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  • richardmitnick 11:35 am on September 5, 2014 Permalink | Reply
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    From Science Daily: “‘Brightpoints': New clues to determining the solar cycle” 

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    Science Daily

    September 3, 2014
    NASA

    Approximately every 11 years, the sun undergoes a complete personality change from quiet and calm to violently active. The height of the sun’s activity, known as solar maximum, is a time of numerous sunspots, punctuated with profound eruptions that send radiation and solar particles out into the far reaches of space.

    sun
    A composite of 25 separate images from NASA’s SDO, spanning one year from April 2012 to April 2013. The image reveals the migration tracks of active regions towards the equator during that period.
    Credit: NASA/SDO/Goddard

    However, the timing of the solar cycle is far from precise. Since humans began regularly recording sunspots in the 17th century, the time between successive solar maxima has been as short as nine years, but as long as 14, making it hard to determine its cause. Now, researchers have discovered a new marker to track the course of the solar cycle — brightpoints, little bright spots in the solar atmosphere that allow us to observe the constant roiling of material inside the sun. These markers provide a new way to watch the way the magnetic fields evolve and move through our closest star. They also show that a substantial adjustment to established theories about what drives this mysterious cycle may be needed.

    Historically, theories about what’s going on inside the sun to drive the solar cycle have relied on only one set of observations: the detection of sunspots, a data record that goes back centuries. Over the past few decades, realizing that sunspots are areas of intense magnetic fields, researchers have also been able to include observations of magnetic measurements of the sun from more than 90 million miles away.

    “Sunspots have been the perennial marker for understanding the mechanisms that rule the sun’s interior,” said Scott McIntosh, a space scientist at the National Center for Atmospheric Research in Boulder, Colorado, and first author of a paper on these results that appears in the September 1, 2014, issue of the Astrophysical Journal. “But the processes that make sunspots are not well understood, and far less, those that govern their migration and what drives their movement. Now we can see there are bright points in the solar atmosphere, which act like buoys anchored to what’s going on much deeper down. They help us develop a different picture of the interior of the sun.”

    Over the course of a solar cycle, the sunspots tend to migrate progressively lower in latitude, moving toward the equator. The prevailing theory is that two symmetrical, grand loops of material in each solar hemisphere, like huge conveyor belts, sweep from the poles to the equator where they sink deeper down into the sun and then make their way steadily back to the poles. These conveyor belts also move the magnetic field through the churning solar atmosphere. The theory suggests that sunspots move in synch with this flow — tracking sunspots has allowed a study of that flow and theories about the solar cycle have developed based on that progression. But there is much that remains unknown: Why do the sunspots only appear lower than about 30 degrees? What causes the sunspots of consecutive cycles to abruptly flip magnetic polarity from positive to negative, or vice versa? Why is the timing of the cycle so variable?

    Beginning in 2010, McIntosh and his colleagues began tracking the size of different magnetically balanced areas on the sun, that is, areas where there are an equal number of magnetic fields pointing down into the sun as pointing out. The team found magnetic parcels in sizes that had been seen before, but also spotted much larger parcels than those previously noted — about the diameter of Jupiter. The researchers also looked at these regions in imagery of the sun’s atmosphere, the corona, captured by NASA’s Solar Dynamics Observatory, or SDO. They noticed that ubiquitous spots of extreme ultraviolet and X-ray light, known as brightpoints, prefer to hover around the vertices of these large areas, dubbed “g-nodes” because of their giant scale.

    These brightpoints and g-nodes, therefore, open up a whole new way to track how material flows inside the sun. McIntosh and his colleagues then collected information about the movement of these features over the past 18 years of available observations from the joint European Space Agency and NASA Solar and Heliospheric Observatory and SDO to monitor how the last solar cycle progressed and the current one started. They found that bands of these markers — and therefore the corresponding large magnetic fields underneath — also moved steadily toward the equator over time, along the same path as sunspots, but beginning at a latitude of about 55 degrees. In addition, each hemisphere of the sun usually has more than one of these bands present.

