Star formation is a complex business. To make a baby star, you need to start with a large, amorphous bubble-like cloud of gas and dust and compress it to the densities needed to trigger nuclear fusion. For this process to work you also need to remove a lot of heat. This is because as the gas cloud is compressed it heats up and a hot gas cloud can just sit there in equilibrium forever. So, as the gas cloud is compressed, you must also remove heat from the system so that it can be compressed even more. Modern gas clouds do this by emitting radiation as they compress, and elements heavier than the sun (in the world of astronomy these are usually called metals) do a fantastic job of removing heat from the collapsing gas clouds. But in the early universe these gas clouds were much more primordial, having little or no metals in them. Remove all ads on Universe Today Join our Patreon for just $3! Get the ad-free experience of a lifetime Astronomers still do not understand how stars grew in such a metal-poor environment. One way to deal with this problem is to use massive observatories like the James Webb Space Telescope. Another way, led by Professor Toshikazu Onishi of Osaka Metropolitan University and Assistant Professor Kazuki Tokuda of Kyushu University, is to look closer. Like the Small Magellanic Cloud. (Left): Wide-field far-infrared image of the Small Magellanic Cloud taken with the Herschel Space Observatory. (Right): An image of the molecular outflow from the baby star Y246. The cyan and red colors show the red-shifted gas seen in the carbon monoxide emission. The cross indicates the position of the star. Image credit: ALMA (ESO/NAOJ/NRAO), Tokuda et al. ESA/Herschel The Small Magellanic Cloud is not as pristine as the early universe, but it has far fewer metals than the average in the Milky Way galaxy. And as an added bonus, it is much more accessible to us than the early universe. The international team of astronomers recently used ALMA, the Atacama Large Millimeter/submillimeter Array, and caught a baby star in the process of formation. They observed extremely fast outflows from the newborn star. These outflows are driven by incredibly strong electric and magnetic fields in the gas cloud as it compresses. Astronomers believe that these kinds of outflows suppress the rotational motion of the gas around the newly formed star. This slowing increases the growth rate, potentially leading to larger stars. Further research will reveal whether this is a common method of star formation in the early universe, potentially leading to stars much larger than today’s average.
Like this:
Like Loading…
