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Discovery of binary-binary calls solar system formation into question

20 October 2016 Astronomy Now

University of Florida astronomers have discovered the first “binary-binary” — two massive companions around one star in a close binary system, one so-called giant planet and one brown dwarf, or “failed star.” For such large companion objects to be stable so close together defies our current popular theories on how solar systems form.

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Discovering the X-ray treasures in Chandra’s archives

16 October 2016 Astronomy Now

Each year, NASA’s Chandra X-ray Observatory helps celebrate American Archive Month by releasing a collection of images using X-ray data. Each of these six new images — representing just a small fraction of the treasures that reside in Chandra’s unique archive — also includes data from telescopes covering other parts of the electromagnetic spectrum, such as visible and infrared light.

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Astronomers use cosmic voids to study the universe

12 August 2016 Astronomy Now

Researchers who are looking for new ways to probe the nature of gravity and dark energy in the universe have adopted a new strategy: looking at what’s not there. An international team of astronomers were able to achieve four times better precision in measurements of how the universe’s visible matter is clustered together by studying the empty spaces in between.

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Ancient eye in the sky reveals galaxies

26 July 2016 Astronomy Now

A gravitational lens system has been discovered by undergraduate students examining images from the 8.2-metre Subaru Telescope’s Hyper Suprime-Cam. Dubbed the “Eye of Horus” due to the system’s uncanny resemblance to the sacred eye of the ancient Egyptian goddess, it is formed by a galaxy 7 billion light-years from the Earth bending the light from two more galaxies directly behind it.

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‘Frankenstein’ galaxy UGC 1382 surprises astronomers

13 July 2016 Astronomy Now

About 250 million light-years away, there’s a neighbourhood of our universe that astronomers had considered quiet and unremarkable. But now, scientists have uncovered an enormous, bizarre galaxy possibly formed from the parts of other galaxies. Some 718,000 light-years across, UGC 1382 is more than seven times wider than the Milky Way.

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Minor galaxy mergers are major drivers of star formation

28 June 2016 Astronomy Now

Around half of the star formation in the local universe arises from minor mergers between galaxies, according to data from the Sloan Digital Sky Survey. Disruptions to the shapes of spiral galaxies, caused by interactions with their smallest neighbours, points to increased star formation. Evidence suggests that minor galactic mergers are therefore important drivers of galaxy evolution.

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A young mammoth cluster of galaxies sighted in the early universe

25 May 2016 Astronomy Now

Astronomers have uncovered evidence for a vast collection of young galaxies 12 billion light years away. The newly discovered “proto-cluster” of galaxies, observed when the universe was only 1.7 billion years old (12 percent of its present age), is one of the most massive structures known at that distance.

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Astronomers detect double ‘peanut shell’ galaxies

8 May 2016 Astronomy Now

Astronomers at Swinburne University of Technology, Melbourne, have discovered an unusually shaped structure in two nearby disc galaxies. The Swinburne team recently developed new imaging software, making it possible to observe the double “peanut shell shape” formed by the distribution of stars bulging from the centres of these galaxies.

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Speeding binary star discovered approaching galactic escape velocity

14 April 2016 Astronomy Now

There are about two dozen so-called hypervelocity stars known to be escaping our Milky Way galaxy, but PB 3877 is the first wide binary star found to travel at such a high speed. The results of a new study challenge the commonly accepted scenario that hypervelocity stars are accelerated by the supermassive black hole at the galactic centre.

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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.