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About Me

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.

Blogs I follow:

Theme by: Miguel
  1. MILKY WAY’S BLACK HOLE GETTING READY FOR SNACK Get ready for a fascinating eating experience in the center of our galaxy. The event involves a black hole that may devour much of an approaching cloud of dust and gas known as G2. A supercomputer simulation prepared by two Lab physicists and a former postdoc suggests that some of G2 will survive, although its surviving mass will be torn apart, leaving it with a different shape and questionable fate. The findings are the work of computational physicist Peter Anninos and astrophysicist Stephen Murray, both of AX division within the Weapons and Complex Integration Directorate (WCI), along with their former postdoc Chris Fragile, now an associate professor at the College of Charleston in South Carolina, and his student, Julia Wilson. They came up with six simulations, using the Cosmos++ computer code developed by Anninos and Fragile, which required more than 50,000 computing hours on 3,000 processors on the Palmetto supercomputer at Clemson University in Columbia, South Carolina. Previous simulations of the upcoming event had been done in two-dimensions, but the Cosmos++ code includes 3D capability, as well as a unique “moving mesh” enhancement, allowing the simulation to more-efficiently follow the cloud’s progression toward the black hole. The black hole is known as Sgr A*. “Sgr” is the abbreviation for Sagittarius, the constellation near the center of the Milky Way. Most galaxies have a black hole at their center, some thousands of times bigger than this one. “While this one is 3-to-4 million times as big as our Sun, it has been relatively quiet,” according to Murray. “It’s not getting fed very much.” Contrary to their name, black holes can appear very bright. That’s because gas orbiting them loses energy via friction, getting hotter and brighter as it spirals inward before falling into the black hole. The composition of the G2 cloud is still a mystery. Astronomers originally noticed something in the region in 2002, but the first detailed determinations of its size and orbit came only this year. The dust in the cloud has been measured at about 550 degrees Kelvin, approximately twice as hot as the surface temperature on Earth. The gas, mostly hydrogen, is about 10,000 degrees Kelvin, or almost twice as hot as the surface of the Sun. Its origin is still unknown. Murray says: “The speculation ranges from it having been an old star that had kind of a burp and lost some of its outer atmosphere, to something that was trying to be a planet and couldn’t quite manage it because the environment was too hot.” As the cloud approaches the black hole and begins to fall in to what Murray describes as “a gravity well” beginning next September, it will begin to shed energy, causing it to heat to incredibly high temperatures, visible to radio and X-ray telescopes on Earth as well as orbiting satellites such as NASA’s Chandra X-ray Observatory. But it won’t be a collision course. The point at which a stellar object can no longer escape being swallowed by a black hole is known as the Schwarzschild radius, a quantity whose value depends on the black hole’s mass, the speed of light and the gravitational constant. The cloud will actually pass far enough away that it will escape the point of no return by approximately 2,200 Schwarzschild radii, which in this case is about 200 times as far as Earth is from the Sun. But the supercomputer simulations show that the cloud will not survive the encounter. According to Anninos: “There’s too much dynamical friction that it experiences through hydrodynamic instabilities and tidal stretching from the black hole. So a lot of its kinetic energy and angular momentum will be dissipated away and it will just sort of break up into some sort of incoherent structure. Much of it will join the rest of the hot accretion disk around the black hole, or just fall and get captured by the black hole. It will lose a lot of its energy but not all of it. It will become so diffuse that it’s unlikely that any remnant of the gas will continue on its orbital track.” The close encounter will take several months. The entire event is predicted to last less than a decade. The simulation is posted on the Web at http://fragilep.people.cofc.edu/research/cloud.html It shows the cloud modeled as a simple gas sphere, near the point in its orbit where it was first discovered. As it approaches Sgr A*, a process known as tidal stretching increasingly distorts the cloud. By the end of 2012, the cloud will be nearly five times longer than it is wide. Along with tidal stretching, the cloud also experiences resistance in the form of ram pressure as it tries to plow through the hot interstellar gas that already fills the space around Sgr A*. The interactions of G2 with this background gas cause further disruptions to the cloud from Rayleigh-Taylor and Kelvin-Helmholtz instabilities. Collectively, these effects act to strip some material from the cloud and feed it into Sgr A*. IMAGE….Simulations of the dust and gas cloud G2 on its orbit around the Milky Way central black hole SgrA*. Photo courtesy of M. Schartmann and L. Calcada/ European Southern Observatory and Max-Planck-Institut fur Extraterrestrische Physik.

