European Association for Astronomy Education

Source: arXiv

The addition of Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) has led to a dramatic increase in our ability to study the z > 6 Universe. The increase in the near-infrared (NIR) sensitivity of WFC3 over previous instruments has enabled us to reach apparent magnitudes approaching 29 (AB).  This allows us to probe the rest-frame ultraviolet (UV) continuum, redshifted into the NIR at z >6.

In this research the authors study the rest-UV luminosity function, and hence estimate the integrated star formation rate within 800Myr after Big Bang. Understanding the global star formation history at these redshifts is crucial in answering the question whether the UV photons produced by the short-lived OB stars were sufficient to reionize the Universe.

The studied leads to the conclusion that some reionization of the the primordial Universe seems to have been possible.

This paper was submitted to MNRAS on February 25th, 2010. (read more)

Link:

Paper submitted to MNRAS

Source: Universe Today

Itokawa, a dusty asteroid. Credit: JAXA.

Images sent back from space missions suggest that smaller asteroids are not pristine chunks of rock, but are instead covered in rubble that ranges in size from meter-sized boulders to flour-like dust. Indeed some asteroids appear to be up to 50% empty space, suggesting that they could be collections of rubble with no solid core.

But how do these asteroids form and evolve? And if we ever have to deflect one, to avoid the fate of the dinosaurs, how to do so without breaking it up, and making the danger far greater?

Johannes Diderik van der Waals (1837-1923), with a little help from Daniel Scheeres, Michael Swift, and colleagues, to the rescue. (Read more)

Source: MESSENGER Mission News

Today the MESSENGER spacecraft crossed the four-billion-mile mark since its launch. The probe has completed about 81 percent of its journey toward its destination to be the first spacecraft inserted into orbit about Mercury.

That MESSENGER’s odometer reading has reached another major milestone reminds us of the long and complex route that our spacecraft must follow. Mercury orbits deep within the Sun’s gravity well. So, even though the planet can be as close as 82 million kilometers (51 million miles) from Earth, getting the probe into orbit around Mercury depends on an innovative trajectory that uses the gravity of Earth, Venus, and Mercury itself to slow and shape the probe's descent into the inner solar system.

On its 4.9 billion-mile journey to becoming the first spacecraft to orbit the planet Mercury, MESSENGER has flown by Earth once, Venus twice, and Mercury three times. (read more)

Source: HiRISE

HiRISE has captured at least four avalanches, or debris falls, in action.

Avalanches on North Polar Scarps
Credit: NASA/JPL/University of Arizona

The image above shows the context of where these avalanches occurred, with white boxes indicating the locations of the more detailed image portions shown to the right (all images are false color). Material, likely including fine-grained ice and dust and possibly including large blocks, has detached from a towering cliff and cascaded to the gentler slopes below. The occurrence of the avalanches is spectacularly revealed by the accompanying clouds of fine material that continue to settle out of the air. The largest cloud (upper images) traces the path of the debris as it fell down the slope, hit the lower slope, and continues downhill, forming a billowing cloud front. This cloud is about 180 meters (590 feet) across and extends about 190 m (625 ft) from the base of the steep cliff. Shadows to the lower left of each cloud illustrate further that these are three dimensional features hanging in the air in front of the cliff face, and not markings on the ground (sun is from the upper right). (read more)

Source: The Kavli Foundation

Illustration of WASP-12b in orbit about its host star (Credit: ESA/C Carreau)

The class of exotic Jupiter-mass planets that orbit very close to their parent stars were not explicitly expected before their discovery. Now an international group of astrophysicists has determined that a massive planet outside our Solar System is being distorted and destroyed by its host star – a finding that helps explain the unexpectedly large size of the planet, WASP-12b.

It’s a discovery that not only explains what’s happening to WASP-12b; it also means scientists have a one-of-a-kind opportunity to observe how a planet enters this final stage of its life.

