Institute of Astronomy

Feed aggregator

Cassini crashes into Saturn — but could still deliver big discoveries

Astronomy News - 21 September 2017 - 9:55am

Cassini crashes into Saturn — but could still deliver big discoveries

Nature 549, 7672 (2017).

Author: Alexandra Witze

Data from spacecraft could help determine the age of Saturn's rings and the persistence of its magnetic field.

A binary main-belt comet

Astronomy News - 21 September 2017 - 9:49am

A binary main-belt comet

Nature 549, 7672 (2017). doi:10.1038/nature23892

Authors: Jessica Agarwal, David Jewitt, Max Mutchler, Harold Weaver & Stephen Larson

Asteroids are primitive Solar System bodies that evolve both collisionally and through disruptions arising from rapid rotation. These processes can lead to the formation of binary asteroids and to the release of dust, both directly and, in some cases, through uncovering frozen volatiles. In a subset of the asteroids called main-belt comets, the sublimation of excavated volatiles causes transient comet-like activity. Torques exerted by sublimation measurably influence the spin rates of active comets and might lead to the splitting of bilobate comet nuclei. The kilometre-sized main-belt asteroid 288P (300163) showed activity for several months around its perihelion 2011 (ref. 11), suspected to be sustained by the sublimation of water ice and supported by rapid rotation, while at least one component rotates slowly with a period of 16 hours (ref. 14). The object 288P is part of a young family of at least 11 asteroids that formed from a precursor about 10 kilometres in diameter during a shattering collision 7.5 million years ago. Here we report that 288P is a binary main-belt comet. It is different from the known asteroid binaries in its combination of wide separation, near-equal component size, high eccentricity and comet-like activity. The observations also provide strong support for sublimation as the driver of activity in 288P and show that sublimation torques may play an important part in binary orbit evolution.

Gravity may be created by strange flashes in the quantum realm

Astronomy News - 21 September 2017 - 9:48am

A model of how wave forms of quantum systems collapse reveals a way they could create gravitational fields, and perhaps even reconcile two pillars of physics

Our closest star system may be home to a stolen star and planet

Astronomy News - 21 September 2017 - 9:47am

Proxima b, the nearest exoplanet to Earth, may have been captured along with its star instead of born in the dangerous three-star system where it now lives

Infamous three-body problem has over a thousand new solutions

Astronomy News - 21 September 2017 - 9:47am

A long-standing maths puzzle has 1223 new solutions, more than doubling the number of possible paths three objects can take as they orbit one another

Ageing Star Blows Off Smoky Bubble

Astronomy News - 21 September 2017 - 9:44am
Astronomers have used ALMA to capture a strikingly beautiful view of a delicate bubble of expelled material around the exotic red star U Antliae. These observations will help astronomers to better understand how stars evolve during the later stages of their life-cycles.

Herschel's chronicles of galaxy evolution

Astronomy News - 21 September 2017 - 9:42am

Delving deep into the history of our cosmos, the Herschel Space Observatory scrutinised hundreds of thousands of star-forming galaxies, peering back in time to when the Universe was less than one billion years old. These observations probed the peak epoch of stellar production, about ten billion years ago, when galaxies were forming stars roughly ten times faster than their present counterparts.

Hubble discovers a unique type of object in the Solar System [heic1715]

Astronomy News - 21 September 2017 - 9:41am

With the help of the NASA/ESA Hubble Space Telescope, a German-led group of astronomers have observed the intriguing characteristics of an unusual type of object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. This is the first known binary asteroid also classified as a comet. The research is presented in a paper published in the journal Nature this week.

The cosmic water trail uncovered by Herschel

Astronomy News - 20 September 2017 - 8:58am

During almost four years of observing the cosmos, the Herschel Space Observatory traced out the presence of water. With its unprecedented sensitivity and spectral resolution at key wavelengths, Herschel revealed this crucial molecule in star-forming molecular clouds, detected it for the first time in the seeds of future stars and planets, and identified the delivery of water from interplanetary debris to planets in our Solar System.

Mysterious flashing star seems destined for an explosive end

Astronomy News - 19 September 2017 - 9:53am

A detective story that began in the 1950s when a star seemed to go supernova but survived ended this month when someone figured out what was going on

How Herschel unlocked the secrets of star formation

Astronomy News - 19 September 2017 - 9:42am

Surveying the sky for almost four years to observe the glow of cold cosmic dust embedded in interstellar clouds of gas, the Herschel Space Observatory has provided astronomers with an unprecedented glimpse into the stellar cradles of our Galaxy. As a result, giant strides have been taken in our understanding of the physical processes that lead to the birth of stars and their planetary systems.

Brown dwarfs have strong magnetic fields just like real stars

Astronomy News - 18 September 2017 - 9:26am

Failed stars called brown dwarfs straddle the line between big planets and small stars. An observation of a magnetic field puts another tick in the star column

NASA’s Cassini Spacecraft Ends Its Historic Exploration of Saturn

Astronomy News - 18 September 2017 - 9:25am
A thrilling epoch in the exploration of our solar system came to a close today, as NASA's Cassini spacecraft made a fateful plunge into the atmosphere of Saturn, ending its 13-year tour of the ringed planet.

Cassini concludes pioneering mission at Saturn

Astronomy News - 18 September 2017 - 9:25am

The international Cassini mission has concluded its remarkable exploration of the Saturnian system in spectacular style, by plunging into the gas planet's atmosphere.

Venus' mysterious night side revealed

Astronomy News - 15 September 2017 - 9:26am

Scientists have used ESA's Venus Express to characterise the wind and upper cloud patterns on the night side of Venus for the first time–with surprising results.

Hubble observes pitch black planet [heic1714]

Astronomy News - 15 September 2017 - 9:25am

Astronomers have discovered that the well-studied exoplanet WASP-12b reflects almost no light, making it appear essentially pitch black. This discovery sheds new light on the atmospheric composition of the planet and also refutes previous hypotheses about WASP-12b's atmosphere. The results are also in stark contrast to observations of another similarly sized exoplanet.

Why scientists are so excited about Saturn's icy moon Enceladus

Astronomy News - 15 September 2017 - 9:25am

Scientists explain how they discovered a water ocean beneath the ice shell of Saturn's moon Enceladus.

Cassini: Saturn 'death dive' spacecraft in numbers

Astronomy News - 15 September 2017 - 9:24am

Cassini's come to a fiery end on Saturn, but here's what it achieved over the last two decades.

Cassini: Saturn probe heads towards destruction

Astronomy News - 15 September 2017 - 9:24am

The end is near for US-led space mission as it flies towards a fiery impact with the ringed planet.

Optical physics: A laser model for cosmology

Astronomy News - 14 September 2017 - 10:04am

Optical physics: A laser model for cosmology

Nature 549, 7671 (2017). doi:10.1038/549163a

Authors: Stefan Rotter

Experiments reveal that the laws governing the immediate aftermath of the Big Bang also apply to the behaviour of coupled lasers. The findings could be used to solve complex computational problems.