astrophysics

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In last week’s episode of It’s Okay To Be Smart, I talked about why the moon orbits the Earth. If you haven’t watched it yet, give it a look. I’ll wait.

There’s some pretty interesting astrophysics keeping the moon orbiting Earth and not getting gobbled up by the sun, eh. But I left one thing out of that video. The moon doesn’t really orbit the Earth. Strictly speaking, the moon and the Earth orbit each other.  

Just like the Earth exerts a gravitational force on the moon, the moon and its mass are “tugging” right back on us. As a result, the two bodies are actually orbiting a point in between, called the barycenter.

If you’ve ever watched pairs figure skating, you’ve seen this in action. When spinning through this move, called a “death spiral”, the two skaters are actually rotating around a barycenter in between their two centers of mass:

This is true of any two orbiting objects, whether it’s a pair of binary stars, a planet and its star, or a planet and its moon(s). You can think of it just like a playground see-saw, with the masses and distance between the two orbiting objects determining where the “balance” point is. 

The Earth/Moon barycenter is about 1,700 km beneath the crust:

Jupiter, despite being more than five times farther from our central star than Earth is, is so massive that its barycenter lies outside of the Sun:

The Earth-Sun barycenter, on the other hand, is effectively in the center of the sun. Our mass is just peanuts compared to that of that huge burning ball of hot gas:

When two orbiting bodies have similar masses and are relatively close to each other, it can be tough to figure out who’s orbiting whom. This is one reason that some astronomers think Pluto and its moon Charon are more of a double-dwarf-planet system:

Scientists use the see-saw physics of barycenters to study planets in distant solar systems, observing these wobbly waltzes to discover planets that we can’t see with telescopes.

The dig deeper into this cool bit of astrophysics, check out this article from my friend Chris Crockett. And cue the Dead or Alive

Hubble Observes One-of-a-Kind Star Nicknamed ‘Nasty’

By Ray Villard

Astronomers using NASA’s Hubble Space Telescope have uncovered surprising new clues about a hefty, rapidly aging star whose behavior has never been seen before in our Milky Way galaxy. In fact, the star is so weird that astronomers have nicknamed it “Nasty 1,” a play on its catalog name of NaSt1. The star may represent a brief transitory stage in the evolution of extremely massive stars.

First discovered several decades ago, Nasty 1 was identified as a Wolf-Rayet star, a rapidly evolving star that is much more massive than our sun. The star loses its hydrogen-filled outer layers quickly, exposing its super-hot and extremely bright helium-burning core.

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A remote galaxy shining with the light of more than 300 trillion suns has been discovered using data from NASA’s Wide-field Infrared Survey Explorer (WISE). The galaxy is the most luminous galaxy found to date and belongs to a new class of objects recently discovered by WISE – extremely luminous infrared galaxies, or ELIRGs.

“We are looking at a very intense phase of galaxy evolution,” said Chao-Wei Tsai of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, lead author of a new report appearing in the May 22 issue of The Astrophysical Journal. “This dazzling light may be from the main growth spurt of the galaxy’s black hole.”

The brilliant galaxy, known as WISE J224607.57-052635.0, may have a behemoth black hole at its belly, gorging itself on gas. Supermassive black holes draw gas and matter into a disk around them, heating the disk to roaring temperatures of millions of degrees and blasting out high-energy, visible, ultraviolet, and X-ray light. The light is blocked by surrounding cocoons of dust. As the dust heats up, it radiates infrared light.

Immense black holes are common at the cores of galaxies, but finding one this big so “far back” in the cosmos is rare. Because light from the galaxy hosting the black hole has traveled 12.5 billion years to reach us, astronomers are seeing the object as it was in the distant past. The black hole was already billions of times the mass of our sun when our universe was only a tenth of its present age of 13.8 billion years.

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The Seagull Nebula
Credit & Copyright: Frank Barrett, Steve Davis

Explanation: Images from two different cameras, a digital SLR and an astronomical CCD camera, are combined in this color starscape. Both cameras made use of the same telescope at the oceanside Winter Star Party in the Florida Keys, appropriately creating this portrait of the Seagull Nebula. The wide view covers a 4x3 degree swath across the plane of the Milky Way, near the direction of Sirius, alpha star of the constellation Canis Major. Of course, the broad region includes objects with other catalog designations: notably NGC 2327 - a compact, dusty emission region with an embedded massive star that forms the bird’s head (above center), andIC 2177 - forming the sweeping arc of the seagull’s wings. Dominated by the reddish glow of atomic hydrogen, the complex of cosmic gas and dust clouds with bright young stars spans over 250 light-years at an estimated 3,800 light-year distance.

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Mostly Mute Monday: The Largest Eruption in the Known Universe

“But this eruption is special, having been going on for hundreds of millions of years, due to the size of the eruption that’s many millions of light years across. If it were caused by accreting matter, it would have had to accrete nearly a billion solar masses worth of material. The combined radio (VLA), visible (Hubble) and X-ray (Chandra) data suggest another interpretation: an ultramassive black hole in excess of 10^10 solar masses powers the outburst.”

What’s causing this monstrosity at the heart of MS 0735.6+7421? Come find out on Mostly Mute Monday.

The Fairy of The Eagle Nebula - M16

“The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined asmythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. The above image in scientifically re-assigned colors was released in 2005 as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.”

