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The Gaia mission of the European Space Agency (ESA) has taken a step forward with the digital camera placement largest ever built for a space mission consists of 106 charge-coupled device high sensitivity. This matrix of pixels billion will be the eye of Gaia , a satellite designed to map the Milky Way and whose mission work together over 400 European scientists, including thirty researchers and technicians from the Department of Astronomy and Meteorology University of Barcelona .
(Technical Astrium France in Toulouse, working on the assembly of mosaic CCD on the satellite ‘Gaia’. Image: Astrium.)
The human eye can see at a glance several thousand stars on a clear night. Gaia will be able to study one billion stars within the Milky Way and neighboring galaxies, over the five year duration of its mission . This way, you create a catalog record which specify the brightness, spectral characteristics and three-dimensional position and displacement of each object observed.
To study the most distant stars, whose brightness is about a million times smaller than the human eye can detect, Gaia has a CCD detector consists of 106, an advanced version of the sensors can be found in the conventional digital cameras. The detector designed for the mission Gaia is formed by 106 CCD developed specifically for this mission by the company e2v Technologies, Chelmsford, UK. Each of them is a bit smaller than a credit card (4.7 x 6 cm) and thinner than a human hair.
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As the Search Easter eggs in the tall grass of a garden, hunting for the most massive stars of Milky Way Application of the eyes and perseverance. In their research, astronomers using powerful telescopes sensitive to X rays and radiation Infrared to find traces of a large population of massive stars that emit X-rays
The image above shows the infrared data of Spitzer Space Telescope of NASA at Neighbourhood the plane of the galaxy. The two dark rectangles contain the photographs of artificially darkened data Spitzer, in order to identify the sources of X rays (in blue) detected at the center of each by the space observatory Chandra. Each X-ray source coincides with a signal intense in the infrared.
The analysis of X-ray and infrared data, as well as optical and radio observations reveal that these light sources are, in fact, extremely massive stars. Two other massive stars were also found near the plane of the Milky Way using similar methods. Of comments performed through telescope ESA’s XMM-Newton have provided valuable information on these two objects. It is believed that these four stars must be at least 25 times mass that Sun and lie between 7500 and 18 000 years light of Earth. The lifetime of these stars do not exceed a few million years and they disappear as supernovae.
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Two U.S. astronomers have discovered that small and faint stars known as red dwarfs are much more prolific than previously thought. So much so that experts say is likely that the total number of stars in the universe is three times higher than that previously thought. The study appears this week in the journal Nature.
Red dwarfs are relatively small and dim compared to stars like our Sun, and so astronomers were not able to detect so far in different galaxies to the Milky Way or in their nearest neighbors. For this reason scientists did not know the proportion of red dwarfs are within the stellar population of the universe.
Two astronomers from the Universities of Yale and Princeton (USA) have used instruments powerful Keck Observatory in Hawaii to detect the faint traces of red dwarfs in eight relatively nearby massive galaxies. Elliptical galaxies is located between 50 and 300 million light years away.
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Chinese and French scientists from CNRS and Observatories National Academy of Sciences (NAOC) recently published the results of their research into cosmic environment close – a quarantine of galaxies that surround us – and on formation of the Andromeda Galaxy, there are six billion years.
This collaboration has involved the Laboratoire Galaxies, stars, physics and instrumentation GEPI (Observatoire de Paris / CNRS / Universite Paris Diderot) and National Astronomical Observatories of Chinese Academy of Sciences (National Astronomical Observatories, Chinese Academy of Sciences – NAOC – ) with the support of the International Associated Laboratory “Origins” (CNRS, Observatoire de Paris, Université Pierre et Marie Curie, Universite Paris Diderot, NAOC), established October 22, 2008 in Beijing.
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A statistical study suggests that solar-type star out of four would have a planet the size of Earth.
[Fig:A new study indicates that small extrasolar planets are more common than big ones. Extrapolating that 23 percent of solar-type stars would be equipped with an Earth-like planet.]
We know today about 500 planets orbiting other stars. But it could be billions in the Milky Way. This is shown in a large study, both by the size of the sample by the sensitivity measurements, conducted by Andrew Howard of the University of California, and colleagues.
Five long years, they studied with the Keck telescope 10 meters in diameter, Hawaii, 166 G-type stars (similar to the Sun) and K (smaller and more “red”) within a radius of 80 light years . The goal: to observe any planets from 3 to more than 1000 times the mass of Earth, orbiting close around these stars (within 0.25 astronomical unit, or a quarter of the Earth-Sun distance). The gravitational pull of a planet orbiting prints indeed a periodic motion in his star, who is betrayed by a shift in the wavelength of its radiation (radial velocity method).
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Fermi telescope from NASA, a gamma-ray space observatory has discovered two huge bubbles, about 25,000 light years each, located above and below the center of the Milky Way. This is a hitherto unknown structure in our galaxy and could correspond to remnants of an eruption of a giant black hole.
“What we see are two bubbles that emit gamma rays and extending 25,000 light years to the north and south of the center of the galaxy,” says Doug Finkbeiner, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge (Massachusetts, USA), which was the first to recognize. “We still do not fully understand their nature and origin.”
The structure spans more than half the visible sky from the constellation of Virgo to the constellation of the Crane, and may be millions of years old. An article with the results of the study has been accepted for publication in The Astrophysical Journal.
