Institute of Astronomy

Feed aggregator

Hawking backs 'starship' project

Astronomy News - 13 April 2016 - 9:12am

Professor Stephen Hawking backs a project to send spaceships to another solar system within a generation

NASA recovers prized Kepler space telescope after emergency

Astronomy News - 12 April 2016 - 9:20am

The flagship spacecraft in the search for exoplanets has switched on its emergency mode just prior to a new phase of operations

Planets stripped bare by host stars

Astronomy News - 12 April 2016 - 9:19am

Astronomers have defined a class of planet that have had their atmospheres stripped away by their host stars.

Mars moons may have formed after collision with Pluto-like world

Astronomy News - 11 April 2016 - 9:10am

Many think the tiny Phobos and Deimos are merely captured asteroids, but a new model suggests they had a more violent origin

NASA’s Next Great Space Telescope

Astronomy News - 11 April 2016 - 9:09am

Assembly of the next great space observatory, the James Webb Space Telescope (JWST), is now underway at NASA’s Goddard Space Flight Center.

Lab cooks up sugars from 'comet ice'

Astronomy News - 11 April 2016 - 9:08am

Experiments show how ribose - an important sugar for life - can form when a simple icy mixture is hit by UV light.

Planet Nine's profile fleshed out

Astronomy News - 11 April 2016 - 9:08am

Astrophysicists outline what Planet Nine might be like - if indeed it exists.

The colour-changing comet

Astronomy News - 8 April 2016 - 10:04am

Rosetta's comet has been seen changing colour and brightness in front of the ESA orbiter's eyes, as the Sun's heat strips away the older surface to reveal fresher material.

Behemoth black hole found in an unlikely place [heic1607]

Astronomy News - 7 April 2016 - 9:36am

Astronomers have uncovered one of the biggest supermassive black holes, with the mass of 17 billion Suns, in an unlikely place: the centre of a galaxy that lies in a quiet backwater of the Universe. The observations, made with the NASA/ESA Hubble Space Telescope and the Gemini Telescope in Hawaii, indicate that these monster objects may be more common than once thought. The results of this study are released in the journal Nature.

Behemoth Black Hole Found in an Unlikely Place

Astronomy News - 7 April 2016 - 9:35am

Get larger image formats

Imagine driving through a small town containing modest-sized buildings and seeing a 100-story skyscraper. Astronomers found the equivalent monstrosity in space: a near-record supermassive black hole that weighs 17 billion suns and lives in a cosmic backwater community of a few galaxies. Until now, extremely massive black holes have been found at the cores of very large galaxies in regions of the universe packed with other large galaxies. This is not just coincidence. Like a cosmic Pac-Man, a monster black hole gobbles smaller black holes when two galaxies collide. This game of bumper cars is common in large galaxy clusters. In fact, the current black hole record holder tips the scale at 21 billion suns and resides in the crowded Coma galaxy cluster, located 330 million light-years away.

Controversial dark-matter claim faces ultimate test

Astronomy News - 7 April 2016 - 9:34am

Controversial dark-matter claim faces ultimate test

Nature 532, 7597 (2016).

Author: Davide Castelvecchi

Multiple teams finally have the material they need to repeat enigmatic experiment.

Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60Fe

Astronomy News - 7 April 2016 - 9:34am

Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60Fe

Nature 532, 7597 (2016). doi:10.1038/nature17196

Authors: A. Wallner, J. Feige, N. Kinoshita, M. Paul, L. K. Fifield, R. Golser, M. Honda, U. Linnemann, H. Matsuzaki, S. Merchel, G. Rugel, S. G. Tims, P. Steier, T. Yamagata & S. R. Winkler

The rate of supernovae in our local Galactic neighbourhood within a distance of about 100 parsecs from Earth is estimated to be one every 2–4 million years, based on the total rate in the Milky Way (2.0 ± 0.7 per century). Recent massive-star and supernova activity in Earth’s vicinity may be traced by radionuclides with half-lives of up to 100 million years, if trapped in interstellar dust grains that penetrate the Solar System. One such radionuclide is 60Fe (with a half-life of 2.6 million years), which is ejected in supernova explosions and winds from massive stars. Here we report that the 60Fe signal observed previously in deep-sea crusts is global, extended in time and of interstellar origin from multiple events. We analysed deep-sea archives from all major oceans for 60Fe deposition via the accretion of interstellar dust particles. Our results reveal 60Fe interstellar influxes onto Earth at 1.5–3.2 million years ago and at 6.5–8.7 million years ago. The signal measured implies that a few per cent of fresh 60Fe was captured in dust and deposited on Earth. Our findings indicate multiple supernova and massive-star events during the last ten million years at distances of up to 100 parsecs.