    McIntosh explains that a complex interaction of magnetic field lines may take place in the sun’s interior that is largely hidden from view. The recent observations suggest that the sun is populated with bands of differently polarized magnetic material that, once they form, steadily move toward the equator from high latitudes. These bands will either have a northern or southern magnetic polarity and their sign alternates in each hemisphere such that the polarities always cancel. For example, looking at the sun’s northern hemisphere, the band closest to the equator — perhaps of northern polarity — would have magnetic field lines that connect it to another band, at higher latitudes, of southern polarity. Across the equator, in the bottom half of the sun, a similar process occurs, but the bands would be an almost mirror image of those across the equator, southern polarity near the equator and northern at higher latitudes. Magnetic field lines would connect the four bands; inside each hemisphere and across the equator as well.

    While the field lines remain relatively short like this, the sun’s magnetic system is calmer, producing fewer sunspots and fewer eruptions. This is solar minimum. But once the two low-latitude marching bands reach the equator their polarities essentially cancel each other out. Abruptly they disappear. This process, from migratory start to finish at the equator takes 19 years on average, but is seen to vary from 16 to about 21 years.

    Following the equatorial battle and cancellation, the sun is left with just two large bands that have migrated to about 30 degrees latitude. The magnetic field lines from these bands are much longer and so the bands in each hemisphere feel less of each other. At this point, the sunspots begin to grow rapidly on the bands, beginning the ramp-up to solar max. The growth only lasts so long, however, because the process of generating a new band of opposite polarity has already begun at high latitudes. When that new band begins to appear, the complex four-band connection starts over and the number of sunspots starts to decrease on the low-latitude bands.

    In this scenario, it is the magnetic band’s cycle — the lifetime of each band as it marches toward the equator — that truly defines the entire solar cycle. “Thus, the 11-year solar cycle can be viewed as the overlap between two much longer cycles,” said Robert Leamon, co-author on the paper at Montana State University in Bozeman and NASA Headquarters in Washington.

    The new conceptual model also provides an explanation of why sunspots are trapped below 30 degrees and abruptly change sign. However, the model creates a question about a different latitude line: Why do the magnetic markers, the brightpoints and g-nodes, start appearing at 55 degrees?

    “Above that latitude, the solar atmosphere appears to be disconnected from the rotation beneath it,” said McIntosh. “So there is reason to believe that, inside the sun, there’s a very different internal motion and evolution at high latitudes compared to the region near the equator. 55-degrees seems to be a critical latitude for the sun and something we need to explore further.”

    Solar cycles theories are best tested by making predictions as to when we will see the next solar minimum and the next solar maximum. This research paper forecasts that the sun will enter solar minimum somewhere in the last half of 2017, with the sunspots of the next cycle appearing near the end of 2019.

    “People make their predictions for when this solar cycle will end and the next one will start,” said Leamon. “Sometime in 2019 or 2020, some people will be proved right and others wrong.”

    In the meantime, regardless of whether the new hypothesis provided by McIntosh and his colleagues is correct, this long term set of bright points and g-node locations offers a new set of observations to explore the drivers of solar activity beyond only sunspots. Inserting this information into solar models will provide an opportunity to improve simulations of our star. Such advanced models tell us more about other stars too, leading to a better understanding of similar magnetic activity on more exotic, distant celestial counterparts.

    See the full article here.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.

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  • richardmitnick 8:55 pm on August 16, 2014 Permalink | Reply
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    From Science Daily- “Dark bands in starlight: New Milky Way maps help solve stubborn interstellar material mystery” 

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    Science Daily

    August 14, 2014
    Originally by Phil Sneiderman, Johns Hopkins University

    An international team of sky scholars, including a key researcher from Johns Hopkins, has produced new maps of the material located between the stars in the Milky Way. The results should move astronomers closer to cracking a stardust puzzle that has vexed them for nearly a century.

    The maps and an accompanying journal article appear in the Aug. 15 issue of the journal Science. The researchers say their work demonstrates a new way of uncovering the location and eventually the composition of the interstellar medium — the material found in the vast expanse between star systems within a galaxy.

    This material includes dust and gas composed of atoms and molecules that are left behind when a star dies. The material also supplies the building blocks for new stars and planets.

    “There’s an old saying that ‘We are all stardust,’ since all chemical elements heavier than helium are produced in stars,” said Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a prominent role in the research and helped shape the Science paper. “But we still don’t know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form.”

