It takes more than a massive outburst to destroy the mammoth star Eta Carinae, one of the brightest known stars in the Milky Way galaxy. About 170 years ago, Eta Carinae erupted, unleashing almost as much energy as a standard supernova explosion.

Yet that powerful blast wasn’t enough to obliterate the star, and astronomers have been searching for clues to explain the outburst ever since. Although they cannot travel back to the mid-1800s to witness the actual eruption, they can watch a rebroadcast of part of the event — courtesy of some wayward light from the explosion. Rather than heading straight... Read more

In the fading afterglow of a supernova explosion, astronomers using NASA’s Hubble Space Telescope have photographed the first image of a surviving companion to a supernova. This is the most compelling evidence that some supernovas originate in double-star systems. The companion to supernova 2001ig’s progenitor star was no innocent bystander to the explosion—it siphoned off almost all of the hydrogen from the doomed star’s stellar envelope. SN 2001ig is categorized as a Type IIb stripped-envelope supernova, which is a relatively rare type of supernova in which most, but not all, of the hydrogen is... Read more

When some people get in the kitchen, they create a delicious meal but leave behind a chaotic mess of splattered food and dirty dishes. Cosmic cookery can be just as messy. While a star can create chemical elements as heavy as iron within its core, anything heavier needs a more powerful source like a stellar explosion or the collision of two neutron stars.

Colliding neutron stars can yield gold, plutonium, and a variety of other elements. Theoretically, they also generate gravitational waves as they spiral together at breakneck speed before merging. The first gravitational wave signal from a... Read more

Albert Einstein reshaped our understanding of the fabric of space. In his general theory of relativity in 1915, he proposed the revolutionary idea that massive objects warp space, due to the effects of gravity. Until that time, Isaac Newton's theory of gravity from two centuries earlier held sway: that space was unchanging. Einstein's theory was experimentally verified four years later when a team led by British astronomer Sir Arthur Eddington measured how much the sun's gravity deflected the image of a background star as its light grazed the sun during a solar eclipse. Astronomers had to wait a... Read more

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 NASA's Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy... Read more

By stretching the capabilities of NASA's Hubble Space Telescope to the limit, astronomers have photographed the close companion of Polaris for the first time. This sequence of images shows that the North Star, Polaris is really a triple star system. These findings were presented today in a press conference at the 207th meeting of the American Astronomical Society in Washington, D.C.