The locations of recent supernovae near the Sun from modelling 60Fe transport

Astronomy News - 7 April 2016 - 9:34am

The locations of recent supernovae near the Sun from modelling 60Fe transport

Nature 532, 7597 (2016). doi:10.1038/nature17424

Authors: D. Breitschwerdt, J. Feige, M. M. Schulreich, M. A. de. Avillez, C. Dettbarn & B. Fuchs

The signature of 60Fe in deep-sea crusts indicates that one or more supernovae exploded in the solar neighbourhood about 2.2 million years ago. Recent isotopic analysis is consistent with a core-collapse or electron-capture supernova that occurred 60 to 130 parsecs from the Sun. Moreover, peculiarities in the cosmic ray spectrum point to a nearby supernova about two million years ago. The Local Bubble of hot, diffuse plasma, in which the Solar System is embedded, originated from 14 to 20 supernovae within a moving group, whose surviving members are now in the Scorpius–Centaurus stellar association. Here we report calculations of the most probable trajectories and masses of the supernova progenitors, and hence their explosion times and sites. The 60Fe signal arises from two supernovae at distances between 90 and 100 parsecs. The closest occurred 2.3 million years ago at present-day galactic coordinates l = 327°, b = 11°, and the second-closest exploded about 1.5 million years ago at l = 343°, b = 25°, with masses of 9.2 and 8.8 times the solar mass, respectively. The remaining supernovae, which formed the Local Bubble, contribute to a smaller extent because they happened at larger distances and longer ago (60Fe has a half-life of 2.6 million years). There are uncertainties relating to the nucleosynthesis yields and the loss of 60Fe during transport, but they do not influence the relative distribution of 60Fe in the crust layers, and therefore our model reproduces the measured relative abundances very well.

Stellar astrophysics: Supernovae in the neighbourhood

Astronomy News - 7 April 2016 - 9:33am

Stellar astrophysics: Supernovae in the neighbourhood

Nature 532, 7597 (2016). doi:10.1038/532040a

Authors: Adrian L. Melott

Detailed measurements of radioisotopes in deep-sea deposits, plus modelling of how they reached Earth, indicate that many supernovae have occurred near enough to have potentially influenced evolution. See Letters p.69 & p.73

Astrophysics: Black-hole crackle-and-pop

Astronomy News - 7 April 2016 - 9:32am

Astrophysics: Black-hole crackle-and-pop

Nature 532, 7597 (2016). doi:10.1038/532009f

Gravitational 'noise' could be easier to detect than previously thought.Gravitational waves were first observed in 2015 by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors (pictured). This demonstrated the existence of binary black holes and suggested that these are more abundant than

Astronomy: White dwarf's weird atmosphere

Astronomy News - 7 April 2016 - 9:32am

Astronomy: White dwarf's weird atmosphere

Nature 532, 7597 (2016). doi:10.1038/532008d

Astronomers have discovered a white dwarf star that has an atmosphere made almost entirely of oxygen — the first of its kind to be discovered.White dwarfs are the dense cores that get left behind when a relatively small star's nuclear fuel runs out and

Exploding stars left mark on Earth

Astronomy News - 7 April 2016 - 9:27am

Two studies confirm that multiple supernovae have showered the Earth with radiation within the last few million years.

Pluto may have tipped over when Charon tugged at its heart

Astronomy News - 5 April 2016 - 8:23am

The iconic heart-shaped feature on Pluto is so dense that it could have led to the entire dwarf planet swivelling over time

Planet Nine might be an exoplanet stolen by the sun

Astronomy News - 5 April 2016 - 8:21am

The hypothetical ninth planet at the fringes of our solar system might have been captured from a star passing by long ago

SETI looks at red dwarf stars in its search for ancient aliens

Astronomy News - 5 April 2016 - 8:18am

The extraterrestrial-hunting SETI Institute is aiming its array of radio telescopes at 20,000 small, cold stars unlike our own to see if anyone is home