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Hi, I'm Stuart Gary, I'm a journalist and broadcaster with the Australian Broadcasting Corporation. I love science, especially the majesty and wonder of space, so I put together a weekly astronomy show for the ABC called StarStuff.
In my spare time I like to fly planes, practice karate and pistol target shooting and play around with my cars, a twin Turbocharged Falcon GT Interceptor and a DeTomaso Pantera GTS.
I’m vegan, a life member of the RSPCA and a supporter of several animal welfare organisations.
My other great passion is music which is understandable when you realise that I was a radio music jock long before I became a journalist. My record library contains tens of thousands of singles, albums, videos, CD’s and DVDs. These days that’s all stored in an 8 terabyte raid enclosure linked to a desk top PC at home. My tastes range from rock and grunge through to trance and new romantics. At the moment I’m listening to heaps of MGMT, William Control, Hawthorne Heights and Short Shack, but I have lots of time for the classics like Placebo and the early stuff from Silverchair, In fact Neon Ballroom is still my favourite album, and Emotion Sickness is still one of my two favourite songs (the other being William Control’s Death Club).
StarStuff is a great name for the show, but it works on more levels than just astronomy, it’s really cool for any science program because everything in the universe after the quark gluon plasma of the big bang is star stuff even the iron which makes your blood red was manufactured in the supernova explosions of stars. Carl Sagan said it best, we are all star stuff.
This blog is designed to allow me to publish all the things which can’t fit into StarStuff. There’s heaps of really interesting stuff out there and only a half hour window for the show, so each week becomes a battle to try and squeeze it all in. This blog lets me do that.
You can check out the show at the offical ABC StarStuff website:
http://www.abc.net.au/science/starstuff/
There's also an official ABC StarStuff Twitter feed: @abcstarstuff
And an official ABC Science website: http://www.abc.net.au/science/
The legal stuff: This is my personal blog. The views expressed in this blog are those of me only and not the Australian Broadcasting Corporation or its management. I do not claim ownership of any of the media in this blog. where possible credit and or source will always be given. If one of your photos or other media is submitted in this blog and you would like it removed please let me know.
Old Star, New Trick
The Big Bang produced lots of hydrogen and helium and a smidgen of lithium. All heavier elements found on the periodic table have been produced by stars over the last 13.7 billion years. Astronomers analyze starlight to determine the chemical makeup of stars, the origin of the elements, the ages of stars, and the evolution of galaxies and the universe. Now for the first time, astronomers have detected the presence of arsenic and selenium, neighboring elements near the middle of the periodic table, in an ancient star in the faint stellar halo that surrounds the Milky Way. Arsenic and selenium are elements at the transition from light to heavy element production, and have not been found in old stars until now.
Lead author of the Astrophysical Journal paper, Fellow Ian Roederer of the Carnegie Observatories explained: “Stars like our Sun can make elements up to oxygen on the periodic table. Other more massive stars can synthesize heavier elements, those with more protons in their nuclei, up to iron by nuclear fusion—the process in which atomic nuclei fuse and release lots of energy. Most of the elements heavier than iron are made by a process called neutron-capture nucleosynthesis.
“Although neutrons have no charge, they can decay into protons after they’re in the nucleus, producing elements with larger atomic numbers. One of the ways that this method can work is by exposure to a burst of neutrons during the violent supernova death of a star. We call this process the rapid process (r-process). It can produce elements at the middle and bottom of the periodic table—from zinc to uranium—in the blink of an eye.”
Roederer, with co-author James Lawler, looked at an ultraviolet spectrum from the Hubble Space Telescope public archives to find arsenic and selenium in a 12 billion year-old halo star dubbed HD 160617. These elements were forged in an even older star, which has long since disappeared, and then—like genes passed on from parent to infant—they were born into the star we see today, HD 160617.”
The team also examined data for this star from the public archives of several ground-based telescopes and were able to detect 45 elements. In addition to arsenic and selenium, they found rarely seen cadmium, tellurium, and platinum, all of which were produced by the r-process. This is the first time these elements have been detected together outside the Solar System. Astronomers cannot replicate the r-process in any laboratory since the conditions are so extreme. The key to modeling the r-process relies on astronomical observations.
“What I find exciting is that arsenic and selenium can be found in other stars, even ones like HD 160617 that we’ve been studying for decades,” remarked Roederer. “Now that we know where to look, we can go back and study these elements in other stars. Understanding the r-process helps us know why we find certain elements like barium on Earth, or understand why uranium is so rare.”