On March 10 a team of Canadian and American astronomers released the results of a study done using the Atacama Large Millimeter/submillimeter array (ALMA), combined with former observations by both the Submillimeter Array (SMA) in Hawaii, and the Hubble Space Telescope. What researchers found is that even more than the weapon in George Lucas’s Star Wars films, real-life death stars not only obliterate anything too near them, but even prevent creation.
A nebula is an interstellar formation of dust and gases. Stars and even planets are created over time from the materials within a nebula. Gases and dust within the formation attract other matter, until what began as a clump is a star. Proplyds are protostars, or stars that are so young as to not quite have star classification. Astronomers have been studying these protostars along with their larger counterparts, and have been most recently tracking their creation within the Orion Nebula. The focus of the study has been on the deadly relationship between massive, O-type stars (described as monsters when compared with our significantly smaller Sun) and newly forming protostars, or proplyds.
Researchers found that within 600 billion miles or 0.1 light years, matter within a protostar is stripped away faster than a planet can form, and the proplyd is obliterated, resulting in the death of the young star. Anything outside this radius is safe. O-type stars come with an amount of ultraviolet radiation that is so destructive to anything within its path, researchers say surrounding areas are not just inhospitable as formerly thought, but are downright deadly.
Ironically, it is the supernova stage of an O-type star that is necessary for the creation of new stars and planets, with the after-effects of its self-destruction creating an effect known as seeding, where bits of dust and matter are peppered around a vast region created by the blast. Researchers have also found that O-type stars are not created in isolation, as previous theories posited. Rather, nebulae are virtual stellar nurseries where families or groups of stars are formed together over time. When a nebula is left to its own devices, i.e. it does not stray within the danger zone of a death star, it can become more than a nebula: it can become the creation of a whole new star system, something not even George Lucas could have envisioned. It eventually floats away with all its new stars and planets, and becomes a new creation within the galaxy. But if an embryonic star system gets too close to a death star it cannot survive the blast of ultraviolet radiation, as a protoplanetary disk’s gases are heated up until the disk is broken apart and more, swept away.
The new technology of ALMA, besides learning how a death star brings destruction to nearby stellar systems, has shown more than this: there are a much greater number of proplyds and protoplanetary disks in Orion than previously known. ALMA can also see beyond a disk’s surface area right into its interior to measure a proplyd’s mass. Astronomers have discovered that when outside the deadly radius of an O-type star, proplyds have a mass of anywhere from one to 80 times what is needed to create a planet the size of Jupiter, whereas within the danger-zone this is reduced to just a fraction of the mass necessary to create one such planet. A death star creates as it destroys, but while burning wreaks more havoc than the weapon conceived by George Lucas for the Star Wars movies. Researchers have learned enough through ALMA to make them think one day we may be able to discover more solar systems similar to ours, including how common they are. Then, fans of George Lucas will have the best creation: more space to explore than ever before.
By Julie Mahfood
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