European Association for Astronomy Education

Source: New Scientist

Making a black hole let go of anything is a tall order. But their grip may slowly weaken if the universe has extra dimensions, something that pulsars could help us to test.

String theory, which attempts to unify all the known forces, calls for extra spatial dimensions beyond the three we experience. Testing the theory has proved difficult, however.

Now John Simonetti of Virginia Tech in Blacksburg and colleagues say black holes orbited by neutron stars called pulsars could do just that - if cosmic surveys can locate such pairings. "The universe contains 'experimental' setups we cannot produce on Earth," he says.

Black holes are predicted to fritter away their mass over time by emitting particles, a phenomenon called Hawking radiation. Without extra dimensions, this process is predicted to be agonisingly slow for run-of-the-mill black holes weighing a few times as much as the sun, making it impossible to measure.

Extra dimensions would give the particles more ways to escape, speeding up the process. This rapid weight loss would loosen a black hole's gravitational grip on any orbiting objects, causing them to spiral outwards by a few metres per year, the team calculates (The Astrophysical Journal, DOI: 10.1088/2041-8205/737/2/l28).

A pulsar orbiting a black hole could reveal this distancing. That's because the lighthouse-like pulses of radiation they emit would vary slightly depending on the size of the star's orbit. (read source)

Source: ESO

Lyman-alpha blob LAB-1. Image credits: ESO/M. Hayes.

Observations from ESO’s Very Large Telescope have shed light on the power source of a rare vast cloud of glowing gas in the early Universe. The observations show for the first time that this giant “Lyman-alpha blob” — one of the largest single objects known — must be powered by galaxies embedded within it. The results appear in the 18 August issue of the journal Nature.(read more)

Source: University of Warwick

University of Warwick physicist has produced a galaxy sized solution which explains one of the outstanding puzzles of particle physics, while leaving the door open to the related conundrum of why different amounts of matter and antimatter seem to have survived the birth of our Universe.

Physicists would like a neat universe where the laws of physics are so universal that every particle and its antiparticle behave in the same way. However in recent years experimental observations of particles known as Kaons and B Mesons have revealed significant differences in how their matter and anti matter versions decay.

This “Charge Parity violation” or “CP violation” is an awkward anomaly for some researchers but is a useful phenomenon for others as it may open up a way of explaining why more matter than anti matter appears to have survived the birth of our universe.

However Dr Mark Hadley, of the Department of Physics at the University of Warwick, believes he has found a testable explanation for apparent Charge Parity violation that preserves parity but also makes the Charge Parity violation an even more plausible explanation for the split between matter and antimatter.

Dr Hadley’s paper (just published in EPL (Europhysics Letters) and entitled “The asymmetric Kerr metric as a source of CP violation”) suggests that researchers have neglected the significant impact of the rotation of our Galaxy on the pattern of how sub atomic particles breakdown. (read more)

Source: ESO Science Release eso1124

COSMOS field imaged by the Canada France Hawaii Telescope (CFHT).
Image credits: CFHT/IAP/Terapix/CNRS/ESO.

A new study combining data from ESO’s Very Large Telescope and ESA’s XMM-Newton X-ray space observatory has turned up a surprise. Most of the huge black holes in the centres of galaxies in the past 11 billion years were not turned on by mergers between galaxies, as had been previously thought. (read more)

Source: University of Michigan

Spiral galaxy NGC 300. Image credit:ESO.

Physicists and astronomers have long believed that the universe has mirror symmetry, like a basketball. But recent findings from the University of Michigan suggest that the shape of the Big Bang might be more complicated than previously thought, and that the early universe spun on an axis.(read more)

Source: ESA

Integral gamma-ray observatory.
Image credits: ESA/Medialab

ESA’s Integral gamma-ray observatory has provided results that will dramatically affect the search for physics beyond Einstein. It has shown that any underlying quantum ‘graininess’ of space must be at much smaller scales than previously predicted.(read more)

Source: ESO Science Release eso1122

An artist’s rendering of the most distant quasar.
Image credit: ESO/M. Kornmesser.

A team of European astronomers has used ESO’s Very Large Telescope and a host of other telescopes to discover and study the most distant quasar found to date. This brilliant beacon, powered by a black hole with a mass two billion times that of the Sun, is by far the brightest object yet discovered in the early Universe. The results will appear in the 30 June 2011 issue of the journal Nature. (read more)

Source: Daily Galaxy

An Unitary Triangle fit measurements of CP violation and rare decays. Image source: UTfit

Scientists of the MINOS experiment at the Department of Energy’s Fermi National AcceleratorLaboratory have announced the results from a search for a rare phenomenon, the transformation of muon neutrinos into electron neutrinos. The result is consistent with and significantly constrains a measurement reported 10 days ago by the Japanese T2K experiment, which could have implications for our understanding of the role that neutrinos may have played in the evolution of the universe. If muon neutrinos transform into electron neutrinos, neutrinos could be the reason that the big bang produced more matter than antimatter, leading to the universe as it exists today. (read more)

Source: Chandra X-Ray Observatory

Illustration of Baby Black Hole.
Image credit: NASA/CXC/A.Hobart.

