Death Stars

There are hundreds of young stars and protostars that are found in the Orion Nebula. For many of these stars, the material around them will eventually form planets. 

Sun-like stars are often born in crowded stellar nurseries like the Orion Nebula. Over millions of years, dust and pockets of gas collect and form into larger, denser bodies. Many will grow into star systems with orbiting planets. However, not all stars have planets, and new research shows one reason why this is true.

 

For the first time, evidence has been found that protoplanetary disks vanished under the intense glow of a nearby massive star. A new study shows that other stars will have all of their planet-forming dust and gas blasted away by “Death Stars”. 

The types of stars are knows as O-type stars.These O-type stars that are hundreds of times more luminous than our Sun, reduce nearby protoplanetary disks. They heat up the gas which breaks it up, and it is swept away, only leaving behind a fraction of the material necessary to create a planet the size of Jupiter 

Sources:

https://public.nrao.edu/news/pressreleases/death-stars-in-orion

http://www.universetoday.com/110271/death-stars-caught-blasting-proto-planets/

Andromeda Galaxy

Our eyes are only able to see a very small portion of the electromagnetic spectrum, so scientists have needed to find different ways of gather information on the wavelengths that we can’t detect. Each different wavelength is able to provide different types of data regarding the structure, composition, or temperature the galaxy or any object being studied.

These images show Andromeda Galaxy in different wavelengths. The Andromeda Galaxy is about twice as big as the Milky Way. It is about 2.5 million light years away from us but it is moving towards us at 250 mph and in about 3 billion years, it will collide with our galaxy.

Sources: 

http://en.wikipedia.org/wiki/Andromeda_Galaxy

Gravitational Waves

Einstein had predicted gravitational waves as part of his General Theory of Relativity. Now, almost a century later, the first detection of a gravitational wave has been reported. It was announced today by the Harvard-Smithsonian Center for Astrophysics. The Plank space observatory has been studying the CMB since 2009, and astronomers hoped it would be able to provide the evidence, but the results came from the Background Imaging of Cosmic Extragalactic Polarization (BICEP) detector located at the South Pole.

The Cosmic Microwave Background (CMB) is the left over radiation from a four hundred thousand years after the Big Bang. In the mid 1990s astrophysicists proposed that the polarization of the CMB could provide evidence for gravitational waves from the birth of the universe

The discovery of the CMB polarization by gravitational wave settles the debate over whether the early universe was inflationary.  An inflationary period would produce larger gravitational waves than if there was no inflationary period. But even most inflationary models do not predict a gravitational wave large and polarizing enough to be detected by BICEP. The signal from BICEP is so strong, that it makes many of the inflationary models of the early universe unsupported, and completely contradicts the non-inflationary versions.

The paper can be read here http://bicepkeck.org/b2_respap_arxiv_v1.pdf

Sources:
http://news.yahoo.com/major-discovery-smoking-gun-universes-incredible-big-bang-145912987.html

http://www.space.com/25078-universe-inflation-gravitational-waves-discovery.html

http://en.wikipedia.org/wiki/Cosmic_microwave_background

Hypergiant HR 5171

Using the Very Large Telescope, scientists have discovered a hypergiant star is actually the largest yellow star ever found. HR 5171 is one of the largest starts ever discovered! It’s even 50 percent larger than the famous red supergiant, Betelgeuse.

Scientists and amateur observers have been watching the yellow hypergiant star HR 5171 A for more than 60 years. Using the European Southern Observatory’s Very Large Telescope Interferometer, an international team of researchers have discovered that the yellow hypergiant is even bigger than expected: It’s 1,300 times the diameter of the Sun and about a million times brighter. Doing simple calculations, we see that the radius would of HR 5171is 904,150,000 km, which is approximately 6.04 AU. The distance from the Sun to Jupiter is 5.2 AU, so that means that if HR 5171 was at the center of our solar system it would reach somewhere in between Jupiter and Saturn!

Only about a dozen of these yellow hypergiants are known in our galaxy, for example Rho Cassiopeiae. They are some of the biggest, brightest stars, and we are seeing them while they are unstable and rapidly changing stage of their lives. This one was found during a very short-lived phase. HR5171 is a massive interacting binary star, which is a double-star system where both stars are still in contact.

Although its is nearly 12,000 light years away from Earth, it is visible to the naked eye. It can be found in the constellation Centaurus.

