.
This brings us to the paper discussed in that news article. That paper says this:
There are many more small stars found in small elliptical galaxies very far away than the current standard IMF predicts.
What does this mean? Well, the authors say there are a few conclusions we should draw:
-Early galaxies seem to have more dwarfs. This means that our theories of the early universe require a very minor correction (honestly, this is going to be an unnoticeably small difference to most of the world - it will end up being something like “There was 22% helium right after the big bang, not 25% helium,” which maybe ought to give you a sense of how damn hard it is to be a cosmologist).
-The IMF is probably broken. The current assumption is that we can almost entirely look at the rate-of-burning to determine the IMF, but in reality, it seems that we will need to also take into account the type of galaxy the star is in. This mostly means lots of headaches for everyone since it will just make things much more complicated.
-Finally, they cite this paper to say that their results may mean that we require less dark matter to account for the centers of nearby massive galaxies - they don’t speculate at all on the dark matter “halos” which are really much more important, though.
So there you go! It’s not as mindblowing as you may hear in the news, but its still pretty interesting and important. This is science in action, always fun to see.
Show your work.
None of this is going to topple any theories.
It means that even if red dwarf systems need very special circumstances to have habitable planets, the sheer number of them would mean that habitable planets are more common throughout the universe than previously thought.
Not necessarily. More dwarfs could mean that the metallicity of the universe is lower, since there could be fewer large stars to produce supernovae which generate the metals. By almost all models, low metallicity will decrease the rate of planet formation.
Probably a stupid question but how would the type of galaxy affect a star’s burn rate. Sorry if I completely missed the point.
It wouldn’t. Most likely it means that red dwarfs form at higher rates relative to other types in elipticals.
Now as I understand it, elipticals have a very low rate of star formation. Such galaxies are formed by the collision of two galaxies. During the collision, there’s a big orgy of star formation, as the gas and dust clouds of the two galaxies collide and thus collapse into stars. This uses up most of the free gas and dust, so few further stars form in that type of galaxy.
Based on this, my guess is that this mode of star formation (collision of gas clouds from two different galaxies) results in far more red dwarfs forming than the more sedate mode that occurs in ordinary galaxies. However, I am not an astronomer, so I could be way off base.
In a way, this is the point. Since there is no plausible way that the type of galaxy affects a star’s burn rate, this research conclusively shows that there must be another, independent factor that determines the IMF - specifically, galaxy type. The burn rate explanation of the IMF is pretty good, but it apparently doesn’t cover everything.
Not too far off base, but a few small errors here and there.
The usual story goes that ellipticals are really old, and date back to the first generation of post-big-bang galaxy formation. They were originally supposed to be relatively small, but have undergone mergers, as you say, possibly many of them, to give them the sort of oblong elliptical shape.
This would indeed create an orgy of star formation, but most likely only at the outer edges of the galaxy. The core should remain pretty much the same - this is theory not backed up by observation, although the latest generation of telescopes might be able to do it with a heavy dose of adaptive optics. But the point is that this study found evidence for even more dwarfs at the cores of elliptical galaxies, not just the edges.
So the main question is what we got wrong about the formation of the original elliptical cores, not so much what we got wrong about collisions, although that is an interesting avenue and one well worth exploring in more detail.