Institute of Astronomy

Feed aggregator

Stephen Hawking’s Reith Lecture: Annotated transcript

Astronomy News - 27 January 2016 - 9:07am

A transcript of Stephen Hawking's first Reith Lecture, annotated by BBC science editor David Shukman

Hubble successor maintains course

Astronomy News - 26 January 2016 - 9:16am

James Webb, the space telescope that will take over from Hubble, is reaching some key milestones in its preparation for launch in 2018.

Dazzling diamonds [heic1601]

Astronomy News - 25 January 2016 - 9:32am

Single stars are often overlooked in favour of their larger cosmic cousins – but when they join forces, they create truly breathtaking scenes to rival even the most glowing of nebulae or swirling of galaxies. This NASA/ESA Hubble Space Telescope image features the star cluster Trumpler 14. One of the largest gatherings of hot, massive and bright stars in the Milky Way, this cluster houses some of the most luminous stars in our entire galaxy.

LISA Pathfinder arrives at its worksite

Astronomy News - 25 January 2016 - 9:32am

After a six-week journey, LISA Pathfinder arrived at its destination today, an orbit around a point of balance in space where it will soon start testing technologies crucial for exploring the gravitational Universe.

Galaxy-mapping Gaia space telescope gets an eye test from Pluto

Astronomy News - 25 January 2016 - 9:26am

The European Space Agency craft designed to map a billion stars in the Milky Way has also been keeping an eye out for everyone's favourite dwarf planet

Mystery supernova could be fast-spinning magnetic star

Astronomy News - 22 January 2016 - 9:07am

The brightest ever supernova was confirmed last week, but no one could explain it. Now a culprit has been found: a magnetar driven by an extremely massive star

Hubble Unveils a Tapestry of Dazzling Diamond-Like Stars

Astronomy News - 22 January 2016 - 9:06am

Get larger image formats

Some of the Milky Way's "celebrity stars" opulent, attention-getting, and short-lived can be found in this Hubble Space Telescope image of the glittering star cluster called Trumpler 14. It is located 8,000 light-years away in the Carina Nebula, a huge star-formation region in our galaxy. Because the cluster is only 500,000 years old, it has one of the highest concentrations of massive, luminous stars in the entire Milky Way. Like some Hollywood celebrities, the stars will go out in a flash. Within just a few million years they will burn out and explode as supernovae. But the story's not over. The blast waves will trigger the formation of a new generation of stars inside the nebula in an ongoing cycle of star birth and death.

Come in #PlanetNine

Astronomy News - 22 January 2016 - 9:03am

US astronomers claim to have strong evidence that there is a ninth planet in our Solar System. We asked you to send us your suggested names for this new arrival.

VIDEO: Does the ninth planet really exist?

Astronomy News - 22 January 2016 - 9:02am

Why do astronomers in the US think there they have discovered a ninth planet in the solar system?

A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars

Astronomy News - 21 January 2016 - 10:07am

A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars

Nature 529, 7586 (2016). doi:10.1038/nature16171

Authors: Dennis Stello, Matteo Cantiello, Jim Fuller, Daniel Huber, Rafael A. García, Timothy R. Bedding, Lars Bildsten & Victor Silva Aguirre

Magnetic fields play a part in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have deep convective envelopes, although 10 per cent exhibit strong surface fields that are presumed to be residuals from the star formation process. These stars do have convective cores that might produce internal magnetic fields, and these fields might survive into later stages of stellar evolution, but information has been limited by our inability to measure the fields below the stellar surface. Here we report the strength of dipolar oscillation modes for a sample of 3,600 red giant stars. About 20 per cent of our sample show mode suppression, by strong magnetic fields in the cores, but this fraction is a strong function of mass. Strong core fields occur only in red giants heavier than 1.1 solar masses, and the occurrence rate is at least 50 per cent for intermediate-mass stars (1.6–2.0 solar masses), indicating that powerful dynamos were very common in the previously convective cores of these stars.

