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First-ever evidence of exoplanetary system found on 1917 photograph

13 April 2016 Astronomy Now

You can never predict what treasure might be hiding in your own basement. A researcher looking for a spectrum of a white dwarf known as van Maanen’s star found a 1917 image on an astronomical glass plate from the Carnegie Observatories’ collection that shows the first-ever evidence of a planetary system beyond our own Sun.

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Hubble reveals a cosmic trick of the eye

6 April 2016 Astronomy Now

While truly massive stars go out in a blaze of glory, intermediate-mass stars — those between roughly one and eight times the mass of the Sun — are somewhat quieter. Such stars eventually form cosmic objects known as planetary nebulae, so named because of their vague resemblance to planets when seen through early, low-resolution telescopes.

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Astronomers discover white dwarf with an oxygen atmosphere

3 April 2016 Astronomy Now

Researchers have discovered a white dwarf star with an atmosphere dominated by oxygen — a type of white dwarf that has been theorised to exist but not identified to date. The finding could challenge the textbook wisdom of single stellar evolution, and provide a critical link to some types of supernovae discovered over the past decade.

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Trigger for Milky Way’s youngest supernova identified

31 March 2016 Astronomy Now

Astronomers have used data from NASA’s Chandra X-ray Observatory and the VLA to determine the likely trigger for the most recent supernova in the Milky Way. They applied a new technique that could have implications for understanding other Type Ia supernovae, a class of stellar explosions that scientists use to determine the expansion rate of the universe.

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First discovery of a binary companion for a Type Ia supernova

23 March 2016 Astronomy Now

A team of astronomers has detected a flash of light from the companion star to supernova 2012cg that lies in the edge-on spiral NGC 4424, 50 million light-years away in the constellation Virgo. This is the first time that the impact of an exploding star on its neighbour has been witnessed.

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The icy blue wings of a bipolar planetary nebula

8 February 2016 Astronomy Now

Planetary nebulae such as Hen 2-437 form when an ageing low-mass star — such as the Sun — reaches the final stages of life. The star swells to become a red giant, before casting off its gaseous outer layers into space. Hen 2-437 is a bipolar nebula — the material ejected by the dying star has streamed out into space to create the two icy blue lobes pictured here.

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Astronomer solves mystery of ‘born again’ stars with Hubble

7 December 2015 Astronomy Now

University of Texas astronomer Natalie Gosnell has used the Hubble Space Telescope to better understand why some stars aren’t evolving as predicted. These so-called “blue stragglers” look hotter and bluer than they should for their advanced age. It’s almost as it they were somehow reinvigorated to look much younger than they really are.

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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.