Sunday, November 30, 2014

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

Thursday, November 27, 2014

Lonely Stars

Summary: Two missions in 2010 and 2012 saw a rocket launched for a ten minute look at the Extragalactic Background Light (EBL) from above the atmosphere. What is the EBL? Professor Jaime Bock of JPL puts it this way: "It's very faint - but basically the spaces between the stars and galaxies aren't dark. And this is the total light made by stars and galaxies during cosmic history."

Having two separate data collecting missions that looked at different area of the sky allows the scientists to rule out fluctuations due to dust within our solar system. Even with this precaution, there was still extra light. The team believes that based on the brightness and blueness of the EBL, it shows that stars exist outside of galaxies. There might even be just as many stars outside galaxies as inside; it's that bright.

Of course other astronomers are skeptical of this conclusion. They concede it may be possible but are leaving their minds open for new and different possibilities.


BBC News
Science Mag

Thursday, November 20, 2014

Two New Particles

Summary: You read that correctly. Amid all the excitement about the comet landing, researchers at CERN have detected two new particles with the LHCb experiment. These particles were predicted to exist by the quark model but had never been observed. And now we are pleased to introduce yo to Xi_b' and Xi_b*. Super exciting names I know but maybe they will become fancier in the future.
Both of these particles contain one beauty quark, one strange quark, and one down quark. They are more than six times as massive as the proton. They have different spins (a weird quantum mechanical property that describes their angular momentum).

So this is super exciting, because finding more proof for your theories is always good. And now I am off to find out why I have never heard of a beauty quark before. UPDATE: Apparently it is another name for the bottom quark.


Symmetry Mag

Thursday, November 13, 2014

Where no Rover has gone Before

Summary: The landing was a success. Philae has landed on the comet 67P and is now confirmed to be stable. Scientists had been waiting overnight for this confirmation since it was known that the rover had some issues in landing. It actually landed three times due to one of the harpoons failing to attach to the surface. But all is now well and the mission can proceed. One of the main goals is to determine the composition of the comet and use this to learn more about the origins of our Solar System. Especially the question of whether it was from comets that we got our water and the beginnings of life. For a journey that took 10 years, an idea that was born 25 years ago, I hope everyone involved is proud of their success.


BBC News

Wednesday, November 12, 2014

To Boldly Go

Summary: The European Space Agency gave its final 'go' for the Rosetta satellite to release its robot to land on the surface of the comet. This is the first landing attempt on a comet so keep your fingers crossed. Already the mission has has some complications. This final 'go' was delayed because FIND REASON but the mission is going ahead. The team is putting its hopes in the screws, harpoons, and the potentially soft surface of the comet to keep PHILEA stable where it lands. Because of the signal delay, it's too late to do much else but hope.

Update: The rover has successfully landed!

Read more:
BBC News


You can also follow the mission on twitter @Philae2014

Conception art no longer

Summary: The Alma telescope has captured a first image of its kind. A picture of planetary formation. The star is HL Tau and here we can see the protoplanetary disk that has formed around the star. It is out of this that the planets are formed. The dark rings in the image are the paths carved out by new planets being formed. Astronomers were surprised by how quickly the process was taking place; HL Tau is only about a million years old. It was not expected to have planets forming yet. This adjustment in the timescale of planetary formation could have an impact on how we date our own solar system, and now that we know it forms faster than expected, we might train our telescopes on other stars around this age and hope for similar results.

The Mystery of the Cosmic Cloud

Summary: Astronomers have been watching a cosmic cloud heading towards a black hole. They thought they knew what to expect, but once more nature has thrown us a surprise. They had expected some space fireworks but none occurred. As of this news article, scientists don't know what the cause of this is, but some are saying that maybe the gas cloud is not just gas. Others are thinking there is some kind of cloaking somewhere in the system. Either way it is a new mystery for us to find out.


BBC News