Exposed water ice on the nucleus of comet 67P/Churyumov–Gerasimenko

Astronomy News - 21 January 2016 - 10:07am

Exposed water ice on the nucleus of comet 67P/Churyumov–Gerasimenko

Nature 529, 7586 (2016). doi:10.1038/nature16190

Authors: G. Filacchione, M. C. De Sanctis, F. Capaccioni, A. Raponi, F. Tosi, M. Ciarniello, P. Cerroni, G. Piccioni, M. T. Capria, E. Palomba, G. Bellucci, S. Erard, D. Bockelee-Morvan, C. Leyrat, G. Arnold, M. A. Barucci, M. Fulchignoni, B. Schmitt, E. Quirico, R. Jaumann, K. Stephan, A. Longobardo, V. Mennella, A. Migliorini, E. Ammannito, J. Benkhoff, J. P. Bibring, A. Blanco, M. I. Blecka, R. Carlson, U. Carsenty, L. Colangeli, M. Combes, M. Combi, J. Crovisier, P. Drossart, T. Encrenaz, C. Federico, U. Fink, S. Fonti, W. H. Ip, P. Irwin, E. Kuehrt, Y. Langevin, G. Magni, T. McCord, L. Moroz, S. Mottola, V. Orofino, U. Schade, F. Taylor, D. Tiphene, G. P. Tozzi, P. Beck, N. Biver, L. Bonal, J-Ph. Combe, D. Despan, E. Flamini, M. Formisano, S. Fornasier, A. Frigeri, D. Grassi, M. S. Gudipati, D. Kappel, F. Mancarella, K. Markus, F. Merlin, R. Orosei, G. Rinaldi, M. Cartacci, A. Cicchetti, S. Giuppi, Y. Hello, F. Henry, S. Jacquinod, J. M. Reess, R. Noschese, R. Politi & G. Peter

Although water vapour is the main species observed in the coma of comet 67P/Churyumov–Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov–Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov–Gerasimenko is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet’s formation.

Evidence grows for giant planet on fringes of Solar System

Astronomy News - 21 January 2016 - 10:05am

Evidence grows for giant planet on fringes of Solar System

Nature 529, 7586 (2016).

Author: Alexandra Witze

Gravitational signature hints at massive object that orbits the Sun every 20,000 years.

Astronomy: Brightest-ever supernova

Astronomy News - 21 January 2016 - 10:04am

Astronomy: Brightest-ever supernova

Nature 529, 7586 (2016). doi:10.1038/529259d

A supernova has been spotted that is twice as luminous as the previous record holder — at its peak it blazed brighter than 570 billion Suns.Subo Dong at Peking University in Beijing and his colleagues spotted the exploding star, called ASASSN-15lh, in June last

Five planets align in dawn sky

Astronomy News - 21 January 2016 - 9:46am

Five planets will align across the dawn sky on Wednesday in a rare treat for skywatchers.

Case made for 'ninth planet'

Astronomy News - 21 January 2016 - 9:46am

American astronomers say they have strong evidence that there is a ninth planet in our Solar System orbiting far beyond even the dwarf world Pluto.

VIDEO: 'I'm sceptical about ninth planet'

Astronomy News - 21 January 2016 - 9:44am

Nasa's chief scientist says she is a bit "sceptical" about the existence of a ninth planet in our Solar System.

Black hole sun could support bizarre life on orbiting planets

Astronomy News - 19 January 2016 - 9:51am

A reversal of thermodynamics could allow life to exist on planets orbiting a black hole, as seen in the film Interstellar

Comets can’t explain weird ‘alien megastructure’ star after all

Astronomy News - 18 January 2016 - 9:29am

A star called KIC 8462852, or Tabby's star, has been behaving oddly since 1890, not just recently as had been thought – and astronomers have no idea why

The Turbulent Birth of a Quasar

Astronomy News - 15 January 2016 - 4:26pm
The most luminous galaxy known in the Universe — the quasar W2246-0526, seen when the Universe was less than 10% of its current age — is so turbulent that it is in the process of ejecting its entire supply of star-forming gas, according to new observations with the Atacama Large Millimeter/submillimeter Array (ALMA).

We’ve found the brightest ever supernova but can’t explain it

Astronomy News - 15 January 2016 - 9:39am

Astronomers are now sure the incredibly violent stellar explosion spotted last June is the brightest ever seen. But they remain baffled about its source