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Consecuencias de la tecnología

It also takes art to restore old paintings that look like scabs...

Fossil Fish Skull (Xiphanctinus audax, Cretaceous) -  Niobrara Formation, Kansas

This sinister looking skull once belonged to a predatory fish that dominated the Western Interior Seaway known as Xiphactinus which was much longer than any bony fish of today. The beast is represented here by just a skull and some post-cranial material, but the point gets across nonetheless.

BLOOMINGTON, Ind. — With crisp resolution to 100 nanometers, the DeltaVision OMX imaging system is considered one of the world’s finest microscope systems. Upon its arrival to Indiana University Bloomington’s Light Microscopy Imaging Center in 2010, researchers quickly renamed it the “OMG” microscope for the amazing images it produced and for its ability to do super-speed imaging of multiple-labeled proteins in cells.

A metaphase epithelial cell stained for microtubules (red), kinetochores (green) and DNA (blue), was the winning image, submitted by IU, in the 2012 GE Healthcare Life Sciences Cell Imaging Competition. The DNA here is fixed in the process of being moved along the microtubules that form the structure of the spindle.

Grasshoppers

images of the Sun captured during the first year of NASA’s Solar Dynamics Observatory (SDO) mission.

Credit: NASA/SDO

Our Weird and Wonderful Galaxy of Black Holes

Black holes are hard to find. Like, really hard to find. They are objects with such strong gravity that light can’t escape them, so we have to rely on clues from their surroundings to find them.

When a star weighing more than 20 times the Sun runs out of fuel, it collapses into a black hole. Scientists estimate that there are tens of millions of these black holes dotted around the Milky Way, but so far we’ve only identified a few dozen. Most of those are found with a star, each circling around the other. Another name for this kind of pair is a binary system.That’s because under the right circumstances material from the star can interact with the black hole, revealing its presence. 

The visualization above shows several of these binary systems found in our Milky Way and its neighboring galaxy. with their relative sizes and orbits to scale. The video even shows each system tilted the way we see it here from our vantage point on Earth. Of course, as our scientists gather more data about these black holes, our understanding of them may change.   

If the star and black hole orbit close enough, the black hole can pull material off of its stellar companion! As the material swirls toward the black hole, it forms a flat ring called an accretion disk. The disk gets very hot and can flare, causing bright bursts of light.

V404 Cygni, depicted above, is a binary system where a star slightly smaller than the Sun orbits a black hole 10 times its mass in just 6.5 days. The black hole distorts the shape of the star and pulls material from its surface. In 2015, V404 Cygni came out of a 25-year slumber, erupting in X-rays that were initially detected by our Swift satellite. In fact, V404 Cygni erupts every couple of decades, perhaps driven by a build-up of material in the outer parts of the accretion disk that eventually rush in. 

In other cases, the black hole’s companion is a giant star with a strong stellar wind. This is like our Sun’s solar wind, but even more powerful. As material rushes out from the companion star, some of it is captured by the black hole’s gravity, forming an accretion disk.

A famous example of a black hole powered by the wind of its companion is Cygnus X-1. In fact, it was the first object to be widely accepted as a black hole! Recent observations estimate that the black hole’s mass could be as much as 20 times that of our Sun. And its stellar companion is no slouch, either. It weighs in at about 40 times the Sun.

We know our galaxy is peppered with black holes of many sizes with an array of stellar partners, but we've only found a small fraction of them so far. Scientists will keep studying the skies to add to our black hole menagerie.

Curious to learn more about black holes? Follow NASA Universe on Twitter and Facebook to keep up with the latest from our scientists and telescopes.

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