Institute of Astronomy

Astronomy News

Dawn probe set for Ceres arrival

6 March 2015 - 10:04am

Nasa is waiting for confirmation that its Dawn probe has gone into orbit around Ceres, the largest object in the asteroid belt between Mars and Jupiter.

The double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2-428

5 March 2015 - 9:00am

The double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2-428

Nature 519, 7541 (2015). doi:10.1038/nature14124

Authors: M. Santander-García, P. Rodríguez-Gil, R. L. M. Corradi, D. Jones, B. Miszalski, H. M. J. Boffin, M. M. Rubio-Díez & M. M. Kotze

The planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the Sun (). The origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. In close binary systems, the orbital separation is short enough for the primary star to overfill its Roche lobe as the star expands during the asymptotic giant branch phase. The excess gas eventually forms a common envelope surrounding both stars. Drag forces then result in the envelope being ejected into a bipolar planetary nebula whose equator is coincident with the orbital plane of the system. Systems in which both stars have ejected their envelopes and are evolving towards the white dwarf stage are said to be double degenerate. Here we report that Henize 2-428 has a double-degenerate core with a combined mass of ∼1.76, which is above the Chandrasekhar limit (the maximum mass of a stable white dwarf) of 1.4. This, together with its short orbital period (4.2 hours), suggests that the system should merge in 700 million years, triggering a type Ia supernova event. This supports the hypothesis of the double-degenerate, super-Chandrasekhar evolutionary pathway for the formation of type Ia supernovae.

NASA’s Chandra Observatory Finds Cosmic Showers Halt Galaxy Growth

5 March 2015 - 8:47am

Astronomers have found that the growth of galaxies containing black holes can be slowed down by a phenomenon referred to as cosmic precipitation.

Giant robot eyes scan stars for dust

4 March 2015 - 10:02am

The huge eyes of the Large Binocular Telescope in Arizona are staring across vast cosmic distances in the hope of finding signs of alien life

Dawn spacecraft set for first visit to a dwarf planet

4 March 2015 - 10:02am
The asteroid-hopping spacecraft will arrive at Ceres on Friday, making it the first to visit a dwarf planet and the first to visit two different worlds

An Old-looking Galaxy in a Young Universe

3 March 2015 - 10:32am
One of the most distant galaxies ever observed has provided astronomers with the first detection of dust in such a remote star-forming system and tantalising evidence for the rapid evolution of galaxies after the Big Bang. The new observations have used ALMA to pick up the faint glow from cold dust in the galaxy A1689-zD1 and used ESO’s Very Large Telescope to measure its distance.

Ultra-cold mirrors could reveal gravity's quantum side

3 March 2015 - 10:31am

The quantum Casimir effect is a slight attraction between two metal plates. Superconducting versions could finally show us quantum gravity at work

Bright spotlight on Ceres mission

3 March 2015 - 10:29am

As Nasa's Dawn satellite prepares to enter into orbit around the dwarf planet Ceres, scientists say they are excited to learn more about the two bright spots on its surface.

Lucky Earth survived cosmic pinball

3 March 2015 - 10:28am

How Earth survived through violent times

Rosetta catches its own shadow

3 March 2015 - 10:28am

The Rosetta satellite sees its own shadow in the highest resolution image it has so far taken of Comet 67P.

Puzzling Bright Spots on Dwarf Planet Ceres

2 March 2015 - 10:09am
Cruising through the asteroid belt, NASA Dawn spacecraft is approaching dwarf planet Ceres, and some puzzling features are coming into focus. Researchers are especially mystified by a pair of bright spots.

'Bright Spot' on Ceres Has Dimmer Companion

2 March 2015 - 10:09am
Dwarf planet Ceres continues to puzzle scientists as NASA's Dawn spacecraft gets closer to being captured into orbit around the object. The latest images from Dawn, taken nearly 29,000 miles (46,000 kilometers) from Ceres, reveal that a bright spot that stands out in previous images lies close to yet another bright area.

'Exquisite' gravity probe leaves UK

2 March 2015 - 10:02am

UK industry completes construction of the modules that make up the Lisa Pathfinder satellite - a remarkable probe that will test the key technologies needed to detect gravitational waves in space.