In perusing the recent articles in the ApJ, one of the ones that caught my eye this week was one entitled, “26Al and the Formation of the Solar System from a Molecular Cloud Contaminated by Wolf Rayet Winds”. Quite the mouthful to be sure, but it's an interesting paper.The idea is that a number of unstable elements (specifically 26Al) are present in the oldest of meteoritic materials in higher concentrations than would be expected if our solar system had simply formed from the gravitational collapse of the local interstellar cloud. Their presence indicates that some sort of event happened near our solar system which injected these elements as the cloud underwent its collapse.
In general, heavy elements like aluminum are cooked up in stars. In fact, the ratios of elements observed in these remnants suggest it wasn't just any star, but a massive star. But once those elements are cooked up, the next trick is transporting them to our fledgling solar system. But how?
One obvious answer is to blow up the star that's making the elements in a supernova and spread them all over the place. Another possibility was that the elements were blown here in a gentler manner from a type of star known as a Wolf Rayet star. These stars are massive stars that are so hot, they blow off their outer layers.
The trick is to determine which of these possibilities was the real deal. Again, the ratios tend to rule out supernovae as a possibility due to the fact that such an occurrence “invariably over-predict the abundance of 53Mn”. To get the right abundances, the scenario that fit was that a nearby cluster of stars released the necessary elements as our solar system was forming, but while it was still dispersed enough to be vapor.
This paper really highlights one of the things I really love about astronomy and science in general; Small details, like the overabundances of rare materials in this case, can give hints at very grand questions, like where we came from. I find it amazing that we are capable of determining what our fore bearers must have been like even though they are no longer around just by looking at that which we carry inside our own solar systems and bodies.
Gaidos, E., Krot, A., Williams, J., & Raymond, S. (2009).
Al AND THE FORMATION OF THE SOLAR SYSTEM FROM A MOLECULAR CLOUD CONTAMINATED BY WOLF-RAYET WINDS
The Astrophysical Journal, 696 (2), 1854-1863 DOI: 10.1088/0004-637X/696/2/1854
7 comments:
Interesting!!
John, no offense, but you need to get back to writing more about astronomy (and even science in general). Your writing on the subject is what attracted me to your blog and I kept my subscription in your absence hoping that you would continue to write more about it soon.
Astronomy is an amazing subject and I would love to learn more about it (especially since I'm considering going into it as a career!!). So get writing damnit!!! :p
You'll be happy to know that the focus of my blog is likely going to start drifting back more towards science and science education. In the past, it's largely been concentrated on anti-science and atheism due to the fact that there was a very large anti-science movement at the time (with the Difficult Dialogue series here at KU, the Kitzmiller v. Dover case, Mirecki's case, etc.....) and I was heavily involved with SOMA.
Now that that's largely a thing of the past and I'm starting to work towards teaching, naturally my focus will be shifting to what I spend more of my time thinking about.
Jon, I loved it! I'm just a member of the general public, but for me it was like hearing the perspective of a single gene in fallopian tube cell peering into void and glimpsing the moment an egg and sperm unite. Wonderful!
I know that previously, those sorts of heavy elements were thought to have come from the supernova that may have triggered the original gravitational collapse of our system. Does this work put into doubt the idea that the collapse was supernova initiated? (I know there are other ways to start a collapse, just not as flashy.)
I'm not really sure what this would do to that theory. I haven't really read too much up on it. But if their presence was the main piece of evidence for the formation of our solar system, then I'd say this would definitely throw that into question.
However, it's probably not such a cut and dry case. It's almost certain that it wasn't just a Wolf Rayet star that made up our elemental distribution. If there was a cluster nearby enough to form WR stars, then there was probably also some supernovae there as well, but they may just have gone off at the wrong time to effectively seed our solar system (such as after collapse already began and the proto-disk was no longer gaseous).
You'll be happy to know that the focus of my blog is likely going to start drifting back more towards science and science education. In the past, it's largely been concentrated on anti-science and atheism due to the fact that there was a very large anti-science movement at the time (with the Difficult Dialogue series here at KU, the Kitzmiller v. Dover case, Mirecki's case, etc.....) and I was heavily involved with SOMA.
Now that that's largely a thing of the past and I'm starting to work towards teaching, naturally my focus will be shifting to what I spend more of my time thinking about.
Interesting!!
John, no offense, but you need to get back to writing more about astronomy (and even science in general). Your writing on the subject is what attracted me to your blog and I kept my subscription in your absence hoping that you would continue to write more about it soon.
Astronomy is an amazing subject and I would love to learn more about it (especially since I'm considering going into it as a career!!). So get writing damnit!!! :p
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