Great balls of fire! The Hubble Space Telescope has detected superhot blobs of gas, each twice as massive as the planet Mars, being ejected near a dying star. The plasma balls are zooming so fast through space that they would travel from Earth to the moon in 30 minutes. This stellar "cannon fire" has continued once every 8.5 years for at least the past 400 years, astronomers estimate. The fireballs present a puzzle to astronomers because the ejected material could not have been shot out by the host star, called V Hydrae. The star is a bloated red giant, residing 1,200 light-years away, which has... Read more

Two is company, but three might not always be a crowd, at least in space. When astronomers found an extrasolar planet orbiting a neighboring star, a detailed analysis of the data uncovered a third body. But astronomers couldn't definitively identify whether the object was another planet or another star in the system.

Now, nine years later, astronomers have used ultra-sharp images from the Hubble Space Telescope to determine that the system consists of a Saturn-mass planet circling two diminutive, faint stars in a tight orbit around each other. The system, called OGLE-2007-BLG-349, resides 8,000... Read more

The possibility of life on other worlds has fueled humankind's imagination for centuries. Over the past 20 years, the explosion of discoveries of planets orbiting other stars has sparked the search for worlds like Earth that could sustain life. Most of those candidates were found with other telescopes, including NASA's Kepler space observatory. NASA's Hubble Space Telescope has also made some unique contributions to the planet hunt. Astronomers used Hubble, for example, to make the first measurements of the atmospheric composition of extrasolar planets.

Now, astronomers have used Hubble to conduct... Read more

A team of astronomers led by the University of Arizona has directly imaged with the SPHERE instrument on ESO's Very Large Telescope the first planet ever found in a wide orbit inside a triple-star system. The orbit of such a planet had been expected to be unstable, probably resulting in the planet being quickly ejected from the system. But somehow this one survives. This observation of the HD 131399 system suggests that such systems may actually be more common than previously thought. The results will be published online in the journal Science on July 7, 2016. The artist's impression shows a view of... Read more

At the center of the Crab Nebula, located in the constellation Taurus, lies a celestial "beating heart" that is an example of extreme physics in space. The tiny object blasts out blistering pulses of radiation 30 times a second with unbelievable clock-like precision. Astronomers soon figured out that it was the crushed core of an exploded star, called a neutron star, which wildly spins like a blender on puree. The burned-out stellar core can do this without flying apart because it is 10 billion times stronger than steel. This incredible density means that the mass of 1.4 suns has been crushed into a... Read more

In 1936, astronomers observed signs that the young star FU Orionis had begun gobbling material from its surrounding disk of gas and dust with a sudden voraciousness. During a three-month binge, as matter turned into energy, the star became 100 times brighter, heating the disk around it to temperatures of up to 12,000 degrees Fahrenheit. The brightening is the most extreme event of its kind that has been confirmed around a star the size of the sun, and may have implications for how stars and planets form. The intense baking of the star's surrounding disk likely changed its chemistry, permanently... Read more

Water is a hot topic in the study of exoplanets, including "hot Jupiters," whose masses are similar to that of Jupiter, but lie much closer to their parent star than Jupiter is to the sun. They are estimated to be a scorching 2,000 degrees Fahrenheit, meaning any water they host would take the form of water vapor.

Astronomers have found many hot Jupiters with water in their atmospheres, but other hot Jupiters appear to have none. In a new study, scientists used exoplanet data from a single instrument on NASA's Hubble Space Telescope to uniformly characterize a group of 19 hot Jupiters previously... Read more

When astronomer Edwin Hubble discovered nearly 100 years ago that the universe was uniformly expanding in all directions, the finding was a big surprise. Then, in the mid-1990s, another shocker occurred: astronomers found that the expansion rate was accelerating perhaps due to a repulsive property called "dark energy." Now, the latest measurements of our runaway universe suggest that it is expanding faster than astronomers thought. The consequences could be very significant for our understanding of the shadowy contents of our unruly universe. It may mean that dark energy is shoving galaxies away from... Read more

Twenty-six candles grace NASA's Hubble Space Telescope's birthday cake this year, and now one giant space "balloon" will add to the festivities. Just in time for the 26th anniversary of Hubble's launch on April 24, 1990, the telescope has photographed an enormous, balloon-like bubble being blown into space by a super-hot, massive star. Astronomers trained the iconic telescope on this colorful feature, called the Bubble Nebula, or NGC 7635. The bubble is 7 light-years across – about one-and-a-half times the distance from our sun to its nearest stellar neighbor, Alpha Centauri. The Bubble Nebula lies... Read more

Though nearly 2,000 planets have been found around other stars, the light from only a handful of them has ever been collected by the world's most powerful telescopes. Ironically, a lot of them are detected by the shadows they cast, as they pass in front of their parent stars. Follow-up observations measure the planet's feeble, but telltale, gravitational tug on its parent star. Now, Hubble Space Telescope astronomers have been able to pick up the faint infrared glow of a giant planet located 170 light-years away from Earth. Not only is it glowing, but also rhythmically flickering as the planet spins... Read more