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A stellar circle of life near Cygnus X-3

22 November 2016 Astronomy Now

A discovery that provides a new way to study how stars form has been captured in a new portrait from NASA’s Chandra X-ray Observatory and the Smithsonian’s Submillimetre Array (SMA). A cloud that is giving birth to stars has been observed to reflect X-rays from Cygnus X-3, a source of X-rays produced by a system where a massive star is slowly being eaten by its companion black hole or neutron star.

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Forming stars in the early universe

21 November 2016 Astronomy Now

The first stars appeared about 100 million years after the Big Bang. When the universe was about 3 billion years old, star formation activity peaked at rates about ten times above current levels. Why this happened, and whether the physical processes back then were different from those today, are among the most pressing questions in astronomy.

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Mysterious flaring X-ray objects discovered in nearby galaxies

26 October 2016 Astronomy Now

Astronomers have found a pair of extraordinary cosmic objects that dramatically burst in X-rays, flaring up to become about a hundred times brighter in less than a minute, before returning to original X-ray levels after about an hour. This discovery may represent a new class of explosive events found in space.

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Hotspots in Cygnus A: an active galactic nucleus

25 October 2016 Astronomy Now

Newly obtained radio images of the dramatic bipolar jets of charged particles being ejected from the nucleus of galaxy Cygnus A were able to resolve hotspots in the jets at the places where they impact the surrounding medium. A bright radio galaxy such as this can beam as much as one trillion solar luminosities of radiation into space at those wavelengths.

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Proxima Centauri might be more Sun-like than we thought

11 October 2016 Astronomy Now

Astronomers recently announced that the nearby star Proxima Centauri hosts an Earth-sized planet in its habitable zone. Proxima Centauri is a small, cool, red dwarf star only one-tenth as massive and one-thousandth as luminous as the Sun. However, new research shows that it is Sun-like in one surprising way: it has a regular cycle of starspots.

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Preparing to study the Epoch of Reionisation

11 October 2016 Astronomy Now

The epoch when the very first stars appeared is a key period of cosmic history. These stars began the manufacture of the chemical elements (those heavier than hydrogen and helium) and their light began the reionisation of the neutral cosmic gas. These stars thus mark the dawn of the universe as we know it today and the start of the so-called Epoch of Reionisation.

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Millisecond pulsars in globular cluster 47 Tucanae

3 October 2016 Astronomy Now

Pulsars are rapidly spinning neutron stars that emit electromagnetic radiation in a sweeping, lighthouse-like beam. They are dramatic, powerful probes of supernovae, their progenitor stars. Astronomers have measured the orbital parameters of four millisecond pulsars in the globular cluster 47 Tucanae and modelled their possible formation and evolution paths.

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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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Nearby Venus-like exoplanet might have oxygen atmosphere

20 August 2016 Astronomy Now

The distant planet GJ 1132b intrigued astronomers when it was discovered last year. Located just 39 light-years from Earth and orbiting its red dwarf star every 1.6 days, new research shows that despite being baked to a temperature of around 232 °C, GJ 1132b might possess a thin, oxygen atmosphere — but no life due to its extreme heat.

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Is Earthly life premature from a cosmic perspective?

1 August 2016 Astronomy Now

The universe is 13.8 billion years old, while our planet formed just 4.5 billion years ago. Some scientists think this time gap means that life on other planets could be billions of years older than ours. However, new theoretical work suggests that present-day life is actually premature from a cosmic perspective.