Seven Dwarfs, err, Planets

Summary: In a brand new press release from NASA, the agency has announced a discovery of seven Earth-sized planets, in the habitable-zone, around a single star. This is the largest star system with such properties and I am excited. The discovery was made by the Spitzer Space Telescope and follow up with ground based observatories.

To be fair, only three of these planets are definitely in the habitable zone, but with the right atmospheric conditions, all seven are likely to have liquid water. This exoplanet system has been called TRAPPIST-1 and the densities show that all planets are likely to be rocky planets like the inner planets of our own solar system. Unlike our sun, this star is an ultra-cool dwarf star that allows all of these planets to be closer to their star than Mercury is to our star. With all of these planets being so close, it is possible that an individual standing on the surface of one planet may be able to look up at the sky and see geological features on the neighboring planet without the aid of binoculars. We can barely do this with our own moon despite how close it is.

If you wanted to visit this system, it is relatively close to us, at only 40 light-years away in the constellation of Aquarius. But until we invent better spacecraft we can only take advantage of the nearness by turning more telescopes to the system. Hubble and Kepler are doing follow-up observations and, when it launches, the James Webb Space Telescope will collect further data.

NASA press release
360 VR of exoplanet surface
Nature

Artist's conception of the system based on known diameters, masses, and orbital distances, NASA JPL, Caltech

Double Black Hole Hails Discovery of Gravity Waves

Summary: It's the announcement of a discovery you didn't know you were waiting for. The detection of gravitational waves. It sounds weird, of course, but Einstein was onto something big when he was working on his theory of general relativity. Similar to a ball warping the surface of a rubber sheet, or a kayak being thrown into the water, large objects in outer space warp the fabric of the four dimensional spacetime that we live in.

When this happens, gravitational waves ripple through space and expand or contract the space around them. These waves have been undetectable until now. It is thanks to the LIGO interferometer that we can detect these faint waves in the universe. These waves are understandably hard to detect, the measurements are on a scale less than a width of an atom. They were able to detect this thanks to a double black hole.

Quite deservedly, the scientists involved are quite proud of their work. As this is both the first detection of gravity waves and the first direct detection of a black hole in addition to being confirmation of general relativity, they are confident that there is a Nobel Prize in their future and I am inclined to agree.

Either way, it is an exciting breakthrough in astronomy and one that I am excited to have as I enter the field.


APS Article
BBC News
Nature
SciShow

Strong Forces Between Antipotons

Summary: Woah, a story about antimatter on an antimatter blog! Finally.

Unlike a lot of other anitmatter and particle physics news, this does not come to us from CERN but rather from in Relativistic Heavy Ion Collider (RHIC) at Brookhaven in New York. Here physicists were able to measure the interactions between antiprotons. It seems like it is also the strong force, an attractive force, that holds the antiprotons together just as it also holds the protons together. This is just one more way in which protons and antiprotons are essentially the same, the exception of their opposite charge. Because of the similarity scientists can rule this out as a possible explanation for the matter/antimatter asymmetry in the universe today.

BBC News
Nature

Tractor Beams made of Sound

Summary: It may not be quite the tractor beam that you expect from a scifi show like "Star Trek," but we are getting closer. The way these scientists have developed relies on the pressure of sound waves. Instead of trying to create a concentrated beam that holds a particle, they instead create a vacuum of space, bounded by high intensity waves all around it. Then  by adjusting the boundaries, they are able to move the trapped particle. Currently the capabilities of the design only apply up to pea-sized particles at less than 40cm away.

Despite the apparent 3D nature of the holding pattern, it only requires a loudspeaker on one side of the particle. For the researchers, this means that it could be applied in the medical field for drug delivery. For those of us thinking of the future, this means that tractor beams on spaceships may be possible in a distant future. (Which the scientists did prove would work on a scaled down model.)


BBC News
Nature

Symmetry of Nuclei

Summary: Finally, some news about antimatter! Scientists at the LHC who are working on ALICE, have been able to more precisely measure the nuclei of particles and their antiparticles. Happily they discovered that there is fundamental symmetry with their charge, parity, and time.

The ALICE experiment smashes particles together that create nuclei and antinuclei at the same rate which allow the scientists to study them easier.


Quarks to Quasars
Nature

The Case of the Strangled Galaxies

Summary: Galaxies are considered dead when they no longer are producing new stars. It is still unclear what causes this process but what astronomers do now know is the most common time scale of them dying -- approximately four billion years. Astronomers are calling this process strangulation.

Astronomers are able to tell how quickly the galaxy died based on the metal content remaining in the galaxy. The more stars that are being formed in a galaxy, the more metal content is seen. The way it works is simple. If a galaxy dies quickly and quite violently (for instance if the cool gas that fuels the star formation is suddenly ripped away), then the stars immediately stop producing and the metal content remains the same. But if the galaxy if cut off from the supply of cool gas but still continues to produce stars, using up the last of the supply, the metal content in the galaxy grows and grows until it "suffocates".

