The important aspect of the solution is so-called plasma flows. A plasma basically is a hot gas, but it is so hot that the atoms have lost their electrons. Normally, electrons swirl around the core of an atom, but when the temperature gets too high, the electrons move so fast that they can escape from their core. At this point you are left with a hot gas of atomic cores and electrons, this is a so-called plasma.

During a solar cycle this plasma flows from the equator towards the poles. At the poles the plasma flows inward and then in the Solar interior, it moves back to the equator. The scientist think that the closer the plasma gets to the poles, the longer a cycle lasts. The laws of physics say that when the cycle gets closer to the poles, i.e. it is longer, the plasma moves slower. This explains why the cycle then lasts longer.

The scientist already predicted back in 2004 that this cycle would last longer and it seems they were right. Apparently, every once in a while the plasma flow reaches closer to the poles. Therefore astronomers should try to monitor the way the solar plasma behaves and thereby improve their knowledge on this behavior. Perhaps then, astronomers are able to fully understand what is going during a Solar cycle and why some last longer than others.

Source: UCAR
Image credit: NASA and UCAR

Using NASA's Solar Dynamics Observatory (SDO) a new eruption on the Sun has been discovered. This eruption, known as a coronal mass ejection, took place on the early morning of August 1st. Such an eruptions blows away tons of so-called plasma. A plasma is a very hot gas, it is even so hot that all the atoms lose their electrons. In 'normal' conditions these atoms swirl around the atomic core, but in a plasma there is so much heat that the atom  'breaks', leaving just an atomic core.

This plasma is erupted and reaches Earth in a few days time. The magnetic field of the Earth catches the plasma particles and directs them to the Earth's poles. Here, the particles collide with atoms of nitrogen and oxygen in the atmosphere, which leaves a glowing neon like stream, also known as aurorae or northern/southern lights. Unfortunately, this eruption did not result in a visible aurora but with a Sun that is waking up, more and more eruptions are expected in the coming time.

The reason why the Sun remained inactive for a longer period of time is still unknown. Many suggestions have been made, but it seems that now the Sun is finally waking up. Still, there is very little understood about the Solar cycle and astronomers are doing their very best to tackle this problem and fit this inactivity in their models.


Source: CFA
Image credit: CFA and Global Warming Art
Movie credit: CFA

IceCub, as the observatory is called, is designed to detect neutrinos. These are particles that are released during the giant supernova explosions that mark the end of massive star's lives (over 10 times the mass of the Sun). Also, black holes tend to send out these neutrinos. It is almost impossible to stop a neutrino. You will need about a light-year of lead to make sure that you will stop an emitted neutrino. As you can see, this makes it very hard to detect neutrinos. Fortunately, the number of neutrinos that are emitted in for instance the core of the Sun, is extremely large. About 6.5 billion pass through the top of your finger every second, just produced by the Sun. This makes the chances of detecting neutrinos a bit better.

When a neutrino happens to interact with a ice particle in the South Pole, it emits a little flash of light, which can be detected by the detector. However, also other particles can cause a small light flash to occur. Very fast moving particles, also released in for instance supernovae, collide with particles in the Earth's atmosphere. The result of this collision can be detected with IceCube. For the neutrino researchers this is just annoying background noise, but for researchers studying cosmic rays this can be very interesting information.

The cosmic-ray-scientists managed to map the entire southern sky and detect the origin of the cosmic rays. It turns out that they are not uniformly spread out over the entire sky. Large regions emit much more cosmic rays than others. This was also seen when the Earth's northern sky was mapped. Perhaps a reasonably young supernova explosion in one of these regions caused the non-uniformity. So although IceCube is not yet doing what it is designed to do, already some interesting science can be done with it.

Source: University of Wisconsin-Madision
Image credit: IceCube collaboration top and bottom

Perhaps you are wondering why it is so special that two planets are that close to each other. Like previously mentioned, such a system can already be found in our Solar system. The main difference between for instance the Earth and Mars, and both recent discovered systems, is that the 'new' planets are much, much heavier than the Earth and Mars. This causes their gravitational attraction toward each other to be about 3 million times larger than for the Earth and Mars. It is even 4 times larger than that between the Sun and the Earth.