    In particular, the researchers focused on a mysterious feature in the light from stars, a peculiarity called diffuse interstellar bands, or “DIBS.” A graduate student [astronomer Mary Lea Heger] who photographed the light from distant stars discovered these dark bands in 1922.

    bands

    Analyzing rainbow-colored bands of starlight that have passed through space gives astronomers important information about the makeup of the space materials that the light has encountered. But in 1922, the grad student’s photographs yielded some dark lines indicating that some starlight was “missing” and that something in the interstellar medium between Earth and the star was absorbing the light.

    Since then, scientists have identified more than 400 of these diffuse interstellar bands, but the materials that cause the bands to appear and their precise location have remained a mystery.

    Researchers have speculated that the absorption of starlight that creates these dark bands points to the presence of unusually large complex molecules, but proof of this has remained elusive. The nature of this puzzling material is important to astronomers because it could provide clues about the physical conditions and chemistry of these regions between stars. Such details serve as critical components in theories as to how stars and galaxies are formed.

    Wyse said more concrete clues should emerge from the new pseudo-3D maps of the DIB-material within our Milky Way Galaxy, maps that were produced by the 23 scientists who contributed to the Science article.

    The maps were assembled from data collected over a 10-year period by the Radial Velocity Experiment, also known as RAVE. This project used the UK Schmidt Telescope in Australia to collect spectroscopic information from the light of as many as 150 stars at once. The maps are described as “pseudo-3D” because a specific mathematical form was assumed for the distribution in the vertical dimension that provides the distances from the plane of the Milky Way, with the maps presented in the remaining two dimensions.

    UK Schmidt Telescope Exterior
    UK Schmidt Telescope Interior
    UK Schmidt Telescope, Siding Spring Observatory (SSO), New South Wales, Australia

    Wyse, who is on the executive board of the RAVE project, said the survey supplied the mapmakers with data related to 500,000 stars. The vast size of the sample enabled the mapmakers to determine the distances of the material that causes the DIBs and thus how the material is distributed throughout the Milky Way Galaxy. The resulting maps showed the intriguing result that the complex molecules thought to be responsible for the DIBs are distributed differently than another known component of the interstellar medium — the solid particles known as dust — also traced by the RAVE survey.

    Future studies can use the techniques outlined in the new paper to assemble other maps that should further solve the mysteries surrounding where DIBS are located and what materials cause them. “To figure out what something is, you first have to figure out where it is,” Wyse said, “and that’s what this paper does. Larger surveys will provide more details in the future. This paper has demonstrated how to do that.”

    Janez Kos and Tomaz Zwitter of the University of Ljubljana in Slovenia led the astronomy team that produced this paper. Wyse was the third author listed on the paper.

    A portion of the funds for this project came from U.S. National Science Foundation.

    See the full article here.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.

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  • richardmitnick 7:59 am on August 3, 2014 Permalink | Reply
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    From ScienceDaily: “Companion planets can increase old worlds’ chance at life” 

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    Science Daily

    August 1, 2014
    Peter Kelley, University of Washington

    Having a companion in old age is good for people — and, it turns out, might extend the chance for life on certain Earth-sized planets in the cosmos as well.

    planet

    Planets cool as they age. Over time their molten cores solidify and inner heat-generating activity dwindles, becoming less able to keep the world habitable by regulating carbon dioxide to prevent runaway heating or cooling.

    But astronomers at the University of Washington and the University of Arizona have found that for certain planets about the size of our own, the gravitational pull of an outer companion planet could generate enough heat — through a process called tidal heating — to effectively prevent that internal cooling, and extend the inner world’s chance at hosting life.

    UW astronomer Rory Barnes is second author of a paper published in the July issue of the Monthly Notices of the Royal Astronomical Society. The lead authors are graduate student Christa Van Laerhoven and planetary scientist Richard Greenberg at the University of Arizona.

    Tidal heating results from the gravitational push and pull of the outer companion planet on its closer-in neighbor, Barnes said. The effect happens locally, so to speak, on Jupiter’s moons Io and Europa. The researchers showed that this phenomenon can take place on exoplanets — those outside the solar system — as well.

    Using computer models, the researchers found the effect can occur on older Earth-sized planets in noncircular orbits in the habitable zone of low-mass stars, or those less than one-quarter the mass of the Sun. The habitable zone is that swath of space around a star just right to allow an orbiting rocky planet to sustain liquid water on its surface, thus giving life a chance.

