Institute of Astronomy

Astronomy News

Lonely Galaxy 'Lost in Space'

11 June 2015 - 9:59am

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This magnificent spiral galaxy is at the edge of what astronomers call the Local Void. The Local Void is a huge volume of space that is at least 150 million light-years across that doesn't seen to contain anything much. There are no obvious galaxies. This void is simply part of the structure of the universe where matter grows clumpy over time so that galaxies form clusters and chains, which are separated by regions mostly devoid of galaxies. This results in sort of a "soap bubble" structure on large scales. The galaxy, as photographed by NASA's Hubble Space Telescope, is especially colorful where bright red patches of gas can be seen scattered through its spiral arms. Bright blue regions contain newly forming stars. Dark brown dust lanes snake across the galaxy's bright arms and center, giving it a mottled appearance.

Supernova prized by astronomers begins to fade from view

11 June 2015 - 9:57am

A stellar explosion known as SN 1987A is a favourite among astronomers as it is one of the closest to Earth, but it is now disappearing

First visit to Pluto could rewrite the solar system's story

11 June 2015 - 9:56am

Rivers of neon, geysers of nitrogen, an oddly giant moon: the New Horizons probe promises revealing spectacles – and insights into deep solar system history (full text available to subscribers)

Our exploration of the solar system is just getting started

11 June 2015 - 9:55am

Pluto might be the final stop on NASA's Grand Tour, but our visit marks the start of a new wave of exploration of the myriad worlds in our neighbourhood

Small particles dominate Saturn’s Phoebe ring to surprisingly large distances

11 June 2015 - 9:53am

Small particles dominate Saturn’s Phoebe ring to surprisingly large distances

Nature 522, 7555 (2015). doi:10.1038/nature14476

Authors: Douglas P. Hamilton, Michael F. Skrutskie, Anne J. Verbiscer & Frank J. Masci

Saturn’s faint outermost ring, discovered in 2009 (ref. 1), is probably formed by particles ejected from the distant moon Phoebe. The ring was detected between distances of 128 and 207 Saturn radii (RS = 60,330 kilometres) from the planet, with a full vertical extent of 40RS, making it well over ten times larger than Saturn’s hitherto largest known ring, the E ring. The total radial extent of the Phoebe ring could not, however, be determined at that time, nor could particle sizes be significantly constrained. Here we report infrared imaging of the entire ring, which extends from 100RS out to a surprisingly distant 270RS. We model the orbital dynamics of ring particles launched from Phoebe, and construct theoretical power-law profiles of the particle size distribution. We find that very steep profiles fit the data best, and that elevated grain temperatures, arising because of the radiative inefficiency of the smallest grains, probably contribute to the steepness. By converting our constraint on particle sizes into a form that is independent of the uncertain size distribution, we determine that particles with radii greater than ten centimetres, whose orbits do not decay appreciably inward over 4.5 billion years, contribute at most about ten per cent to the cross-sectional area of the ring’s dusty component.

Astronomy: Megaflare seen on star surface

11 June 2015 - 9:48am

Astronomy: Megaflare seen on star surface

Nature 522, 7555 (2015). doi:10.1038/522131d

Astronomers have spotted an enormous surge of light and magnetic energy on a nearby star.A team led by Wouter Vlemmings at Chalmers University of Technology near Gothenburg, Sweden, pointed the ALMA radio telescope in northern Chile at the red giant Mira A, a star

Ceres' spots seen in more detail

11 June 2015 - 9:38am

The US space agency releases a new, higher-resolution picture of the brightest spots on the dwarf planet Ceres.

Sharpest View Ever of Star Formation in the Distant Universe

9 June 2015 - 10:13am
ALMA’s Long Baseline Campaign has produced a spectacular image of a distant galaxy being gravitationally lensed. The image shows a magnified view of the galaxy’s star-forming regions, the likes of which have never been seen before at this level of detail in a galaxy so remote. The new observations are far sharper than those made using the NASA/ESA Hubble Space Telescope, and reveal star-forming clumps in the galaxy equivalent to giant versions of the Orion Nebula in the Milky Way.