A composite image from NASA's Chandra X-ray Observatory and Hubble Space Telescope (HST) combines the deepest X-ray, optical and infrared views of the sky. Using these images, astronomers have obtained the first direct evidence that black holes are common in the early Universe and shown that very young black holes grew more aggressively than previously thought. (read more)

Source: ESA Online Videos

Over 1.5 million kilometres from Earth, ESA's Herschel space telescope has been observing the Universe for the last two years, studying the infrared radiation emitted by the coldest bodies in the cosmos. See the invisible in this edition of Space.

Source: IOP.

Physicists at CERN's Large Hadron Collider (LHC) are confident that they can find the Higgs boson by the end of 2012, when the machine will be shut down temporarily. (learn more)

Source: PhysOrg.com

Individual young stars and star clusters in the 'dead' elliptical galaxy, Messier 105

University of Michigan astronomers examined old galaxies and were surprised to discover that they are still making new stars. The results provide insights into how galaxies evolve with time.

Related links:
Universe Today

Source: SpaceTelescope

V1 in M31.
Image credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)

Though the Universe is filled with billions upon billions of stars, the NASA/ESA Hubble Space Telescope has been trained on a single variable star that in 1923 altered the course of modern astronomy. And, at least one famous astronomer of the time lamented that the discovery had shattered his world view.

The star goes by the inauspicious name of Hubble variable number one, or V1, and resides two million light-years away in the outer regions of the neighbouring Andromeda galaxy, or M31. V1 is a special class of pulsating star called a Cepheid variable that can be used to make reliable measurements of large cosmic distances.

The star helped Edwin Hubble show that Andromeda lies beyond our galaxy. Prior to the discovery of V1 many astronomers, including Harlow Shapley, thought spiral nebulae, such as Andromeda, were part of our Milky Way galaxy. Others weren't so sure. In fact, Shapley and Heber Curtis held a public debate in 1920 over the nature of these nebulae. But it took Edwin Hubble's discovery just a few years later to settle the debate.

Hubble sent a letter, along with a light curve of V1, to Shapley telling him of his discovery. After reading the note, Shapley reportedly told a colleague, "Here is the letter that destroyed my Universe." The Universe became a much bigger place after Edwin Hubble's discovery.

In commemoration of this landmark observation, astronomers with the Space Telescope Science Institute's Hubble Heritage Project partnered with the American Association of Variable Star Observers (AAVSO) to study the star. AAVSO observers followed V1 for six months, producing a plot, or light curve, of the rhythmic rise and fall of the star's light. Based on this data, the Hubble Heritage team scheduled Hubble telescope time to capture Wide Field Camera 3 images of the star at its dimmest and brightest light levels.

These observations were presented on 23 May at the meeting of the American Astronomical Society in Boston.

Source: SPACE.com

Astronomers have created the most complete 3-D map of our local universe, revealing new details about our place in the cosmos. The map shows all visible structures out to about 380 million light-years, which includes about 45,000 of our neighboring galaxies (the diameter of the Milky Way is about 100,000 light-years across).(read more)

Source: Physics World

New results from NASA's Fermi Gamma-Ray Space Telescope appear to confirm a larger-than-expected rate of high-energy positrons reaching the Earth from outer space. This anomaly in the cosmic-ray flux was first observed by the Italian-led PAMELA spacecraft in 2008 and suggests the existence of annihilating dark-matter particles. (read more)

Source: Royal Astronomical Society

Artist’s impression of  jets emerging from a supermassive black hole.
Credit: Dana Berry / STScI

Two UK astronomers have found that the giant black holes in the centre of galaxies are on average spinning faster than at any time in the history of the Universe. Dr Alejo Martinez-Sansigre of the University of Portsmouth and Prof. Steve Rawlings of the University of Oxford made the new discovery by using radio, optical and X-ray data. They publish their findings in the journal Monthly Notices of the Royal Astronomical Society.(read more)

Source: ESA/Hubble Science Release heic1106

Image credit: NASA, ESA, J. Richard (CRAL) and J.-P. Kneib (LAM). Acknowledgement: Marc Postman (STScI)

Using the amplifying power of a cosmic gravitational lens, astronomers have discovered a distant galaxy whose stars  were born unexpectedly early in cosmic history. This result sheds new light on the formation of the first galaxies, as well as on the early evolution of the Universe. (read more)

Source: NASA-Astro-E2 Mission

Artist's conception of Suzaku in orbit. Image credit: ISAS/JAXA

X-ray observations made by the Suzaku observatory provide the clearest picture to date of the size, mass and chemical content of a nearby cluster of galaxies. The study also provides the first direct evidence that million-degree gas clouds are tightly gathered in the cluster's outskirts.

Suzaku is sponsored by the Japan Aerospace Exploration Agency (JAXA) with contributions from NASA and participation by the  international scientific community. The findings will appear in the March 25 issue of the journal Science.

Galaxy clusters are millions of light-years across, and most of their normal matter comes in the form of hot X-ray-emitting gas that fills the space between the galaxies.(read more)

Source: ESA

LISA will comprise three satellites, linked by lasers across five million km of
space, to track very slight spacetime distortion caused by gravitational waves.
Image credits: AEI/MildeMarketing/Exozet.

A key technical challenge of the joint ESA-NASA LISA mission has been solved: how to maintain precise pointing of a laser beam across five million km of space.(read more)

Source: Hubble/ESA

Pushing the Hubble Space Telescope to the limit of its technical ability, an international collaboration of astronomers have found what is likely to be the most distant and ancient galaxy ever seen, whose light has taken 13.2 billion years to reach us (a redshift of around 10).(read more)