Category Astronomy/Space

Artist’s impression of a gas giant planet in formation within the protoplanetary disc of a young star. Credit: NASA / JPL

20 years after they were first discovered, ‘hot Jupiters’, gas giant planets that orbit very close to their star, are still enigmatic objects. Using spectropolarimeter ESPaDOnS on the Canada-France-Hawaii Telescope, an international team led by Jean-François Donati (CNRS) has shown that such bodies may only take several million years to migrate close to their newly formed star. The discovery should shed light on how solar systems like – or unlike – our own Solar System form and evolve over the course of their existence.

In the Solar System, rocky planets like the Earth and Mars are found near the Sun, whereas gas giant planets such as Jupiter and Saturn are further awa...

Columbia researchers predict that a pair of converging supermassive black holes in the Virgo constellation will collide sooner than expected. Above, an artist’s conception of a merger. CREDIT (P. Marenfeld/NOAO/AURA/NSF)

Astronomers have provided additional evidence that a pair of closely orbiting black holes deep in the Virgo constellation is causing the rhythmic flashes of light coming from quasar PG 1302-102. Based on calculations of the pair’s mass – together, and relative to each other – the researchers go on to predict a smashup 100,000 years from now, far sooner than previously predicted. The collision will be so powerful it would send a burst of gravitational waves surging through the fabric of space-time itself.

Spiraling together 3...

Artist’s impression of a dusty disc around a red dwarf star. Credit: NASA/JPL-Caltech/T. Pyle (SSC)

Astronomers have found large discs of dust around 2 of the stars, tell-tale signs of planets in the process of forming. “We think the Earth and all the other planets formed from discs like these so it is fascinating to see a potential new solar system evolving,” said the lead researcher Dr Simon Murphy, from the ANU Research School of Astronomy and Astrophysics.

“However, other stars of this age usually don’t have discs any more. The red dwarf discs seem to live longer than those of hotter stars like the Sun. We don’t understand why,” said Dr Murphy. The discovery of objects like these 2 challenges current theories about planet formation...

Illustration of the interior of Saturn’s moon Enceladus showing a global liquid water ocean between its rocky core and icy crust. Thickness of layers shown here is not to scale. Credit: NASA/JPL-Caltech

Researchers found the magnitude of the moon’s very slight wobble, as it orbits Saturn, can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present. The finding implies the fine spray of water vapor, icy particles and simple organic molecules Cassini has observed coming from fractures near the moon’s south pole is being fed by this vast liquid water reservoir.

Previous analysis of Cassini data suggested the presence of a lens-shaped body of water, or sea, underlying the moon’s south polar region...