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Hottest white dwarf discovered in our Galaxy

29 November 2015 Astronomy Now

With a temperature of 250,000 °C — 45 times that at the surface of our Sun — astronomers believe that this dying star in the outskirts of the Milky Way may have peaked at 400,000 °C a thousand years ago. The researchers were also the first to observe an intergalactic gas cloud moving towards the Milky Way — indicating that galaxies collect fresh material from deep space, which they can use to make new stars.

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Asteroid ripped apart to form star’s glowing ring system

11 November 2015 Astronomy Now

The remains of a fatal interaction between a dead star and its asteroid supper have been observed in detail for the first time. An international team of astronomers used the Very Large Telescope at ESO’s Paranal Observatory in Chile and other observatories to study the shattered remains of an asteroid around a stellar remnant — a white dwarf.

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White dwarf “Death Star” seen destroying a planet

21 October 2015 Astronomy Now

The Death Star of the movie Star Wars may be fictional, but planetary destruction is real. Astronomers announced today that they have spotted a large, rocky object disintegrating in its death spiral around a distant white dwarf star. The discovery also confirms a long-standing theory behind the source of white dwarf “pollution” by metals.

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Hubble sees an ageing star wave goodbye

9 October 2015 Astronomy Now

When stars that are around the mass of the Sun reach their final stages of life, they shed their outer layers into space, which appear as glowing clouds of gas called planetary nebulae. In the case of Menzel 2, otherwise known as PK 329-02.2, the nebula forms a winding blue cloud that perfectly aligns with two stars at its centre.

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Discovery of white dwarf companions of millisecond pulsars

4 October 2015 Astronomy Now

When a massive star ends its life in a spectacular supernova explosion, it can leave behind a rapidly spinning neutron star with a period of 1-10 milliseconds. Such objects that emit electromagnetic radiation in a lighthouse-like beam sweeping past the Earth are known as millisecond pulsars. CfA astronomers have identified white dwarf companions of two more millisecond pulsars in the spectacular globular cluster 47 Tucanae.

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Pulsar study suggests force of gravity constant throughout universe

7 August 2015 Astronomy Now

Gravity, one of the four fundamental forces of nature, appears reassuringly constant across the universe, according to a decades-long study of a distant pulsar. This research helps to answer a long-standing question in cosmology: Is the force of gravity the same everywhere and at all times? The answer, so far, appears to be yes.

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The ghost of a dying star — the Southern Owl Nebula

5 August 2015 Astronomy Now

This extraordinary bubble, glowing like the ghost of a star in the haunting darkness of space, may appear supernatural and mysterious, but it is a familiar astronomical object: a planetary nebula, the remnants of a dying star. This is the best view of the little-known object ESO 378-1 yet obtained and was captured by ESO’s Very Large Telescope in northern Chile.

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The long goodbye of a dying star

28 July 2015 Astronomy Now

A dying star’s final moments are captured in this image of planetary nebula NGC 6565 in Sagittarius from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star’s demise is still quite lengthy by our standards, lasting tens of thousands of years.

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Exiled stars explode far from home

5 June 2015 Astronomy Now

Hubble Space Telescope images confirm that three supernovae discovered several years ago exploded in the dark emptiness of intergalactic space — their nearest neighbours probably 300 light-years away — having been flung from their home galaxies millions or billions of years earlier.