White dwarf star

Just a reminder
  • Snow White and the Seven Dwarfs went completely overbudget, and no-one believed anyone would want a full-length animated film. It created a whole new genre.
  • George Lucas thought that Star Wars was going to be such a failure, he went on holiday rather than attend the premiere. It has become one of the most influential film sagas in film history
  • The Lion King was listed as a ‘B’ movie by Disney, and thus less effort was placed on it. It became Disney’s highest grossing film until 2013.
  • Beauty and the Beast had multiple time and money constraints, and was in “development hell” since the 1930′s. It became the first animated feature to win a Golden Globe for Best Picture - Musical or Comedy, Disney’s first Oscar nominated film for Best Picture since Mary Poppins, and was the reason the Academy created the ‘Best Animated Picture’ category.
  • Frozen was stuck in “development hell” since Walt Disney was alive, and had multiple redrafts and script rewrites, and a few questioned whether it would be successful. It became the highest grossing animated film of all time, broke box office records across the world, became Disney’s first movie since Tarzan to win an Oscar (and won two) and became the first Disney movie (not including Pixar) to win the Golden Globe for Best Animated Feature Film.

Just because a project may be taking longer than you had hoped, or you have had to redo it multiple times, or you don’t think it will be a success doesn’t mean your project isn’t good. Sometimes our most successful projects are the most surprising ones

Don’t give up!

Wispy remains of a supernova explosion hide a possible ‘survivor.’ Of all the varieties of exploding stars, the ones called Type Ia are perhaps the most intriguing. Their predictable brightness lets astronomers measure the expansion of the universe, which led to the discovery of dark energy. Yet the cause of these supernovae remains a mystery. Do they happen when two white dwarf stars collide? Or does a single white dwarf gorge on gases stolen from a companion star until bursting? If the second theory is true, the normal star should survive. Astronomers used the Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy called the Large Magellanic Cloud. They found a sun-like star that showed signs of being associated with the supernova. Further investigations will be needed to learn if this star is truly the culprit behind a white dwarf’s fiery demise.

 This supernova remnant is located 160,000 light-years from Earth. The actual supernova remnant is the irregular shaped dust cloud, at the upper center of the image. The gas in the lower half of the image and the dense concentration of stars in the lower left are the outskirts of a star cluster.

Image credit: NASA, ESA and H.-Y. Chu (Academia Sinica, Taipei)

Symbiotic R Aquarii : A long recognized naked-eye variable star, R Aquarii is actually an interacting binary star system, two stars that seem to have a close, symbiotic relationship. About 710 light years away, it consists of a cool red giant star and hot, dense white dwarf star in mutual orbit around their common center of mass. The binary systems visible light is dominated by the red giant, itself a Mira-type long period variable star. But material in cool giant stars extended envelope is pulled by gravity onto the surface of the smaller, denser white dwarf, eventually triggering a thermonuclear explosion and blasting material into space. Optical image data . The composite field of view is less that a light-year across at the estimated distance of R Aquarii. via NASA

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When Will The First Star Go Dark?

“I’m sorry to disappoint you, but there aren’t any black dwarfs around today. The Universe is simply far too young for it. In fact, the coolest white dwarfs have, to the best of our estimates, lost less than 0.2% of their total heat since the very first ones were created in this Universe. For a white dwarf created at 20,000 K, that means its temperature is still at least 19,960 K, telling us we’ve got a terribly long way to go, if we’re waiting for a true dark star.”

Stars live for a variety of ages, from just a million or two years for some to tens of trillions of years for others. But even after a star has run out of its fuel and died, its stellar corpse continues to shine on. Neutron stars and white dwarfs are both extremely massive, but very small in volume compared to a star. As a result, they cool very slowly, so slow that a single one has not yet gone dark in all the Universe. So how long will it take, and who will get there first: neutron stars or white dwarfs? Believe it or not, there’s still enough uncertainty about how neutron stars cool, mostly due to uncertainties in neutrino physics, that we think we know the answer to be white dwarfs – and 10^14 or 10^15 years – but we’re not entirely sure!

Come find out what we know about finding the first truly dark star in the Universe today.

This ultraviolet image from NASA Galaxy Evolution Explorer is of the planetary nebula NGC 7293 also known as the Helix Nebula. It is the nearest example of what happens to a star, like our own Sun, as it approaches the end of its life when it runs out of fuel, expels gas outward and evolves into a much hotter, smaller and denser white dwarf star. 

