Is the sun an only child? or (very very) extended family?
The answer tells us more than just how awkward a holiday family reunion is (if you think your reunion is bad, how bad is your reunion with thousands of sibling rivals)? Please try to imagine). After all, the story of the origin of the Sun is ultimately our own. Although our understanding of how stars form has advanced by leaps and bounds, ironically, some pretty fundamental questions still remain about our nearest and dearest stars. Whether the sun was born alone or with a huge passage of other stars, and so on.
Even though the Sun is so close that we can almost touch it, the biggest problem with discovering its origin story is that it’s old. , is quite middle-aged and has wandered far from his ancestral home. An unnamed, now-defunct stellar nursery of gas that long ago dispersed or merged into stars.
We can’t find the nursery school. But we can still learn about itPerhaps surprisingly, there is some evidence in the form of meteorites, some of which still hold clues about the surrounding gestational environment at the time of the birth of the solar system. Isotopes of elements have told us where meteorites formed in the presolar nebula. Also, variations between meteorites can be used to help determine the state of the nebula long before the planet emerges.
With data from meteorites at hand and using state-of-the-art computer simulations, an international team of astronomers has recently published their results to investigate the potential birthplace of the Sun. Monthly Notices of the Royal Astronomical SocietyUsing clever reasoning, their research suggests that the Sun not only had many siblings, but was born in a fairly metropolitan neighborhood.
A star is born in a cosmic cloud called a nebula, and its interior collapses into a central mountain-like point that becomes a nascent star. Nebulae come in all shapes and sizes, from tiny dark spheres to giant molecular clouds. How stars form in a given nebula is more a story of nature than of nurture.
For example, the nearby nebula Barnard 68 is a dark mass of cold gas and dust, small particles of silicate (rock matter) and complex carbon molecules resembling soot, relatively close in space, with only a few hundred Only light years away. This is my favorite object he is one. An eerie, pitch-black ghostly mass that completely blocks out all light from the stars behind it, like an opaque hole in the sky.
Only 0.5 light-years (about 3 trillion miles) across, there is hardly enough material to make a single star slightly more massive than the Sun. It is likely in the middle of that process now and could transform into a star in just 200,000 years.
On the other side of the scale is the Orion B molecular cloud complex. It is a truly gigantic site of active star formation, over 1,000 light-years distant and hundreds of light-years across. Robust enough to create at least 100,000 stars, a staggering number like the Sun. The iconic Orion Nebula, visible to the naked eye and home to hundreds of star births, is just a small part of this massive stellar factory.
Massive clouds like this are relatively rare, but they produce stars on an industrial scale. The small clouds are non-fertile, but scattered throughout the galaxy.The origin of the Sun cannot be determined just by looking at these numbers statistically. It could have come from either kind of stellar nursery.
However, the environments of these nebulae are very different, affecting the stars they create. A massive star found in a nebula has a big impact on a pregnant sibling. They are capable of blowing a violent wind of subatomic particles. It is similar to the solar wind, but rises with a force far greater than 11 degrees. These winds can sprinkle the forming star with heavy elements such as aluminum and magnesium. Then, when it explodes as a supernova, different mixtures of these elements, such as iron and cobalt, are flung very far.
However, massive stars are rare. Perhaps 1 in 100 stars are big enough to hold this kind of wobble, and small nebulae simply can’t make them. So, in principle, if you look at the chemical composition of the early solar system, you can tell what kind of nursery the Sun was born in.
This was the focus of the newly published study. The astronomer focused on his two elements in particular, aluminum-26 and iron-60. Aluminum-26 is made inside massive stars and blown away by the wind, while Iron-60 is forged in the thermonuclear hell of exploding stars. Both elements are radioactive and decay to magnesium and cobalt, so careful measurements of the abundance of these daughter elements in the early days of the solar system, i.e. in original samples from meteorites, will give us insight into the environment in which the sun formed. I can.
For their new analysis, an international team of scientists will use the physics of nebulae and star formation to create images ranging from nebulae containing very few stars (surrogates for small clouds) to thousands of giants. They simulated the birth of Sun-like stars in different environments. was compared with that measured at
Their results show that the early Sun was likely beaten down by powerful winds and supernova explosions when it formed in its natal disk. So the Sun Nursery resembled the Orion Complex more than the Bernard 68.
In other words, Sun was probably more like a downtown kid than a rural small-town star. After all, you can never go home again.
And what about the Sun’s brothers, the thousands of other stars in that vast family? Like the Sun, they once cuddled together like puppies, but perhaps long ago wandered on their own and now Orphaned and scattered across the galaxy. Still, astronomers search for ones with the same age and composition as the Sun so they can learn more about their parent stars.
The chances of a reunion are pretty low. If you want to see a family album, you have to assemble it yourself.
This is an opinion and analysis article and the views expressed by the author or authors are not necessarily Scientific American.