    MILKY WAY’S BLACK HOLE GETTING READY FOR SNACK

    Get ready for a fascinating eating experience in the center of our galaxy.

    The event involves a black hole that may devour much of an approaching cloud of dust and gas known as G2.

    A supercomputer simulation prepared by two Lab physicists and a former postdoc suggests that some of G2 will survive, although its surviving mass will be torn apart, leaving it with a different shape and questionable fate.

    The findings are the work of computational physicist Peter Anninos and astrophysicist Stephen Murray, both of AX division within the Weapons and Complex Integration Directorate (WCI), along with their former postdoc Chris Fragile, now an associate professor at the College of Charleston in South Carolina, and his student, Julia Wilson.

    They came up with six simulations, using the Cosmos++ computer code developed by Anninos and Fragile, which required more than 50,000 computing hours on 3,000 processors on the Palmetto supercomputer at Clemson University in Columbia, South Carolina.

    Previous simulations of the upcoming event had been done in two-dimensions, but the Cosmos++ code includes 3D capability, as well as a unique “moving mesh” enhancement, allowing the simulation to more-efficiently follow the cloud’s progression toward the black hole.

    The black hole is known as Sgr A*. “Sgr” is the abbreviation for Sagittarius, the constellation near the center of the Milky Way. Most galaxies have a black hole at their center, some thousands of times bigger than this one.

    “While this one is 3-to-4 million times as big as our Sun, it has been relatively quiet,” according to Murray. “It’s not getting fed very much.”

    Contrary to their name, black holes can appear very bright. That’s because gas orbiting them loses energy via friction, getting hotter and brighter as it spirals inward before falling into the black hole.

    The composition of the G2 cloud is still a mystery.

    Astronomers originally noticed something in the region in 2002, but the first detailed determinations of its size and orbit came only this year. The dust in the cloud has been measured at about 550 degrees Kelvin, approximately twice as hot as the surface temperature on Earth. The gas, mostly hydrogen, is about 10,000 degrees Kelvin, or almost twice as hot as the surface of the Sun.

    Its origin is still unknown.

    Murray says: “The speculation ranges from it having been an old star that had kind of a burp and lost some of its outer atmosphere, to something that was trying to be a planet and couldn’t quite manage it because the environment was too hot.”

    As the cloud approaches the black hole and begins to fall in to what Murray describes as “a gravity well” beginning next September, it will begin to shed energy, causing it to heat to incredibly high temperatures, visible to radio and X-ray telescopes on Earth as well as orbiting satellites such as NASA’s Chandra X-ray Observatory.

    But it won’t be a collision course.

    The point at which a stellar object can no longer escape being swallowed by a black hole is known as the Schwarzschild radius, a quantity whose value depends on the black hole’s mass, the speed of light and the gravitational constant.

    The cloud will actually pass far enough away that it will escape the point of no return by approximately 2,200 Schwarzschild radii, which in this case is about 200 times as far as Earth is from the Sun.

    But the supercomputer simulations show that the cloud will not survive the encounter.

    According to Anninos: “There’s too much dynamical friction that it experiences through hydrodynamic instabilities and tidal stretching from the black hole. So a lot of its kinetic energy and angular momentum will be dissipated away and it will just sort of break up into some sort of incoherent structure. Much of it will join the rest of the hot accretion disk around the black hole, or just fall and get captured by the black hole. It will lose a lot of its energy but not all of it. It will become so diffuse that it’s unlikely that any remnant of the gas will continue on its orbital track.”

    The close encounter will take several months. The entire event is predicted to last less than a decade.

    The simulation is posted on the Web at http://fragilep.people.cofc.edu/research/cloud.html

    It shows the cloud modeled as a simple gas sphere, near the point in its orbit where it was first discovered. As it approaches Sgr A*, a process known as tidal stretching increasingly distorts the cloud. By the end of 2012, the cloud will be nearly five times longer than it is wide.

    Along with tidal stretching, the cloud also experiences resistance in the form of ram pressure as it tries to plow through the hot interstellar gas that already fills the space around Sgr A*. The interactions of G2 with this background gas cause further disruptions to the cloud from Rayleigh-Taylor and Kelvin-Helmholtz instabilities. Collectively, these effects act to strip some material from the cloud and feed it into Sgr A*.

    IMAGE….Simulations of the dust and gas cloud G2 on its orbit around the Milky Way central black hole SgrA*.
    Photo courtesy of M. Schartmann and L. Calcada/ European Southern Observatory and Max-Planck-Institut fur Extraterrestrische Physik.

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