The findings were published in the February 25 issue of Nature. (read more)

Links:
arXiv
Nature

Source: ESO-eso1008 - Photo Release

NGC 346, the brightest star-forming region in the
neighbouring Small Magellanic Cloud galaxy,
some 210 000 light-years away from Earth.
Credit: ESO

This dramatic new image of the Small Magellanic Cloud (NGC 346) that will make you want to keep your eyes on the night sky. Today ESO has released a dramatic new image of NGC 346, the brightest star-forming region in our neighbouring galaxy, the Small Magellanic Cloud, 210 000 light-years away towards the constellation of Tucana (the Toucan). The light, wind and heat given off by massive stars have dispersed the glowing gas within and around this star cluster, forming a surrounding wispy nebular structure that looks like a cobweb. NGC 346, like other beautiful astronomical scenes, is a work in progress, and changes as the aeons pass. As yet more stars form from loose matter in the area, they will ignite, scattering leftover dust and gas, carving out great ripples and altering the face of this lustrous object. (read more)

Source: ESA

X-ray emission in the COSMOS field. Credit: ESA

Observations of faint and distant galaxy groups made with the European Space Agency's XMM-Newton observatory have been used to probe the evolution of dark matter. The results of the study are reported in the 20 January issue of The Astrophysical Journal. (read more)

If you enjoy worldwide astronomy events, watch out for Global Astronomy Month (GAM), running throughout April of this year. The GAM motto is “One People, One Sky” and it’s an opportunity to connect with people around the world.

For more information take a look here: www.astronomerswithoutborders.org/index.php?option=com_content&view=category&id=99&layout=blog&Itemid=149
Image credit: Astronomer’s Without Borders

If you enjoy worldwide astronomy events, watch out for Global Astronomy Month (GAM), running throughout April of this year. The GAM motto is “One People, One Sky” and it’s an opportunity to connect with people around the world.

For more information take a look here: www.astronomerswithoutborders.org/index.php?option=com_content&view=category&id=99&layout=blog&Itemid=149
Image credit: Astronomer’s Without Borders

Source: NASA

Sundogs are formed by the refracting action of plate-shaped ice crystals.
Image credit: Les Cowley/Atmospheric Optics

NASA's Solar Dynamic Observatory amazed onlookers last week when it flew past a sundog and destroyed it. Videos of the event captured shock waves from the rocket billowing through the sundog, eliciting cries of delight and amazement from the crowd below. (read more)

If you enjoy worldwide astronomy events, watch out for Global Astronomy Month (GAM), running throughout April of this year. The GAM motto is “One People, One Sky” and it’s an opportunity to connect with people around the world.

For more information take a look here: www.astronomerswithoutborders.org/index.php?option=com_content&view=category&id=99&layout=blog&Itemid=149
Image credit: Astronomer’s Without Borders

If you have a pair of binoculars or even a small telescope, you could try and follow an asteroid, Vesta, as it slowly move across the sky. The asteroid can be found in the constellation of Leo, not too far from Gamma Leo.

Happy Hunting

Image credit: Sky & Telescope

If you have a pair of binoculars or even a small telescope, you could try and follow an asteroid, Vesta, as it slowly move across the sky. The asteroid can be found in the constellation of Leo, not too far from Gamma Leo.

Happy Hunting

Image credit: Sky & Telescope

Source: NASA

Imagine holding the entire sun in the palm of your hand. Now you can. A new iPhone app developed by NASA-supported programmers delivers a live global view of the sun directly to your cell phone. Users can fly around the star, zoom in on active regions, and monitor solar activity.(read more)

Source:ESO Science Release eso1007

The Fornax dwarf galaxy. Credit: ESO.

