The Stars of Tomorrow

June 8, 2007 — Leave a comment

What follows is my submitted entry for the Wellcome Trust’s New Scientist Essay Competition 2007. There are prizes involved and the top one is publication of the essay in New Scientist. I am very inexperienced with such things, but thought I’d enter anyway, so just in case I don’t win, I’ll publish this myself on the lowly but kindly Orbiting Frog. The images has been added for the blog entry only.

There is something special about the Sun. At least that’s how we all think here on Earth. Truthfully though, the Sun represents just one type of star – a common one in fact – in a catalogue of stars that is seen to be fairly consistent all over the universe. Understanding where that consistency comes from, and where the trillions of stars and their planets come from, are two of the goals of an area of astrophysics called star formation.

How the Sun came to be in this neck of the galactic woods with its family of planets, dwarf-planets and other miscellany – including us – is certainly worth knowing. It is fortunate then that star formation is about to boom.

ESA’s Herschel space observatory (launching 2008) and the upcoming SCUBA-2 camera (that will be fitted to the James Clerk Maxwell Telescope in Hawaii, in 2008) are two examples of a handful of eagerly anticipated instruments set to produce more data than star-formation researchers have ever had. They will enable astronomers to see deeper than ever before into the murky depths of the dustiest regions of the galaxy, where stars are born. Many of these sites are the beautiful nebulae now so familiar thanks to images like those from Hubble. Others are huge, dark clouds that are too cold and dense to see, but give away their location by obscuring background light.

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It is hoped that these new facilities with help answer several of the big questions facing astronomy. For example, why do stars form in clusters of hundreds or thousands? Why do they have the same catalogue of masses that is seen everywhere we look? What are the initial conditions of planet formation?

The physics involved crosses huge orders of scale. A good demonstration is this: imagine the Sun were a metre across. At this scale the nebula from which it formed would be the size of France! Incidentally that makes the Earth a mere pea. To compress all that material down by a factor of a million in size involves complex physics. In order to understand where we came from, you need to understand that physics.

As a discipline, star formation slots into almost all areas of astrophysics. For instance, in order to study galaxies you need to know what they’re made of. Even cosmology, often seen by its champions as being less ‘astro’ and more ‘physics’ has recently encountered a star-formation problem. In order to account for observations of stars that appear to be as old the universe itself, they need to explain how a population of stars could have formed so rapidly and so soon after the Big Bang. Whichever angle you look at it from, star formation is vital to modern astronomy.

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Star formation is also important to you, personally. This isn’t just because the various stages of stars give you pretty objects like the Orion Nebula and the Pleiades (above) to look at with your telescope. Star formation tells us something very fundamental: we are all made of stardust. The Sun, planets and everything else around us were formed from the same giant cloud of material – most likely a cloud left over from an even older star when it died. Yet that same process creates a whole array of stellar classes and different planetary characteristics. Only star formation can tell us how all of this works.

NASA’s planned Darwin mission and ESA’s Terrestrial Planet Finder will both be able to resolve Earth-like planets around other stars. These, along with Herschel and SCUBA-2 will enable us to look at whole stellar systems from the outside, a perspective we have never had before. Observers will look at systems like our own at various stages of existence, from barely formed blobs about to start collapsing under gravity through to ancient star systems; we will even see planets in formation.

As a subject, star formation is set to explode. It will allow us to see ourselves better than ever before and to understand the origins of our existence. This is inspirational science, and definitely worth keeping an eye out for in the years to come.

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