    “When the planet is closer to the star, the gravitational field is stronger and the planet is deformed into an American football shape. When farther from the star, the field is weaker and the planet relaxes into a more spherical shape,” Barnes said. “This constant flexing causes layers inside the planet to rub against each other, producing frictional heating.”

    The outer planet is necessary, Barnes added, to keep the potentially habitable planet’s orbit noncircular. When a planet’s orbit is circular, the gravitational pull from its host star is constant, so its shape never changes, and there is no tidal heating.

    And so, the researchers conclude, any discoveries of Earth-sized planets in the habitable zone of old, small stars should be followed by searches for outer companion planets that might improve the inner world’s chance at hosting life.

    The combined effect of the ancient planet’s own tectonics and tidal heating generated by the outer companion, Barnes said, might allow such planets to host some of the longest-lived surface habitats in the universe.

    “Perhaps in the distant future, after our sun has died out, our descendants will live on worlds like these.”

    The research was done through the Virtual Planetary Laboratory, a UW-based interdisciplinary research group. The research was funded through the NASA Earth and Space Science Fellowship Program and the National Science Foundation.

    See the full article here.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.

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  • richardmitnick 2:42 pm on July 31, 2014 Permalink | Reply
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    From ScienceDaily: “Mercury’s bizzare magnetic field tells scientists how its interior is different from Earth’s” 

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    July 30, 2014
    No Writer Credit

    Earth and Mercury are both rocky planets with iron cores, but Mercury’s interior differs from Earth’s in a way that explains why the planet has such a bizarre magnetic field, UCLA planetary physicists and colleagues report.

    MERCURY

    Measurements from NASA’s Messenger spacecraft have revealed that Mercury’s magnetic field is approximately three times stronger at its northern hemisphere than its southern one. In the current research, scientists led by Hao Cao, a UCLA postdoctoral scholar working in the laboratory of Christopher T. Russell, created a model to show how the dynamics of Mercury’s core contribute to this unusual phenomenon.

    NASA Messenger satellite
    NASA Messenger satellite

    The magnetic fields that surround and shield many planets from the sun’s energy-charged particles differ widely in strength. While Earth’s is powerful, Jupiter’s is more than 12 times stronger, and Mercury has a rather weak magnetic field. Venus likely has none at all. The magnetic fields of Earth, Jupiter and Saturn show very little difference between the planets’ two hemispheres.

    Within Earth’s core, iron turns from a liquid to a solid at the inner boundary of the planet’s liquid outer core; this results in a solid inner part and liquid outer part. The solid inner core is growing, and this growth provides the energy that generates Earth’s magnetic field. Many assumed, incorrectly, that Mercury would be similar.

    “Hao’s breakthrough is in understanding how Mercury is different from the Earth so we could understand Mercury’s strongly hemispherical magnetic field,” said Russell, a co-author of the research and a professor in the UCLA College’s department of Earth, planetary and space sciences. “We had figured out how the Earth works, and Mercury is another terrestrial, rocky planet with an iron core, so we thought it would work the same way. But it’s not working the same way.”

    Mercury’s peculiar magnetic field provides evidence that iron turns from a liquid to a solid at the core’s outer boundary, say the scientists, whose research currently appears online in the journal Geophysical Research Letters and will be published in an upcoming print edition.

    “It’s like a snow storm in which the snow formed at the top of the cloud and middle of the cloud and the bottom of the cloud too,” said Russell. “Our study of Mercury’s magnetic field indicates iron is snowing throughout this fluid that is powering Mercury’s magnetic field.”

    The research implies that planets have multiple ways of generating a magnetic field.

    Hao and his colleagues conducted mathematical modeling of the processes that generate Mercury’s magnetic field. In creating the model, Hao considered many factors, including how fast Mercury rotates and the chemistry and complex motion of fluid inside the planet.

    The cores of both Mercury and Earth contain light elements such as sulfur, in addition to iron; the presence of these light elements keeps the cores from being completely solid and “powers the active magnetic field-generation processes,” Hao said.

    Hao’s model is consistent with data from Messenger and other research on Mercury and explains Mercury’s asymmetric magnetic field in its hemispheres. He said the first important step was to “abandon assumptions” that other scientists make.

    “Planets are different from one another,” said Hao, whose research is funded by a NASA fellowship. “They all have their individual character.”

