But there’s a small but growing list of cases where the two of these approaches disagree about what’s possible. A new paper adds to that list by describing a gas giant planet that orbits a dwarf star, creating a situation where the planet is 25 percent the size of its host—the smallest difference between planet and star yet observed.

Gas giants, as their name implies, are mostly hydrogen and helium. But models of planet formation have suggested that they can only form in systems with a lot of heavier elements around. The idea is that a large core of rocky material has to form quickly, before the star fully ignites and drives off any nearby gas. If the rocky body gets big enough early enough, it can grab enough gas to start a runaway atmospheric accumulation, turning itself into a gas giant.

Studying exosolar systems provides some support for this idea. We can get a sense of how many heavier elements—generically termed metals—were around during planet formation by looking at their presence in the host star. If the star has a high metal content, then the planets probably had access to lots of heavier elements, too. For small, rocky planets, it doesn’t seem to matter how many heavier elements were around, as they’re found at stars with various degrees of metal content. The same is true for super-Earths and Neptune-sized planets.

But not gas giants. These are only found at planets with high metal content, supporting the idea that they require lots of heavy elements to form a big core quickly. This also implies that they should be rare near dwarf stars, since these tiny stars wouldn’t be expected to have a lot of material nearby in the first place. Which brings us to the new discovery.

Next-gen planet hunting

It’s the first planet found by a new project called the Next-Generation Transit Survey (NGTS). Based in Chile, the project is an array of a dozen small telescopes (20cm aperture) hooked up to red-sensitive CCD cameras. An automated system has the telescopes survey a population of about 20,000 stars, looking for periodic dimming caused as planets transit between the star and Earth. The red sensitivity of the cameras allows the system to work with dwarf stars, which produce much redder light than the Sun.

As the host of the first planet discovered with the new hardware, the star picked up the name NGTS-1, with the planet NGTS-1b. It’s close to the host star, completing an orbit in only 2.65 days. Rather than passing directly between the host star and Earth, NGTS-1b only grazes across the edge of the star (envision a planet that, from Earth’s perspective, transits across near one of the star’s poles). Still, that’s enough to provide some sense of its size, and it’s a big one, 1.33 times the radius of Jupiter.

Once it was identified, the researchers imaged it with the HARPS instrument, which determines the planet’s gravitational influence on the host star. This indicated that the planet is 0.8 times the mass of Jupiter. The differences with our local gas giant—larger radius but smaller mass—are probably a result of the small distance between NGTS-1b and its star, which heats and expands the gas of the planet.

By contrast, the star itself is quite small, at only a bit more than half the Sun’s radius. That places it firmly in the M-dwarf category.

All of which makes for a rather unusual combination. NGTS-1b is only the third gas giant found orbiting an M-dwarf—and the most massive one found to date. It also means that, by radius, NGTS-1b is about 23 percent the size of its host star, more than twice the relative size difference between Jupiter and the Sun.

This is confusing

How does a tiny star end up with that much material? That’s less clear. All indications are that NGTS-1 is an old star, which means it formed when heavier elements had even lower abundances than they do today. And, based on the size of the star, it formed under conditions where there wasn’t a lot of material around in the first place. It’s not at all clear how a gas giant formed under those conditions.

There have been some hints that giant planets can form much like stars do, from the direct collapse of a gas cloud. But these tend to be super-Jupiters, objects that are closer to a brown dwarf star than they are to Jupiter. So it’s doubtful that they’re relevant to this system.

It’s worth remembering that there are two other Jupiter-class planets that also orbit M-dwarf stars. So any solution we arrive at to explain NGTS-1b should be general enough to account for these other cases, too.

Which is probably why the authors of the paper argue that it’s best to understand the full extent of the problem first. To do that, we’d want a survey of dwarf stars to get a sense of how frequently they host gas giants. From there, we can start determining the conditions, like heavy element content, that are associated with gas giant formation. With that data in hand, it might be possible to update our models of planet formation to account for these unexpected systems.

NASA said it would use the opportunity to test its ability to tackle the asteroid threat.

Asteroid 2012 TC4, approaching Earth at around 30,000 mph (14 km/s), is set to pass at a distance of about 27,000 miles (43,500 kilometers) on October 12.

Initial estimates released by NASA in July indicated that the asteroid, first discovered five years ago, would pass Earth at a much closer distance – around 4,200 miles.

While the flyby poses no threat to Earth, NASA will use it to test “recovery, characterization and reporting of a potentially hazardous object approaching Earth,” the agency said in August.

“This time we are adding in another layer of effort, using this asteroid flyby to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to finding a potential real asteroid threat.”

NASA estimates put the size of the space rock at 10 to 30 meters in diameter, making it similar to or larger than the Chelyabinsk meteor, which measured about 20 meters in diameter.

The 2013 Chelyabinsk incident in Russia caused damage to hundreds of buildings and blew out thousands of windows. Around 1,200 people sought medical attention after receiving injuries inflicted mainly by flying glass from smashed windows. Over 50 were taken to the hospital, and no deaths were reported.

The space object weighed about 10 tons before entering Earth’s atmosphere, estimates by the Russian Academy of Sciences said at that time. A bright flash from the meteor was seen in the Chelyabinsk, Tyumen, and Sverdlovsk regions, Russia’s Republic of Bashkiria, and in northern Kazakhstan.

Feeling tired? Even if we aren’t tired, why do we yawn if someone else does? Experts at the University of Nottingham have an explanation.

Their study, “A neural basis for contagious yawning”, has been published in the academic journal Current Biology. It is another stage in their research into the underlying biology of neuropsychiatric disorders and their search for new methods of treatment.

Their latest findings show that our ability to resist yawning when someone else near us yawns is limited. And our urge to yawn is increased if we are instructed to resist yawning. But, no matter how hard we try to stifle a yawn, it might change how we yawn but it won’t alter our propensity to yawn. Importantly, they have discovered that the urge to yawn -our propensity for contagious yawning- is individual to each one of us.

Stephen Jackson, Professor of Cognitive Neuroscience, in the School of Psychology, led the multidisciplinary study.

Contagious yawning is triggered involuntarily when we observe another person yawn -it is a common form of echophenomena- the automatic imitation of another’s words (echolalia) or actions (echopraxia). And it’s not just humans who have a propensity for contagious yawning -chimpanzees and dogs do it too.

Georgina Jackson, Professor of Cognitive Neuropsychology in the Institute of Mental Health, said, “This research has shown that the ‘urge’ is increased by trying to stop yourself. Using electrical stimulation we were able to increase excitability and in doing so increase the propensity for contagious yawning. In Tourettes if we could reduce the excitability we might reduce the ticks and that’s what we are working on.”