This is a stellar remnant called Cassiopeia A. It's basically the leftover junk from when a massive star exploded 300 years ago. The explosion was so bright that when it went off, about 11,000 light years away, it would have appeared in Earth's sky.
Source: NASA
Meet Sagittarius A, the supermassive black hole lurking at the center of our galaxy just 26,000 light years away. Scientists have calculated that it weighs more than 4 million times as much as the sun, but is compact enough to fit into the 93-million-mile-long space between the sun and Earth.
Source: NASA
This here is Circinus X-1. Circinus X-1 is a young X-ray binary star system containing a neutron star in orbit with a massive star. The system spits jets of X-rays into the universe, which ricochet off of interstellar dust clouds and create light echoes.
Source: NASA
Centaurus A is the fifth brightest galaxy in the sky. At its heart is a supermassive black hole with the mass of 55 million suns. X-ray and radio jets burst out from the black hole at about half the speed of light. Some of these jets reach into space for millions of lightyears.
Source: NASA
The Crab Nebula is the product of a supernova explosion that could be seen from Earth in 1054 AD. A rapidly spinning neutron star called a pulsar sits inside its stellar guts, spitting out storms of high-energy particles and producing as much energy as 100,000 suns.
Source: NASA
This is Tycho's supernova remnant, named after Danish astronomer Tycho Brahe. When the star exploded in 1572, it was so bright that you could see it in daylight. Four hundred and fifty years later, the explosion is still expanding — at a rate of up to 12 million miles per hour.
Source: NASA