    Co-authors include Jonathan Aurnou, professor of planetary science and geophysics in UCLA’s Department of Earth, Planetary and Space Sciences, and Johannes Wicht, a research scientist at Germany’s Max Planck Institute for Solar System Research.

     
  • richardmitnick 2:27 pm on July 31, 2014 Permalink | Reply
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    From Science Daily: “Weighing the Milky Way: Researchers devise precise method for calculating the mass of galaxies” 

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    Science Daily

    Does the Milky Way look fat in this picture? Has Andromeda been taking skinny selfies? It turns out the way some astrophysicists have been studying our galaxy made it appear that the Milky Way might be more massive than it’s neighbor down the street, Andromeda.

    andro
    The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda. The image also shows Messier Objects 32 and 110, as well as NGC 206 (a bright star cloud in the Andromeda Galaxy) and the star Nu Andromedae. This image was taken using a hydrogen-alpha filter.

    Not true, says a study published in the journal Monthly Notices of the Royal Astronomical Society by an international group of researchers, including Matthew Walker of Carnegie Mellon University‘s McWilliams Center for Cosmology. In the paper, they demonstrate a new, more accurate method for measuring the mass of galaxies. Using this method, the researchers have shown that the Milky Way has only about half the mass of its neighbor, the Andromeda Galaxy.

    In previous studies, researchers were only able to estimate the mass of the Milky Way and Andromeda based on observations made using their smaller satellite dwarf galaxies. In the new study, researchers culled previously published data that contained information about the distances between the Milky Way, Andromeda and other close-by galaxies — including those that weren’t satellites — that reside in and right outside an area referred to as the Local Group.

    lg
    Local Group which includes both Andromeda and the Milky Way

    Galaxies in the Local Group are bound together by their collective gravity. As a result, while most galaxies, including those on the outskirts of the Local Group, are moving farther apart due to expansion [dark energy?], the galaxies in the Local Group are moving closer together because of gravity. For the first time, researchers were able to combine the available information about gravity and expansion to complete precise calculations of the masses of both the Milky Way and Andromeda.

    “Historically, estimations of the Milky Way’s mass have been all over the map,” said Walker, an assistant professor of physics at Carnegie Mellon. “By studying two massive galaxies that are close to each other and the galaxies that surround them, we can take what we know about gravity and pair that with what we know about expansion to get an accurate account of the mass contained in each galaxy. This is the first time we’ve been able to measure these two things simultaneously.”

    By studying both the galaxies in and immediately outside the Local Group, Walker was able to pinpoint the group’s center. The researchers then calculated the mass of both the ordinary, visible matter and the invisible dark matter throughout both galaxies based on each galaxy’s present location within the Local Group. Andromeda had twice as much mass as the Milky Way, and in both galaxies 90 percent of the mass was made up of dark matter.

    The study was supported by the UK’s Science and Technology Facilities Council and led by Jorge Peñarrubia of the University of Edinburgh’s School of Physics and Astronomy. Co-authors include Yin-Zhe Ma of the University of British Columbia and Alan McConnachie of the NRC Herzberg Institute of Astrophysics.

    See the full article here.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.


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  • richardmitnick 1:03 pm on July 11, 2014 Permalink | Reply
    Tags: , , , , Dragonfly telescope array, ScienceDaily   

    From ScienceDaily: “Hi-ho! Astronomers discover seven dwarf galaxies with new telescope” 

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    ScienceDaily

    Date: July 10, 2014
    Source: Yale University. The original article was written by Jim Shelton

    Meet the seven new dwarf galaxies.

    Yale University astronomers, using a new type of telescope made by stitching together telephoto lenses, recently discovered seven celestial surprises while probing a nearby spiral galaxy. The previously unseen galaxies may yield important insights into dark matter and galaxy evolution, while possibly signaling the discovery of a new class of objects in space.

    For now, scientists know they have found a septuplet of new galaxies that were previously overlooked because of their diffuse nature: The ghostly galaxies emerged from the night sky as the team obtained the first observations from the “homemade” telescope.

    dg
    This image shows the field of view from the Dragonfly Telephoto Array, centered on M101. Inset images highlight the seven newly discovered galaxies.
    Credit: Image courtesy of Yale University

    The discovery came quickly, in a relatively small section of sky. “We got an exciting result in our first images,” said Allison Merritt, a Yale graduate student and lead author of a paper about the discovery in The Astrophysical Journal Letters. “It was very exciting. It speaks to the quality of the telescope.”

