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Did a low-mass supernova trigger formation of solar system?

29 November 2016 Astronomy Now

About 4.6 billion years ago, a cloud of gas and dust that eventually formed our solar system was disturbed. The ensuing gravitational collapse formed the proto-Sun with a surrounding disc where the planets were born. Now, forensic evidence from meteorites provides conclusive evidence that a low-mass supernova was the trigger.

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What happened after the lights came on in the universe?

15 September 2016 Astronomy Now

The National Science Foundation has approved funding to expand the Hydrogen Epoch of Reionisation Array (HERA) in South Africa. Upgrading the number of antennas from 19 to 240 by the year 2018 will enable HERA to study more clearly the impact of cosmic dawn, the moment a few hundred million years after the Big Bang when the first stars and galaxies blazed awake.

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How black hole jets break out of their galaxies

18 June 2016 Astronomy Now

A computer simulation of the powerful jets generated by supermassive black holes at the centres of the largest galaxies explains why some burst forth as bright beacons visible across the universe, while others fall apart and never pierce the halo of the galaxy. A jet’s hot ionised gas is propelled by the twisting magnetic fields of the central rotating black hole.

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Hubble finds universe is expanding faster than expected

2 June 2016 Astronomy Now

When 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 “dark energy.” Now, the latest measurements of our runaway universe suggest that it is expanding faster than astronomers thought.

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Kepler-223 star system has four mini-Neptunes in synchronised orbits

12 May 2016 Astronomy Now

A four-planet system orbiting the star Kepler-223 in the constellation Cygnus is actually a rarity: Its planets, all miniature Neptunes nestled close to the star, are orbiting in a unique resonance that has been locked in for billions of years. For every three orbits of the outermost planet, the second orbits four times, the third six times and the innermost eight times.

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Astronomers glimpse supernova shockwave for the first time

22 March 2016 Astronomy Now

Astronomers have captured the earliest minutes of two exploding stars and for the first time seen a shockwave generated by a star’s collapsing core. The international team found a shockwave only in the smaller supernova — a finding that will help them understand these complex explosions that create many of the elements that make up the Earth and solar system.

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Watching an exoplanet in motion around a distant star

17 September 2015 Astronomy Now

A team of astronomers, using the Gemini Planet Imager (GPI) on the Gemini South telescope in Chile, has given us our best view yet of an exoplanet moving in its orbit around a distant star. A series of images captured between November 2013 and April 2015 shows the exoplanet β Pictoris b as it moves through 1½ years of its 22-year orbital period.

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Astronomers discover nearby Jupiter-like exoplanet enshrouded in methane

13 August 2015 Astronomy Now

The Gemini Planet Imager instrument has discovered and photographed its first planet. Dubbed 51 Eridani b, the body is a methane-enshrouded gas giant that is the most Jupiter-like exoplanet ever directly imaged, in a planetary system just 20 million years old. It may hold the key to understanding how large planets form in the swirling accretion discs around stars.