Institute of Astronomy

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Mystery Mars plume baffles scientists

Astronomy News - 16 February 2015 - 7:03pm

Plumes seen reaching high above the surface of Mars are causing a stir among scientists studying the atmosphere on the Red Planet.

Mystery cloud-like blobs over Mars baffle astronomers

Astronomy News - 16 February 2015 - 6:51pm
In 2012, amateur astronomers spotted at least one unidentified object rising into the Martian sky. Could auroras, volcanoes or aliens be to blame?

Mystery Mars haze baffles scientists

Astronomy News - 16 February 2015 - 5:08pm
Scientists struggle to explain a vast haze that was spotted high above the Martian surface in 2012 by amateur astronomers.

Contacting aliens - war of the worlds or war over cash?

Astronomy News - 15 February 2015 - 7:46pm

Should we actively direct signals to aliens? Some say yes, while others worry about dire consequences for humanity and their research funding

Camera seeks dark energy clues

Astronomy News - 14 February 2015 - 4:40pm

California scientists have given details of a telescope camera they are assembling to study "dark energy".

Orion has a giant dust hula hoop around its waist

Astronomy News - 13 February 2015 - 9:44pm
Astronomers have uncovered a giant dust ring after mapping the 3D distribution of dust in the well-studied celestial region of Orion

Interstellar's true black hole too confusing

Astronomy News - 13 February 2015 - 12:31pm

The blockbuster film was the first to use real physics to portray a black hole, but they toned down the science for artistic effect

Scientists urged to contact aliens

Astronomy News - 12 February 2015 - 8:51pm

Scientists at a US conference in say the time has come to try actively to make contact with intelligent life on other worlds.

RAS meetings this Friday 13 Feb: - Ordinary Meeting has talks on Herschel-SPIRE...

Astronomy News - 11 February 2015 - 8:35pm
RAS meetings this Friday 13 Feb:

- Ordinary Meeting has talks on Herschel-SPIRE, meteorites, black holes and Robert Hooke

- 'Surveying the transient Universe: from electromagnetic to gravitational waves'

- 'Meeting the challenges in Upper Atmospheric Science'

Cosmology: The oldest cosmic light

Astronomy News - 11 February 2015 - 8:19pm

Cosmology: The oldest cosmic light

Nature 518, 7538 (2015). doi:10.1038/518170a

Authors: David Spergel & Brian Keating

The cosmic microwave background is a faint glow of light left over from the Big Bang. It fills the entire sky and records the Universe's early history. Two independent experts outline what we know about this ancient light, both theoretically and observationally.

Star formation: Sibling rivalry begins at birth

Astronomy News - 11 February 2015 - 8:19pm

Star formation: Sibling rivalry begins at birth

Nature 518, 7538 (2015). doi:10.1038/518173a

Authors: Kaitlin M. Kratter

High-resolution astronomical observations of a nearby molecular gas cloud have revealed a quadruplet of stars in the act of formation. The system is arguably the youngest multiple star system detected so far. See Letter p.213

The formation of a quadruple star system with wide separation

Astronomy News - 11 February 2015 - 8:19pm

The formation of a quadruple star system with wide separation

Nature 518, 7538 (2015). doi:10.1038/nature14166

Authors: Jaime E. Pineda, Stella S. R. Offner, Richard J. Parker, Héctor G. Arce, Alyssa A. Goodman, Paola Caselli, Gary A. Fuller, Tyler L. Bourke & Stuartt A. Corder

The initial multiplicity of stellar systems is highly uncertain. A number of mechanisms have been proposed to explain the origin of binary and multiple star systems, including core fragmentation, disk fragmentation and stellar capture. Observations show that protostellar and pre-main-sequence multiplicity is higher than the multiplicity found in field stars, which suggests that dynamical interactions occur early, splitting up multiple systems and modifying the initial stellar separations. Without direct, high-resolution observations of forming systems, however, it is difficult to determine the true initial multiplicity and the dominant binary formation mechanism. Here we report observations of a wide-separation (greater than 1,000 astronomical units) quadruple system composed of a young protostar and three gravitationally bound dense gas condensations. These condensations are the result of fragmentation of dense gas filaments, and each condensation is expected to form a star on a timescale of 40,000 years. We determine that the closest pair will form a bound binary, while the quadruple stellar system itself is bound but unstable on timescales of 500,000 years (comparable to the lifetime of the embedded protostellar phase). These observations suggest that filament fragmentation on length scales of about 5,000 astronomical units offers a viable pathway to the formation of multiple systems.

Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years

Astronomy News - 11 February 2015 - 8:19pm

Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years

Nature 518, 7538 (2015). doi:10.1038/nature14159

Authors: Rita Schulz, Martin Hilchenbach, Yves Langevin, Jochen Kissel, Johan Silen, Christelle Briois, Cecile Engrand, Klaus Hornung, Donia Baklouti, Anaïs Bardyn, Hervé Cottin, Henning Fischer, Nicolas Fray, Marie Godard, Harry Lehto, Léna Le Roy, Sihane Merouane, François-Régis Orthous-Daunay, John Paquette, Jouni Rynö, Sandra Siljeström, Oliver Stenzel, Laurent Thirkell, Kurt Varmuza & Boris Zaprudin

Comets are composed of dust and frozen gases. The ices are mixed with the refractory material either as an icy conglomerate, or as an aggregate of pre-solar grains (grains that existed prior to the formation of the Solar System), mantled by an ice layer. The presence of water-ice grains in periodic comets is now well established. Modelling of infrared spectra obtained about ten kilometres from the nucleus of comet Hartley 2 suggests that larger dust particles are being physically decoupled from fine-grained water-ice particles that may be aggregates, which supports the icy-conglomerate model. It is known that comets build up crusts of dust that are subsequently shed as they approach perihelion. Micrometre-sized interplanetary dust particles collected in the Earth’s stratosphere and certain micrometeorites are assumed to be of cometary origin. Here we report that grains collected from the Jupiter-family comet 67P/Churyumov-Gerasimenko come from a dusty crust that quenches the material outflow activity at the comet surface. The larger grains (exceeding 50 micrometres across) are fluffy (with porosity over 50 per cent), and many shattered when collected on the target plate, suggesting that they are agglomerates of entities in the size range of interplanetary dust particles. Their surfaces are generally rich in sodium, which explains the high sodium abundance in cometary meteoroids. The particles collected to date therefore probably represent parent material of interplanetary dust particles. This argues against comet dust being composed of a silicate core mantled by organic refractory material and then by a mixture of water-dominated ices. At its previous recurrence (orbital period 6.5 years), the comet’s dust production doubled when it was between 2.7 and 2.5 astronomical units from the Sun, indicating that this was when the nucleus shed its mantle. Once the mantle is shed, unprocessed material starts to supply the developing coma, radically changing its dust component, which then also contains icy grains, as detected during encounters with other comets closer to the Sun.

Hovering happy face smiles down on us from space

Astronomy News - 10 February 2015 - 3:31pm

It's not the Man in the Moon. A smiley face seen in deep space is the work of a cosmic quirk

Doomed stars found at nebula's heart

Astronomy News - 9 February 2015 - 8:44pm

At the centre of a mysterious nebula, astronomers discover two stars locked in such a tight orbit that they will eventually merge and explode.

Stellar Partnership Doomed to End in Catastrophe

Astronomy News - 9 February 2015 - 5:14pm
Astronomers using ESO facilities in combination with telescopes in the Canary Islands have identified two surprisingly massive stars at the heart of the planetary nebula Henize 2-428. As they orbit each other the two stars are expected to slowly get closer and closer, and when they merge, about 700 million years from now, they will contain enough material to ignite a vast supernova explosion. The results will appear online in the journal Nature on 9 February 2015.

VIDEO: Nasa reveals far side of the Moon

Astronomy News - 9 February 2015 - 1:54pm

Using nearly five-years worth of mapping data from the Lunar Reconnaissance Orbiter, NASA has to provided a view of the moon from the side the cannot be seen from earth.

VIDEO: New satellite warns of solar storms

Astronomy News - 7 February 2015 - 10:17am

A new deep space satellite will give quicker and more accurate notice about approaching solar storms.

Hubble Captures Rare Triple-Moon Conjunction

Astronomy News - 6 February 2015 - 9:03pm
NASA's Hubble Space Telescope has captured the rare occurrence of three of Jupiter's largest moons racing across the banded face of the gas-giant planet: Europa, Callisto, and Io.

Pluto's evaporating ice leaves it with a blank face

Astronomy News - 6 February 2015 - 8:06pm

Astronomers hoped Pluto's craters would hold a record of impacts from its neighbours, which are too small to see – a new study dashes those hopes