If planets like that are formed at such a distance from each other, they would probably kick each other out or collide. However, there must be some other mechanism causing these stars to be so close, because they orbit around a star which is virtually dying and not just forming.

After stars are formed they tend to migrate inward, and the ones that are formed further out migrate faster. At some point two planets can get into so-called resonance, for instance 2:1. This means that one planet is doing exactly 2 orbits, while the other does exactly 1. It turns out that this is an extremely stable situation, making it even possible for two very massive planets to be so close to each other. One of the discovered system is in this resonance with orbital periods of 1.25 and 2.5 years.

When a planet is too rapidly migrating inward, it can 'fly' passed this resonance, and then other resonances turn out to be very stable as well, like 5:3, 3:2 and 4:3. It turns out the other discovered system is in this last resonance, with orbital periods of 1.75 and 2.3 years. So apparently planet formation and migration makes it possible to get very massive planets into an intimate dance.

Source: Caltech
Image credit: NASA top and bottom

NASA's Hubble Space Telescope discovered a giant blue star of about 9 times the mass of the Sun, flying away from the Milky Way at agonizing speeds. About 16 of these hypervelocity stars have been found since 2005, but this is by far the fastest of the group. How do astronomers know that the previous story is the most likely?

First, Hubble managed to observe the velocity and direction of motion of the star. The direction pointed directly away from the Milky Way's center. The measured velocity is impossible for a star to reach under 'normal' circumstances therefore there was the need for something exotic. Imagine a hammer thrower turning and turning with the hammer until at some point he releases the hammer and the hammer flies away. This is more or less what has happened to the system of three stars when it reached the black hole in the Milky Way's center. When the black hole ate on of the three stars which are orbiting around each other, you can compare this to the hammer thrower releasing the hammer. In this case the two stars got flung away at a much higher velocity than they had before.

Using the velocity and the distance to the Milky Way's center, astronomers calculated the star to be flung out about 100 million years ago. The problem here is that a star 9 times as massive than our Sun only lives for about 20 million years. At first, a solution was proposed that the star got flung out from a neighboring galaxy, named the Large Magellanic Cloud which is closer to the star (about 65000 light-years, compared to the 200.000 light-years from the Milky Way's center). However, the new Hubble observations reveal a different origin, namely the Milky Way's center.

This leaves the possibility of two stars that have merged. Stellar evolution can explain for the fact that two stars can merge during their lifetime. One of the stars grows during its evolution and it thereby 'eats' the other star, leaving one large star that appears much younger than it really is. This discovery proves that there are a lot of exotic things happening out there.

Source: Hubblesite.org
Image credit: Hubble top and bottom

When atoms are combined into some sort of two or three dimensional structure, they are called molecules. These molecules can consist of different atoms, like hydrogen and oxygen atoms which make a water molecule, but also similar atoms can combine into a molecule. For instance, three oxygen atoms make an ozone molecule. These large molecules that have recently been detected are of this last kind. They are made up of solely carbon atoms.

One of the two molecules consists of 60 carbon atoms. These atoms are structured in hexagons and pentagons, making a giant football of carbon atoms. Giant of course in terms of molecules, but still almost a billion times smaller than for instance a real football. The other large molecule has a more rugby ball shaped form and consists of 70 carbon atoms.

The molecules are found in a so-called planetary nebula. When a star like the Sun reaches its final stages of its life, it starts to eject its outer layers. These layers form a gas cloud around a much smaller object, known as a white dwarf. This is basically the core of a Sun-like star. This white dwarf shines on the gas, which causes the gas to shine as well in beautiful colors, as you can see on the image on the right. Apparently, at some point large fractions of carbon were ejected by the star. This carbon cools down and combines into all kinds of patterns, like these ball-shaped molecules. The molecules have very distinct chemical and physical properties. aUnderstanding how these molecules were formed in such an environment can help astronomers explain different physical and chemical processes in space.

Source: NASA JPL
Image credit:  NASA