Institute of Astronomy

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Beasts of the Southern Wild. Discovery of a large number of Ultra Faint satellites in the vicinity of the Magellanic Clouds. (arXiv:1503.02079v1 [astro-ph.GA])

Astronomy News - 10 March 2015 - 10:22am

We have used the publicly released Dark Energy Survey data to hunt for new satellites of the Milky Way in the Southern hemisphere. Our search yielded a large number of promising candidates. In this paper, we announce the discovery of 9 new unambiguous ultra-faint objects, whose authenticity can be established with the DES data alone. Based on the morphological properties, three of the new satellites are dwarf galaxies, one of which is located at the very outskirts of the Milky Way, at a distance of 380 kpc. The remaining 6 objects have sizes and luminosities comparable to the Segue 1 satellite and can not be classified straightforwardly without follow-up spectroscopic observations. The satellites we have discovered cluster around the LMC and the SMC. We show that such spatial distribution is unlikely under the assumption of isotropy, and, therefore, conclude that at least some of the new satellites must have been associated with the Magellanic Clouds in the past.

Key to quantum gravity may lurk in cosmic haze

Astronomy News - 7 March 2015 - 9:18am
Any blurry observations of distant objects could suggest the universe itself is blurry at a minute scale, and hint at how to build a theory of quantum gravity






Introducing the NAVCAM image browser

Astronomy News - 7 March 2015 - 9:17am

The first set of images from Rosetta's NAVCAM has been made available to all users via ESA’s Planetary Science Archive (PSA). This first batch of image data covers the period leading up to 2 July 2014, prior to Rosetta's arrival at comet 67P/C-G. Further releases of image data will be made in blocks on a monthly basis henceforth, with the near-term aim to catch-up so that NAVCAM data will be publicly released six months after they are taken.

NASA Spacecraft Becomes First to Orbit a Dwarf Planet

Astronomy News - 7 March 2015 - 9:15am

NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000) kilometers from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday.

VIDEO: The Ceres space probe - in 60 secs

Astronomy News - 7 March 2015 - 9:13am

The US space agency's Dawn probe is set to go into orbit around Ceres. What will it find there?

Mars: The Planet that Lost an Ocean’s Worth of Water

Astronomy News - 6 March 2015 - 10:09am
A primitive ocean on Mars held more water than Earth’s Arctic Ocean, and covered a greater portion of the planet’s surface than the Atlantic Ocean does on Earth, according to new results published today. An international team of scientists used ESO’s Very Large Telescope, along with instruments at the W. M. Keck Observatory and the NASA Infrared Telescope Facility, to monitor the atmosphere of the planet and map out the properties of the water in different parts of Mars’s atmosphere over a six-year period. These new maps are the first of their kind. The results appear online in the journal Science today.

SOHO's 3000th comet - contest

Astronomy News - 6 March 2015 - 10:08am

It may have been designed to probe and monitor the Sun, but the ESA/NASA Solar and Heliospheric Observatory (SOHO) has also found fame as a comet finder. A record-breaking 2890 comets have been discovered with SOHO since its launch in 1995, more than any other comet hunter in history!

An explosive quartet - Hubble sees multiple images of a supernova for the very first time [heic1505]

Astronomy News - 6 March 2015 - 10:07am

Astronomers using the NASA/ESA Hubble Space Telescope have, for the first time, spotted four images of a distant exploding star. The images are arranged in a cross-shaped pattern by the powerful gravity of a foreground galaxy embedded in a massive cluster of galaxies. The supernova discovery paper will appear on 6 March 2015 in a special issue of Science celebrating the centenary of Albert Einstein's theory of general relativity.

Hubble Sees Supernova Split into Four Images by Cosmic Lens

Astronomy News - 6 March 2015 - 10:07am

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Three-leaf clover plants abound everywhere: on lawns, in gardens, and in forests. But spotting a four-leaf clover is a rare, lucky find. Astronomers using the Hubble Space Telescope have found the equivalent of a four-leaf clover with the discovery of four images of the same supernova. The images are arranged around a giant foreground elliptical galaxy embedded in a cluster of galaxies. The arrangement forms a cross-shaped pattern called an Einstein Cross. The powerful gravity from both the elliptical galaxy and its galaxy cluster magnifies the light from the supernova behind them in an effect called gravitational lensing. The elliptical galaxy and its galaxy cluster, MACS J1149.6+2223, are 5 billion light-years away from Earth. The supernova behind it is 9.3 billion light-years away.

NASA Research Suggests Mars Once Had More Water than Earth’s Arctic Ocean

Astronomy News - 6 March 2015 - 10:06am

A primitive ocean on Mars held more water than Earth’s Arctic Ocean, according to NASA scientists who, using ground-based observatories, measured water signatures in the Red Planet’s atmosphere.

Fast star first fled from a supernova, now the galaxy

Astronomy News - 6 March 2015 - 10:06am
The fastest star in the Milky Way is high-tailing it out of here at 1200 kilometres a second after surviving its sibling star's death as a massive supernova






Dawn probe set for Ceres arrival

Astronomy News - 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

Astronomy News - 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

Astronomy News - 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

Astronomy News - 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

Astronomy News - 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

Astronomy News - 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

Astronomy News - 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

Astronomy News - 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

Astronomy News - 3 March 2015 - 10:28am

How Earth survived through violent times