The Red Spider Planetary Nebula : Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds emanating from the central stars, visible in the center, have been measured in excess of 1000 kilometers per second. These winds expand the nebula, flow along the nebulas walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the above representative-color picture by the Hubble Space Telescope. The Red Spider Nebula lies toward the constellation of the Archer . Its distance is not well known but has been estimated by some to be about 4,000 light-years. via NASA

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Ask Ethan: Why Do Stars Come In Different Sizes?

“Why can suns grow to… many different sizes? That is, ranging from somewhat larger [than] Jupiter up to suns exceeding Jupiter’s orbit?”

“Bigger mass makes a bigger star,” you might be inclined to say. The smallest stars in size should be small because they have the least amount of material in them, while the largest ones of all are the largest because they’ve got the most material to make stars out of. And that’s a tempting explanation, but it doesn’t account for either the smallest stars or the largest ones in the Universe. As it turns out, neutron stars and white dwarfs are almost all larger in mass than our own Sun is, and yet the Sun is hundreds or even many thousands of times larger than they are. The most massive star known is only 30 times the physical size of our Sun, while the largest star of all is nearly 2,000 times our Sun’s size. As it turns out, there’s much, much more at play than mass alone.

Why do stars really come in different sizes, and how do we even know how big a star is at all? Find out on this week’s Ask Ethan!

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We just got our first complete look at an exploding white dwarf star

For the first time ever, scientists have captured the full process of a nova explosion — the moments before, during and after the blast.

Nova explosions are different from supernovas because the star isn’t completely destroyed. Novas happen in two-star systems, when a white dwarf star has been sucking in mostly hydrogen gas from a close neighboring star. The extra hydrogen explodes, but the explosion only happens on the star’s surface. Apparently, white dwarfs have something in common with bears.

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Zombie white dwarf star caught destroying an orbiting planet    

More than 570 light years away in the constellation Virgo, a disintegrating planet orbits around a white dwarf — the leftovers of a yellow star after it died. The cause of the planet’s demise is the zombie star itself; the white dwarf is extremely dense, and its enormous gravitational pull is tearing the rock apart, creating an enormous cloud of dust and debris that follows the planet on its orbit.

This dance of the dead was observed by NASA’s Kepler spacecraft last year. The discovery of the planetary system is the first of its kind. It helps to confirm what many scientists have suspected for years: that planets can actually orbit white dwarfs.

— Loren Grush for The Verge

Requested by @kittycatpasta11

Pew! It looks like Nebby escaped the bag again, and came straight for our blog! Today we have the pleasure of examining everyone’s favorite bag-defying rebel, Nebby Cosmog. Cosmog is the “Nebula Pokémon”, so naturally we should talk about nebulas.

The word “nebula” comes from the Latin word for “cloud”, which is a pretty good description of what a nebula is. A nebula is cloud in space: but instead of being made of water like clouds in Earth’s atmosphere, they’re made of stuff like hydrogen, helium, ionized gas, and dust. There are four main types of nebulae, so if we want to learn about Cosmog we first need to figure out which kind of nebula it is.

Planetary nebula are sometimes formed when a star dies,  gently puffing out its outer layers until all that’s left is the core of the star, which usually becomes a white dwarf star itself (which you can see as the central dot in all of these images). The central star pumps light energy into the nebula, which causes it to glow the bright colors.

Supernova Remnants, on the other hand, are formed when a star dies violently. When a massive star runs out of fuel to burn, it will explode in a supernova, tearing itself apart at speeds of over 30,000 m/s. A neutron star or black hole is left in the center, and what is left of the star in the explosion becomes the nebula.

The third kind of nebula is called a Dark Nebula or an Absorption Nebula, obecause it “absorbs” and blocks out light behind it. They’re made of molecules, such as molecular hydrogen, nitrogen, carbon monoxide – which is why they’re also called molecular clouds. These are the coldest, and most dense clouds in space. In fact, they are the only nebula dense enough to collapse into stars, forming new baby stars as they collapse.

The last of nebula is called an HII region. HII is astronomy jargon for ionized hydrogen–in other words, just a proton. These clouds are made of mostly protons. HII regions are typically larger than the other nebulas we’ve talked about, and often just had a lot of recent star formation  in them: they were molecular clouds, but since they just formed new baby stars, they’re full of new energy. The baby stars add so much heat and light into the nebula that the molecules are ripped apart once again, leaving mostly protons.

Cosmog, of course, is much smaller than actual nebula. But, we know Cosmog evolves into Cosmoem, the “Protostar Pokémon”, which means that Cosmog must be closest to a star-forming nebula, or a molecular cloud. You can even see the little glowing spots in Cosmog’s arm where it’s starting to form stars.

Cosmog is a dark nebula made up of molecular hydrogen and other molecules, collapsing to form new stars.