After years of successful concealment, the most primitive stars outside our Milky Way galaxy have finally been unmasked. New observations using ESO’s Very Large Telescope have been used to solve an important astrophysical puzzle concerning the oldest stars in our galactic neighbourhood — which is crucial for our understanding of the earliest stars in the Universe. (read more)

Source: Universe Today

Asteroid Vesta as seen by NASA's Hubble Space Telescope.
Image credit: NASA/ESA/U of Md./STSci/Cornell/SWRI/UCLA

An asteroid could be visible with binoculars, or even the naked eye on Wednesday, February 17, 2010. No, it's not coming close to Earth, although this second most massive object in the asteroid belt will be at its closest point to Earth in its orbit, about 211,980,000 kilometers (131,700,000 miles) away. Asteroid Vesta – one of the asteroids that the Dawn spacecraft will visit – will be at opposition on Wednesday, meaning it is opposite the sun as seen from Earth, and is closest to us. Vesta is expected to shine at magnitude 6.1, and that brightness should make it visible for those with clear skies and a telescope, but perhaps even those blessed with excellent vision and little or no light pollution. Vesta will be visible in the eastern sky in the constellation Leo, and will continue to be visible — although less so — in the coming months. (read more)

Source: ESA

The AMS instrument's position on the ISS.
Credits: CERN et Universite de Geneve

One of the most exciting scientific instruments ever built, the Alpha Magnetic Spectrometer (AMS), arrived at ESA's Test Centre in the Netherlands for testing before being launched on the Space Shuttle to the ISS this July.

The quest for the origins of the Universe is about to take a step further in the Large Space Simulator (LSS) at ESA's research and technology centre, ESTEC, in Noordwijk, the Netherlands, under responsibility of Agency's Directorate of Human Spaceflight.

The LSS is used to test satellites and spacecraft before they are sent to space and has seen all kinds of space hardware, but the AMS detector is still very special. Not only is it the biggest scientific instrument to be installed on the International Space Station (ISS), but also it is the first magnetic spectrometer to be flown in space, and the largest cryogenically cooled superconducting magnet ever used in space.

AMS will help scientists to understand better the fundamental issues on the origin and structure of the Universe by observing 'antimatter' and 'dark matter'. As a byproduct, AMS will gather a lot of other information from cosmic radiation sources such as stars and galaxies millions of light years from our home galaxy. Not only astronomers, but also particle physicists are waiting for AMS data.

The AMS project is led by Nobel laureate Samuel Ting, from the Massachusetts Institute of Technology (MIT), and involves an international team composed of 56 institutes from 16 countries. ESA is a partner in the AMS collaboration through the Directorate of Human Spaceflight. The first version of the experiment, AMS-01, was flown in June 1998 aboard the Space Shuttle Discovery and, after promising results, the bigger and more capable version was accepted to be flown on the ISS.(read more)

Source: ESA

Phobos image was obtained by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express on 28 July 2008 (orbit 5870), at a distance of 351 km from the moon’s centre.

Today Mars Express began a series of flybys of Phobos, the largest moon of Mars. The campaign will reach its crescendo on 3 March, when the spacecraft will set a new record for the closest pass to Phobos, skimming the surface at just 50 km. The data collected could help untangle the origin of this mysterious moon.(read more)

Source:ESO Photo Release eso1006

The Orion Nebula reveals many of its hidden secrets in a dramatic image taken by ESO’s new VISTA survey telescope. The telescope’s huge field of view can show the full splendour of the whole nebula and VISTA’s infrared vision also allows it to peer deeply into dusty regions that are normally hidden and expose the curious behaviour of the very active young stars buried there.(read more)

Note: this post is adapted from Weekend SkyWatcher's Forecast by Tammy Plotner on Universe Today, http://www.universetoday.com/

If you are ready for a challenge why not try spotting 11.8 magnitude Comet Tritton! Now cruising through the constellation of Aries (RA 1h 53.5m Dec 17° 39'), this faint fuzzy won't be the easiest of targets to spot – but then it wouldn't be a challenge, would it? Comet 157P Tritton was discovered by Keith Tritton (U. K. Schmidt Telescope Unit, Coonabarabran) on February 11, 1978. Now, almost 32 years later to the date, it's back again on its every 6.33 year journey around our Sun. Although it won't reach perihelion (closest position to the sun) until February 20, its original estimated return brightness was only expected to reach magnitude 16 and now it is far exceeding expectations. Don't expect to see a flaming ball exhibiting a tail because that's not going to happen… but congratulate yourself if you can find this faint fuzzy in the sky.

Image credit: Universe Today