Credit: NASA/Hubble/APOD

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How a pair of astrophysicists are defying expectations with a science fashion blog

“People are aware that there’s sort of a galaxy theme out there that sometimes are real images and sometimes they’re just artistic renditions, but I don’t think people are aware of the extent of it and how much that expands into all different types of product lines,” Ash told the Daily Dot.

There’s something for everyone on the blog from everyday wear to runway styles, pricy to affordable products, and options for men, women, and children. Looking through all the options is a lot of fun, but you’ll also learn something. As often as possible, they include the name of what you’re seeing displayed on each product such as a galaxy, along with information about it like its age and why scientists are interested in studying it. Dr. Ash said it’s a “come for the fashion, stay for the science” approach.

[Read more]

Spotting black holes is tricky. Because they don’t give off light, astronomers have a difficult time pinpointing their location. But when a black hole gets close enough to an object, like a star, for example, and begins consuming the object’s mass, the matter that pours into its gravitational clutches can get so hot that it glows and releases energy in the form of X-ray light. The most powerful X-rays are emitted from the hottest material swirling just outside the edge of the black hole. By observing this light with space telescopes, scientists can determine where black holes are hiding in the cosmos. Watch the video to see a black hole in action.

Credit: NASA/Swift

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Mostly Mute Monday: Terrific Tails, For A Time

“As the comet nears the Sun in its orbit, the increased solar radiation vaporizes the ices on its surface, causing ionization, surface disintegration and the development of cometary tails. As it approaches perihelion, its speed increases from just a few km/s all the way up to many hundreds, with the longest tails extending for distances of 500 million kilometers. The various colors come from atomic transitions of various atoms and molecules, such as the green coma coming from the excited diatomic carbon molecule and blue coming from cyanogen.”

What makes cometary tails so brilliant? Find out in pictures, videos and no more than 200 words on this week’s Mostly Mute Monday!

By 2008, Hawking’s hand was too weak to use the clicker. His graduate assistant at the time then devised a switching device called the “cheek switch.” Attached to his glasses, it could detect, via a low infrared beam, when Hawking tensed his cheek muscle. Since then, Hawking has achieved the feat of writing emails, browsing the internet, writing books and speaking using only one muscle. Nevertheless, his ability to communicate continued to decline. By 2011, he managed only about one or two words per minute, so he sent a letter to Moore, saying: “My speech input is very, very slow these days. Is there any way Intel could help?”

MOREHow Intel Gave Stephen Hawking a Voice

anonymous asked:

I read once that Jupiter is a failed star and ended up just shy of enough mass to become one. Is that true? Any other facts about Jupiter you can share? Thanks!

cool idea, Fun Facts About Jupiter!

Formation: You are only partially correct when you say that Jupiter is a nearly failed star. It is a little misleading to say that Jupiter is a failed star because the majority of astronomers believe it formed very differently than the sun. This model of formation is known as the NICE Model (depiction below). Simply put, the NICE Model theorizes that planets formed after the sun in stages. The terrestrial planets formed first, and then the gas giants. The orbiting bodies formed from the accumulation of derbies from the sun’s proto-planetary gas disk:

It is generally though that Jupiter formed in a 2-step process, first with solid matter at the time when the terrestrial planets were forming. When the mass of proto-jupiter became about 10x that of earth, then it’s mass was great enough to begin the second stage of its planetary formation. During this second stage Jupiter gained about 318x the mass of earth very quickly. This quick increase in mass is what solidified Jupiter’s position as the “king” of the planets. (artists concept of young Jupiter):

A Failed Star? (partially correct): When people refer to Jupiter as being a failed star they are most likely referring to the Kelvin-Helmholtz mechanism that we observe in Jupiter. Astronomers use this same mechanism to explain the immense pressure found in the sun. The Mechanism “occurs when the surface of a star or a planet cools. The cooling causes the pressure to drop, and the star or planet shrinks as a result. This compression, in turn, heats up the core of the star/planet.”. This is why Jupiter is “like” a failed star, in fact Jupiter generates more energy through this mechanism than it gets from the sun. However, It simply never had enough mass to begin fussing atoms in and around its core. (this image depicts the balance of pressure that can lead to a heated core & potentially fusion & it’s from my university’s Astrophysics Department!):

Gas Giant? - wrong - Liquid and Metallic Giant: It is a bit of a misnomer that we call the outer planets Gas Giants, when they contain significantly more liquids and metallic-states than gasses. The Only portion of the surface atmosphere is gas, and most of Jupiter is Liquid Metallic Hydrogen and Liquid Molecular Hydrogen. This image shows a breakdown of the interior of the Gas (Liquid) Giants:

Another Nice model of the layering of Jupiter:

The Great Red Spot: Everyone loves the Great Red Spot, So I thought I’d at least mention it. I mean, check out this image taken by the Voyager 1 space craft. 3 earths can fit inside this thing. As far as we know this spot has been here for hundreds of years, or even sense the planet formed. Jupiter’s atmosphere is a complex place and it takes some heavy computing to run simulations to test theories about it. The thought is, the better we understand Jupiter’s Atmosphere (the most complex one that we know of), the better we can understand our own.

And I’ll end with this .gif of the voyager one spacecraft on it’s approach to Jupiter. At the time, this was the farthest humans had ever gone. This was the first time we began to fully explore or solar system. We were taking our first big steps away from home.

Credit: (NICE Model), NASA, Voyager 1, Scientific American, UT Astrophysics - Liquid, UGA Physics and Astronomy,