Category Astronomy/Space

This four-panel graphic illustrates how the binary-star system V Hydrae is launching balls of plasma into space. Credit: NASA, ESA, and A. Feild (STScI)

NASA’s 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 it would take only 30 minutes for them to travel from Earth to the moon. 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, V Hydrae, a ed giant, 1,200 light-years away, which has probably shed at least half of its mass into space during its death throes...

Representation of the interior of Enceladus with icy crust, ocean and solid core. ROB researchers think that Dione may also have a subsurface ocean. Credit: NASA/JPL-Caltech/Space Science Institute

A subsurface ocean lies deep within Saturn’s moon Dione, according to new data from the Cassini mission to Saturn. Two other moons of Saturn, Titan and Enceladus, are already known to hide global oceans beneath their icy crusts, but a new study suggests an ocean exists on Dione as well. The researchers of the Royal Observatory of Belgium show gravity data from recent Cassini flybys can be explained if Dione’s crust floats on an ocean 100 kilometers below the surface. The ocean is several tens of kilometers deep and surrounds a large rocky core...

Planetary disk around the star known as TW Hydrae. Credit: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

The dusty disk surrounding star TW Hydrae exhibits circular features that may signal the formation of protoplanets. An astrophysicist argues, however, that the innermost actually points to the impending dispersal of the disk. When the maps appeared at the end of March, experts were electrified. The images revealed an orange-red disk pitted with circular gaps: a detailed portrait of a protoplanetary disk, made up of gas and dust grains, associated with a young star – the kind of structure out of which planets could be expected to form...

Hubble Space Telescope image of supernova 1994D in galaxy NGC 4526 © NASA/ESA

A new math model details a way that dead stars called white dwarfs could detonate, producing a type of explosion that is instrumental to measuring the extreme distances in our universe. The mechanism, described in the Monthly Notices of the Royal Astronomical Society, could improve our understanding of how Type Ia supernovae form. “Type Ia supernovae are extremely important objects in physics, best known for their role in revealing that the expansion of the universe is accelerating,” said Prof. Saavik Ford. “The problem is that people do not agree on exactly how Type Ia supernovae come to be.”

Current research indicates that Type Ia supernova explosions originate from binary star systems – two stars orbiting one...