Search Publications
Warm water vapour in the sooty outflow from a luminous carbon star
Ivison, R. J.; Blommaert, J. A. D. L.; Olofsson, G. +34 more
The detection of circumstellar water vapour around the ageing carbon star IRC +10216 challenged the current understanding of chemistry in old stars, because water was predicted to be almost absent in carbon-rich stars. Several explanations for the water were postulated, including the vaporization of icy bodies (comets or dwarf planets) in orbit ar…
A transiting giant planet with a temperature between 250K and 430K
Mazeh, T.; Aigrain, S.; Alonso, R. +58 more
Of the over 400 known exoplanets, there are about 70 planets that transit their central star, a situation that permits the derivation of their basic parameters and facilitates investigations of their atmospheres. Some short-period planets, including the first terrestrial exoplanet (CoRoT-7b), have been discovered using a space mission designed to …
Solar system: Recipe for making Saturn's rings
Charnoz, Sébastien; Crida, Aurélien
Simulations show that the still-mysterious origin of Saturn's vast, icy rings could be explained by the 'peeling' by Saturn's tides of the icy mantle of a large satellite migrating towards the planet. See Letter p.943
Planetary science: The birth of Saturn's baby moons
Burns, Joseph A.
Simulations show that Saturn's nearby moons, after forming on the outskirts of the planet's main rings, get pushed clear of them. This model reproduces the moons' orbital locations and remarkably low densities.
Broad line emission from iron K- and L-shell transitions in the active galaxy 1H0707-495
Larsson, J.; Young, A. J.; Brandt, W. N. +14 more
Since the 1995 discovery of the broad iron K-line emission from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K lines have been found in emission from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting neutron stars. The iron K line is prominent in the reflection spectrum created by the hard-X-ray…
An intermediate-mass black hole of over 500 solar masses in the galaxy ESO243-49
Godet, Olivier; Webb, Natalie A.; Barret, Didier +2 more
Ultraluminous X-ray sources are extragalactic objects located outside the nucleus of the host galaxy with bolometric luminosities exceeding 1039ergs-1. These extreme luminosities-if the emission is isotropic and below the theoretical (Eddington) limit, where the radiation pressure is balanced by the gravitational pressure-imp…
Liquid water on Enceladus from observations of ammonia and 40Ar in the plume
Young, D. T.; Ip, W. -H.; Lunine, J. I. +13 more
Jets of water ice from surface fractures near the south pole of Saturn's icy moon Enceladus produce a plume of gas and particles. The source of the jets may be a liquid water region under the ice shell-as suggested most recently by the discovery of salts in E-ring particles derived from the plume-or warm ice that is heated, causing dissociation of…
Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus
Kempf, S.; Postberg, F.; Srama, R. +5 more
Saturn's moon Enceladus emits plumes of water vapour and ice particles from fractures near its south pole, suggesting the possibility of a subsurface ocean. These plume particles are the dominant source of Saturn's E ring. A previous in situ analysis of these particles concluded that the minor organic or siliceous components, identified in many ic…
A massive hypergiant star as the progenitor of the supernova SN 2005gl
Gal-Yam, A.; Leonard, D. C.
Our understanding of the evolution of massive stars before their final explosions as supernovae is incomplete, from both an observational and a theoretical standpoint. A key missing piece in the supernova puzzle is the difficulty of identifying and studying progenitor stars. In only a single case-that of supernova SN 1987A in the Large Magellanic …
The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge
Dalessandro, E.; Ransom, S. M.; Valenti, E. +9 more
Globular star clusters are compact and massive stellar systems old enough to have witnessed the entire history of our Galaxy, the Milky Way. Although recent results suggest that their formation may have been more complex than previously thought, they still are the best approximation to a stellar population formed over a relatively short timescale …