Sources:
http://www.eso.org/public/news/eso1409/

http://rt.com/news/sun-yellow-star-biggest-622/

http://en.wikipedia.org/wiki/Interacting_binary_star

The Kepler space telescope has found a "weird, wobbly" planet that spins wildly on its axis like a child's top. Every 66 days, it rotates around a pair of red and orange dwarf stars, and even that orbit seems to wobble. The new planet, called Kepler-413b, has a spin axis that was found to vary by up to 30 degrees over 11 years. This means that the planet experiences extreme variations in its cycle of seasons. That is very different to Earth's rotational precession which is a only 23.5 degrees over 26,000 years. 

Kepler-413b is located about 2,300 light-years away in the constellation Cygnus. It isn't suitable for life because since it orbits to close to its stars, it makes it too hot to sustain liquid water. It's also known as a "super Neptune," which is just a gas giant with no place to stand and it is 65 Earth masses.

Astronomers are trying to explain this behavior. Some of the explanations are that there could be other planets that affect the orbit or there could be another star that is has a gravitational influence on it. 

Sources: 

http://spaceindustrynews.com/nasa-spots-and-incredibly-wobbly-super-neptune-planet-kepler-413b/4162/

http://www.latimes.com/science/sciencenow/la-sci-sn-planet-wobble-kepler-413b-20140204,0,7930803.story#axzz2tBYuBvmn

Black Hole theory wrong? Hawk-ward!

Professor Stephen Hawking posted a paper, "Information Preservation and Weather Forecasting for Black Holes", in which he claimed that our current understanding of black holes is wrong. He states that the traditional notion of a black hole's "event horizon" from which nothing can escape, not even light, conflicts with quantum physics. If he is correct, physicists will have to redefine black holes entirely.

According to Hawking, "The absence of event horizons mean there are no black holes - in the sense of regimes from which light can't escape to infinite". Hawking believes that rather than an event horizon, black holes have an "apparent horizon". This apparent horizon only holds matter, light, and energy temporarily, and it is eventually released. This new idea would work with both quantum theory and general relativity's predictions for black holes. It would also solve the "black hole firewall paradox" that has been troubling physicists for the last two years.

His paper hasn't been published or peer reviewed yet. Scientists usually wait until papers have gone through a peer review process before taking notice, but since the author is the famous Professor Stephen Hawking, things are a little different. He has studied black holes for decades. He was the first to challenge the belief that nothing can escape a black hole and he theorized that black holes have a type of black body radiation, called "Hawking radiation".

We will have to wait and see how physicists will revise the theory of black holes. You can read Hawking's paper online on this link: http://arxiv.org/abs/1401.5761

Here's a cool video of Einstein and Hawking in a rap battle : http://www.youtube.com/watch?v=zn7-fVtT16k


Sources:

http://arxiv.org/abs/1401.5761

http://www.independent.co.uk/news/science/stephen-hawking-there-are-no-black-holes-9085016.html

http://en.wikipedia.org/wiki/Hawking_radiation

New Horizons: Pluto-Kuiper Belt Mission

NASA's New Horizons spacecraft mission is currently on its way to the dwarf planet Pluto, and is over halfway there. The probe lifted off on January 19, 2006 from Cape Canaveral Air Force Station, Florida on an Atlas rocket. It will fly by and study Pluto and its moons, Charon, Nix, Hydra, Kerberos, and Styx around July 14, 2015. After that, NASA plans to attempt flybys of one or more other Kuiper belt objects, if a suitable target can be located. 

The spacecraft passed by Jupiter and its moons around February 2007 to give it a boost in its velocity. This technique is called gravity assist and it is done by the gravitational field of a planet. It works by both the gravitational field of the planet and the motion of the planet orbiting the Sun. If the spacecraft flies along the planets orbit around the Sun, it will gain some of the planet's orbital energy. The total kinetic energy remains constant, so while the planet loses some, the spacecraft gains some of it and this is what causes the increase in speed. This is a very clever trick because it does not require any fuel to give it a boost! This is how New Horizon will get to Pluto.

New Horizon trajectory as it passes Jupiter

While New Horizon passed Jupiter, NASA took the opportunity to take data and study Jupiter and its moons. It took pictures of Jupiter's surface and the data was used to analyze the atmosphere and composition and structure of its clouds. This 4 month period of observation also helped to test the equipment and served as a test run for the Pluto encounter.

The main goal of this mission is to study Pluto and its moons. Scientists want to understand the composition and conditions of the atmosphere and the structure of the surface of Pluto and its moons. New Horizon is expected to arrive at Pluto in July 2015

Sources:

http://pluto.jhuapl.edu/index.php

http://en.wikipedia.org/wiki/New_Horizons

http://www2.jpl.nasa.gov/basics/grav/primer.php