Archive for the 'news' Category

HD 98800 – the polar circumbinary disk

As outlined in the paper and the press release (free PDF here), we have discovered that the HD 98800 quadruple star system hosts a disk that orbits at right angles to the binary it surrounds.

Here is Fig. 1 from the paper, which shows the setup. If the geometry of the disk around the inner binary doesn’t make sense, try taking a look at this simulation.

The HD 98800 system
The HD 98800 system

What does this show? The system has two binaries, A and B, which orbit each other at a distance of about the Pluto-Sun distance. Since both A and B are binaries, the individual stars are called Aa and Ab, and Ba and Bb. The “inner binary” BaBb is surrounded by a ring of gas and dust about the size of the Asteroid belt, this is shown in the right panel. All that is then orbiting the other binary, AaAb. The curious thing is that none of the orbital planes are aligned, and the BaBb plane is at right angles to the plane of the disk.

This system should prove very valuable to people that are interested in disk physics – here we can quantify the effects of the stars on the disk so compare the data with models. Of course, it’s possible that the disk is forming planets, and there is evidence that suggests this is underway, meaning that polar circumbinary planets may exist and be found in the future!

Discovery of the Fomalhaut C debris disc

This isn’t a photo for a change. It’s a graphic from a press release about my discovery of a debris disk around Fomalhaut C.

Artists illustration of Fomalhaut C, with Fomalhaut A in the background. Credit: Amanda Smith

Artist’s illustration of Fomalhaut C, with Fomalhaut A in the background. Credit: Amanda Smith

The story has travelled far, including (but not limited to) ABCastrobites, Centauri Dreams, CNES & CNRS (French), Discovery News, Natureslashdot & Universe Today.

Climate change opinion change?

There is a BBC article today, noting how a recent poll shows an increase in the number of people who don’t believe in climate change (what we used to call global warming). Apparently three months ago, 15% of people in the UK didn’t think climate change was taking place, now 25% think so. The conclusion is that recent events, a “series of high profile climate-related stories, some of which made grim reading for climate scientists and policymakers” has caused the change. However, 73% of folk aware of said news hadn’t let it change their minds, apparently “people tend to make judgements over time based on a whole range of different sources.”

So people can be swayed by news and change their minds on the existence or otherwise of global warming or otherwise in three months, yet at the same time get a feeling for what’s happening over longer timescales. Somewhat contradictory conclusions? Yet the results are obviously “very disturbing” and “action is urgently needed.” Action to educate that global warming is real that is.

Indeed, I agree more education would be great, and with that how about some education about critical thinking? While the surveyors note that it’s “very unusual indeed to see such a dramatic shift in opinion in such a short period,” they still take the results at face value, rather than wondering if perhaps the differences between the two surveys are an indication of their error due to some systematic effect. While there may have been some real change in the number of (landline owning) people (try running it monthly and looking at the scatter), I find this blind faith in the results being representative of the real world a bit hard to swallow.

Corruption Perception Index

New Zealand: Perceived as the worlds least corrupt country in 2009. Does this result mean we’re (NZers) simply the most gullible people? (It’s not clear whether the perceptions are of individuals of each country however)

Vicotria Bushfires

ABC has an amazing website dedicated to telling the entire story of the 2009 bushfires(0)

Bushfire light?

There’s been some crazy and beautiful light around Dunedin today, and probably over much of New Zealand. I bet it’s smoke from the fires in Australia: the result of the brutal summer they’re having.

Dunedin sunset

Dunedin sunset

Light air rises

Normally hot air rises, but light air does also, in the way that it escapes from the atmosphere more easily than things like nitrogen, oxygen, and carbon dioxide. If we’re not more careful to conserve helium when we get it out of the ground in the future, our kids might miss out on the fun it brings when the party’s over and it’s time to talk funny. As a side effect, science will also suffer(0)

Finding planets

CoRoT is discovering exo-planets at a rate only set by the available resources to follow up the detections


I commonly listen to Late Night Live on my way to and from school. It’s an Australian radio show hosted by Philip Adams, who interviews people from pretty much any field you can think of.