The difference was seen when comparing the spectra of light emitted by red, passive galaxies and blue, star-forming galaxies. With the data from Sloan they were able to see that the dead galaxies were, on average, four billion years older than the active galaxies. This is consistent with the amount of time the astronomers had calculated it would take to burn of the remaining amount of gas supply whilst strangling to death.

While the astronomers are now confident that death by strangulation is the most common way a galaxy meets it's ultimate end, it is still not clear what causes this. The most likely suspect at this point in time seems to be overcrowding which would lead to a greater probability of disruption to the gas supply, but this would need further investigation.



BBC News
Nature

Using the Eye of Sauron to see Great Distances

Summary: Two of my geeky obsessions have overlapped at long last. And in an exciting way too. As we strive to learn more about the beginnings of our universe, astronomers need new ways to measure distances to distant galaxies. The galaxy NGC4151, nicknamed The Eye of Sauron, has provided that.
The method relies on measuring the size of the supermassive black holes found at the center of all big galaxies. These black holes swallow up a huge about of gas and end up spewing emissions back out to become an AGN. The hot dust becomes a ring around the black hole which the astronomers used for measuring distance. By measuring the time delay between the emission of light from very close to the black hole and the infrared emission of the dust ring, we are able to know the distance the light has had to travel from the black hole to the ring.
Knowing the physical size and the apparent size of the ring means astronomers have a new method of measuring distance with only a 10% uncertainty. Not the most precise method we have but it is one that can be easily applied to many other galaxies out there.


AlphaGalileo
Nature

Two New Discoveries in the Solar System

There's not too much to say about these. The first one is an asteroid that has been discovered to have it's own rings. This is the first asteroid we have found that has its own ring system.

BBC News
Nature


The second one is a new dwarf planet that has been discovered outside of Pluto's orbit. There's two main theories on its formation, but it has still yet to be officially confirmed.

BBC News
Nature

No Black Holes?

Summary: In an article I cannot quite wrap my head around, Stephen Hawking has now proposed that the black holes we know (well, sorta know) and love, don't actually exist. I don't really understand the article but it seems to me that he is proposing a different definition of black holes. That they still exist, but just need to be defined differently. If anyone can summarize the article better, please leave a summary in the comments.


Nature

The Future of African Astronomy

Summary: Due to a new radio telescope array in Africa, scientists are predicting a burst of enthusiasm for my favorite branch of physics. Right now, the challenge is to nurture the African scientists and make sure it is not just a flood of US scientists who happen to be in Africa. A long-term relationship with the country needs to be built up. South Africa is also hoping to use this project to inspire future generations of scientists in their country to boost their country's economy and world standing.

The telescope array will contain 3,000 radio dishes and will be able to scan the sky faster than any previous instruments of the kind. The headquarters of this project is in South Africa who took the other countries by surprise when they won the bid. They won the scientific community with clear skies and legislation that strictly limits the amount of radio noise in that area surrounding the telescope which will make the data incredibly accurate and meaningful.


Nature
Square Kilometer Array (SKA)

Lava World

Summary: The data from Kepler has revealed another planet that would be brilliant inspiration of any sci-fi novel you are trying to write. This planet, Kepler 78b, is mostly rock and iron but extremely close to its host star. This, paired with the theory that it is tidally locked, means that it is reasonable to assume that that side of the planet is completely molten. With that side of the planet being between 2,000C and 2,800C, it is obviously too hot to support life. It is uncertain what the temperatures on the other side of the planet might be or how far down the molten layer goes. This planet is also an enigma because "according to current theories of planet formation, Kepler 78b could not have formed so close to its star, nor could it have moved there." As a bonus, it is also doomed to be slowly pulled closer and closer into it's star which will proceed to rip it apart.


BBC News
Nature

The Universe's Violent Youth

Summary: Scientists at the Kavli Institute for Particle Astrophysics and Cosmology found new evidence to support the prevalent theory of the universe having a violent stage mare than 10 billion years ago that was responsible for the initial creation of heavy elements. Using the Suzaku satellite they saw an even spread of iron between the galaxies. This means that iron was present in the intergalactic gas even before the Perseus cluster was formed; an observation which they speculate holds true for more than just this cluster. This would put the creation of these elements between 10 to 12 billion years ago, during a time of intense star formation and energetic black holes. Most of this iron was created by Type Ia supernovae that then rocketed out their material into space.

Symmetry

Nature

Oversized Black Hole

Summary: Scientists have found a enormous black hole in the middle of a relatively small galaxy. It's been calculated that the black hole accounts for about 15% of the galaxies mass. This is way more than is typical. Scientist are guessing that it was formed a long time ago and then nothing else really started to form. Check out the details below.



Nature: http://www.nature.com/nature/journal/v491/n7426/full/nature11592.html
BBC News: http://www.bbc.co.uk/news/science-environment-20528137

New Planets

Summary: Kepler has recently discovered an Earth-size planet and two smaller planets that may be the charred remains of planets.

BBC News:
http://www.bbc.co.uk/news/science-environment-16268950
http://www.bbc.co.uk/news/science-environment-16279016

Nature:
http://www.nature.com/nature/journal/vnfv/ncurrent/full/nature10780.html