    Pieter van Dokkum, chair of Yale’s astronomy department, designed the robotic telescope with University of Toronto astronomer Roberto Abraham. Their Dragonfly Telephoto Array uses eight telephoto lenses with special coatings that suppress internally scattered light. This makes the telescope uniquely adept at detecting the very diffuse, low surface brightness of the newly discovered galaxies.

    “These are the same kind of lenses that are used in sporting events like the World Cup. We decided to point them upward instead,” van Dokkum said. He and Abraham built the compact, oven-sized telescope in 2012 at New Mexico Skies, an observatory in Mayhill, N.M. The telescope was named Dragonfly because the lenses resemble the compound eye of an insect.

    Dragonfly telescope Array
    Dragonfly Telescope Array

    “We knew there was a whole set of science questions that could be answered if we could see diffuse objects in the sky,” van Dokkum said. In addition to discovering new galaxies, the team is looking for debris from long-ago galaxy collisions.

    “It’s a new domain. We’re exploring a region of parameter space that had not been explored before,” van Dokkum said.

    The Yale scientists will tackle a key question next: Are these seven newly found objects dwarf galaxies orbiting around the M101 spiral galaxy, or are they located much closer or farther away, and just by chance are visible in the same direction as M101?

    If it’s the latter, Merritt said, these objects represent something entirely different. “There are predictions from galaxy formation theory about the need for a population of very diffuse, isolated galaxies in the universe,” Merritt said. “It may be that these seven galaxies are the tip of the iceberg, and there are thousands of them in the sky that we haven’t detected yet.”

    Merritt stressed that until they collect more data and determine the distances to the objects, researchers won’t know their true nature. But the possibilities are intriguing enough that the team has been granted the opportunity to use the Hubble Space Telescope for further study.

    “I’m confident that some of them will turn out to be a new class of objects,” van Dokkum said. “I’d be surprised if all seven of them are satellites of M101.”

    Meanwhile, there is also more work to be done with the new telescope. “We are collecting new data with the Dragonfly telescope every clear night. We’re all curious to see what other surprises the night sky has in store for us,” Merritt said.

    See the full article here.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.

     
  • richardmitnick 6:58 pm on December 10, 2012 Permalink | Reply
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    From ESA Herschel via ScienceDaily: “A Twisted Ring in the Galactic Centre” 

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    July 21, 2011 (Posted at Facebook 12.10.12)
    No writer credit

    Astronomers at the University of Hertfordshire are part of an international team which has observed unprecedented views of a ring in the centre of our Milky Way galaxy with the Herschel Space Observatory.

    Herschel 1
    Warmer gas and dust from the Centre of our Galaxy is shown in blue in the above image, while the colder material appears red. The ring, in yellow, is made of gas and dust at a temperature of just 15 degrees above absolute zero. The bright regions are denser, and include some of the most massive and active sites of star formation in our Galaxy (Credit: Image courtesy of University of Hertfordshire)

    The ribbon of gas and dust is more than 600 light years across and appears to be twisted, for reasons which have yet to be explained. The origin of the ring could provide insight into the history of the Milky WayThe new results are published in a recent issue of the Astrophysical Journal Letters.

    ‘Hints of this feature were seen in previous images of the Galactic Centre made from the ground, but no-one realised what it was,’ explained Dr Mark Thompson of the University of Hertfordshire. ‘It was not until the launch of Herschel, with its unparalleled wavelength coverage, that we could measure the temperature of the dust clouds and determine its true nature.”

    Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. Herschel is a flagship mission of the UK Space Agency, which funds the UK’s involvement in the UK-led SPIRE instrument. The SPIRE instrument was built, assembled and tested in the UK at The Rutherford Appleton Laboratory in Oxfordshire by an international consortium from Europe, US, Canada and China, with strong support from the Science and Technology Facilities Council. SPIRE was developed by a consortium of institutes led by Cardiff Univ. (UK). The images were obtained as part of the Herschel Key Project Hi-GAL, which is led by Sergio Molinari of the Institute of Space Physics in Rome and who is lead author of the new paper.

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.


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