Finkbeiner and his team discovered the bubbles public data processing Large Area Telescope (LAT, for its acronym in English) of Fermi. The LAT’s gamma ray detector is more sensitive and higher resolution released so far. This type of rays are the most energetic form of light.
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Many of the oldest stars in the Milky Way are former members of other smaller galaxies that were destroyed by violent galactic collisions for about five billion years, according to a new study.
A team of scientists at the Institute for Computational Cosmology, University of Durham, UK, and colleagues at Max Planck Institute for Astrophysics in Germany, and University of Groningen in the Netherlands, carried out extensive computer simulations to recreate the beginnings of our galaxy.
The simulations revealed that the oldest stars, which are found in the stellar halo “debris” surrounding the Milky Way, were probably torn from the smaller galaxies by the gravitational forces acting during the collision of galaxies.
Cosmologists believe that the early universe was filled with small galaxies of short and violent life. These galaxies collided with each other leaving “debris,” which ended up being part of galaxies like the Milky Way.
The researchers believe their finding supports the theory that many of the oldest stars in the Milky Way to other galaxies belonged instead of being the first stars were born within our own, when it started forming for about 10,000 million years .
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For the first time, a team of astronomers has been successful in investigating the earliest stages of the evolutionary history of our galaxy, the Milky Way. Scientists at the Institute of Astronomy Argelander at the University of Bonn and Max-Planck Institute for Radio Astronomy in Bonn, have concluded that our galaxy moved from its original homogenous state to a lumpy in just a few hundred million years.
The team of Pavel Kroupa and Michael Marks studied spherical groups of stars (globular clusters) found in the halo of the Milky Way, outside the spiral arms in one of which is the sun Every one of those globular clusters containing hundreds of thousands of stars and is believed to have formed at the same time as the protogalaxy that eventually became the Milky Way today.
Globular star clusters can be considered as fossils of early history of the galaxy, as has been shown that these clusters retain traces of the conditions under which they formed. The stars of the clusters were formed from a cloud of molecular gas (hydrogen relatively cold), which is not completely exhausted in the process of star formation. The residual gas was expelled by the winds and radiation from the newborn population of stars.
Due to this expulsion of gas, globular clusters underwent a process in which they lost to the stars that formed in its borders. This means that the current appearance of the clusters was directly influenced by what happened in his childhood.
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The computers of some of the hundreds of thousands of volunteers who give their teams within the collaborative computational project ‘Einstein @ Home ‘ (Einstein at home) have uncovered a new and rare press in the Milky Way . The data has provided the Arecibo Observatory ( Puerto Rico).
Citizens Chris and Helen Colvin, Ames ( Iowa, USA), and Daniel Gebhardt , University of Mainz ( Musikinformatik , Germany ) were the three volunteers Einstein @ Home project (Einstein at home ) which have been recognized “officially “the discovery of a new push in the Milky Way . But all three are part of a much larger group that give the capacity of their computers when not working.
Their computers , along with another 500,000 worldwide , analyze data to Einstein @ Home , which uses computer time donated homes and offices of 250,000 volunteers in 192 different countries (on average donors provide two computers per person) .
The three volunteers have discovered radio waves of a new pulsar hidden in data collected by the Arecibo Observatory in Puerto Rico. This is the first discovery in deep space for Einstein @ Home.
The new pulsar , called PSR J2007 +2722 is a neutron star that makes 41 rotations per second. It is located in the Milky Way about 17,000 light years from Earth in the constellation Vulpecula. Unlike most pulsars that spin so fast and uniform , PSR J2007 +2722 is only in space , with no other stars orbiting close to him.
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A team of astronomers has completed a high-precision study of one of the young star clusters more massive of the Milky Way. To do this, researchers compared two observations made with ten years of separation. The result was unexpected.
Open star clusters, like the famous Pleiades, will not stay with their stars grouped forever. In the course of tens of millions of years, the stars within them will be scattered.
Something very different happens with compact clusters. In these clusters, the stars tend to remain gravitationally bound together over billions of years.
With a huge amount of adding stars among a mass of more than 10,000 suns, and bonded in a volume with a diameter of only three light-years, the cluster of young stars in the giant nebula NGC 3603 is one of the star clusters most compact of the Milky Way. In comparison, the volume of space with 3 light years in diameter that is located in the Sun, there is no other star.
Could this compact open cluster as a globular cluster in formation?
To unravel this issue, a team of astronomers from the University of Cologne and the Max Planck Institute for Astronomy in Heidelberg, including Rochau Boyke Wolfgang Brandner and followed the movement of hundreds of stars in the cluster. This kind of tracking can reveal whether the stars are in the process of separating or, on the contrary, are intended to be gravitationally bound to each other for a long time.
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The image above shows the infrared data of Spitzer Space Telescope of NASA at Neighbourhood the plane of the galaxy. The two dark rectangles contain the photographs of artificially darkened data Spitzer, in order to identify the sources of X rays (in blue) detected at the center of each by the space observatory Chandra. Each X-ray source coincides with a signal intense in the infrared.
[Fig:A new study indicates that small extrasolar planets are more common than big ones. Extrapolating that 23 percent of solar-type stars would be equipped with an Earth-like planet.]