Today he was talking to Chalmers Johnson, who has written several books on how the USA has gotten itself into trouble of late. The latest is called “Nemesis,” which draws parallels between the current military overreach of the USA, and the collapse of the Roman empire. The interview was very interesting (get it here). Here’s a wee bit that Johnson said at one point during the interview:

The world balance of power did not change one iota from September 11 to September 12. If the terrorists were to actually have a major impact upon the USA, it would have to be because we bungled the reaction, which is precisely what we did do. We started to declare something totally unprecedented and not needed, a war on terrorism, a war on the techniques, not a good idea. We refused to even contemplate serious police methods. We could have retained the support of virtually all of the world, including most of the Arab middle east, had we devoted ourselves to running down Osama Bin Laden and his associates in caves in Afghanistan. We knew where they were since we’d helped them build them in the 1980’s in the war with the Soviet Union. Had we done it seriously, not done it just with airplanes, but put serious ground forces into Afghanistan, it probably could have been handled quickly and fairly easily and coolly. Instead, it was seen as an opportunity for the neo-conservatives in the USA to expand presidential powers, to move the center of gravity of the operation of our foreign policy from the Department of State to the Department of Defence. The two old bureaucratic warriors were very skilled, namely Cheney and Rumsfeld, more or less made fools out of two attractive but not apparently terribly bright figures in our government, Colin Powell and Condeleezza Rice, and they also exploited a neophyte president who didn’t really know what he was doing, and was in over his head.

Johnson was also on another podcast I listen to, Democracy Now, a while ago.

Fear not…

…for I am with thee (Isaiah 43:5, and other translations).

However, it looks like there’s still hope for the godless among us, thanks to some clever scientists who have found a “pathway for extinction of contextual fear” in (presumably godless) mice.

Being able to do the most fearful things, like asking a girl out for example, may be simpler in the future when the cure for fear comes out. If it comes as a tasty liquid medicine, and avoids side effects such as loss of the ability to operate heavy machinery, then it just might replace the current favourite for fearful situations. Only time will tell whether it’ll retail for $7.95 and be as good as a Long Trail Hefeweizen…

Flight of the Conchords in NY

NZ seems so much funnier when I’m not living there…

Flight of the Conchords has a show on HBO coming up, the trailer is very funny, as is the music video…

cn u pass nz exms?

I sometimes wonder about my kiwi education. I think I missed out by not doing history and geography, but it appears my ability to (mostly) spell words properly may become a real asset.

If kids have to resort to speaking ‘txt’ in exams then something is wrong. Why not have Vodafone and Telecom block text messages that aren’t written in full proper english? Since I’ve always made the effort to use real words that would be awesome…

Here’s a few articles: first one | the fallout

snowy super-Earth press release

The Harvard-Smithsonian Center for Astrophysics (CfA) have put out a press release relating to our recently accepted ‘super-Earth’ paper (astro-ph/0609140, ApJL). It’s also on Universe today which is very cool.

This blog has rewritten what happens and makes some good points about what a super-Earth really is, and about disk masses which do have a wide range. Our model uses a disk that is reasonably massive, for this and dynamical reasons we don’t expect planets much larger than ~5 Earth masses to form in this manner.

There are even a few sites I’ve never heard of that have the release: Spaceflight Now, and Space Daily.

It seems a tad unfortunate that today a light plane crashed into an apartment building in Manhattan. It’s probably best when press releases go out on ‘no news’ days… (because this is obviously front page news)

In case you’re wondering, below is an artists image of a super-Earth, an icy planet several times further away from a dim ‘red dwarf’ star than the Earth is from the Sun.

it really does look like this

cats on Mars?

I thought the Astronomy Picture of the Day today looked like the face of a cat when it turned up in my google desktop plugin.


Upon opening the real APOD page it turned out to be ‘the unusual stone mesas of the Cydonia region on Mars’.

Oh well

toys and election

well another exciting weekend has passed. i figure if i keep trying to put in entries documenting what i did each week i’ll be able to look back and convince myself i haven’t wasted my life.

i finally bought an ipod, and can now back up my computer without having to exclude the pictures and other stuff. maybe it’ll excite me into riding my bike more too.

on saturday we watched the nz election on tv. the most exciting parts were when nobody won (just like in germany), peter dunne opened his victory speech by complaining about the media coverage, and some guy stole a plane and threatened to fly it into the skytower in auckland, classic.