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