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  • richardmitnick 1:28 pm on October 15, 2018 Permalink | Reply
    Tags: , , , , CI Tau, , Planet formation models, Protoplanetary discs, U Cambridge   

    From University of Cambridge: “Giant planets around young star raise questions about how planets form” 

    U Cambridge bloc

    From University of Cambridge

    15 Oct 2018
    Sarah Collins
    sarah.collins@admin.cam.ac.uk

    1
    Artist’s impression of CI Tau. Credit: Amanda Smith, Institute of Astronomy

    Researchers have identified a young star with four Jupiter and Saturn-sized planets in orbit around it, the first time that so many massive planets have been detected in such a young system. The system has also set a new record for the most extreme range of orbits yet observed: the outermost planet is more than a thousand times further from the star than the innermost one, which raises interesting questions about how such a system might have formed.

    The star is just two million years old – a ‘toddler’ in astronomical terms – and is surrounded by a huge disc of dust and ice. This disc, known as a protoplanetary disc, is where the planets, moons, asteroids and other astronomical objects in stellar systems form.

    The star was already known to be remarkable because it contains the first so-called hot Jupiter – a massive planet orbiting very close to its parent star – to have been discovered around such a young star. Although hot Jupiters were the first type of exoplanet to be discovered, their existence has long puzzled astronomers because they are often thought to be too close to their parent stars to have formed in situ.

    Now, a team of researchers led by the University of Cambridge have used the Atacama Large Millimeter/submillimeter Array (ALMA) to search for planetary ‘siblings’ to this infant hot Jupiter.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Their image revealed three distinct gaps in the disc, which, according to their theoretical modelling, were most likely caused by three additional gas giant planets also orbiting the young star. Their results are reported in The Astrophysical Journal Letters.

    The star, CI Tau, is located about 500 light years away in a highly-productive stellar ‘nursery’ region of the galaxy. Its four planets differ greatly in their orbits: the closest (the hot Jupiter) is within the equivalent of the orbit of Mercury, while the farthest orbits at a distance more than three times greater than that of Neptune. The two outer planets are about the mass of Saturn, while the two inner planets are respectively around one and 10 times the mass of Jupiter.

    The discovery raises many questions for astronomers. Around 1% of stars host hot Jupiters, but most of the known hot Jupiters are hundreds of times older than CI Tau. “It is currently impossible to say whether the extreme planetary architecture seen in CI Tau is common in hot Jupiter systems because the way that these sibling planets were detected – through their effect on the protoplanetary disc – would not work in older systems which no longer have a protoplanetary disc,” said Professor Cathie Clarke from Cambridge’s Institute of Astronomy, the study’s first author.

    According to the researchers, it is also unclear whether the sibling planets played a role in driving the innermost planet into its ultra-close orbit, and whether this is a mechanism that works in making hot Jupiters in general. And a further mystery is how the outer two planets formed at all.

    “Planet formation models tend to focus on being able to make the types of planets that have been observed already, so new discoveries don’t necessarily fit the models,” said Clarke. “Saturn mass planets are supposed to form by first accumulating a solid core and then pulling in a layer of gas on top, but these processes are supposed to be very slow at large distances from the star. Most models will struggle to make planets of this mass at this distance.”

    The task ahead will be to study this puzzling system at multiple wavelengths to get more clues about the properties of the disc and its planets. In the meantime, ALMA – the first telescope with the capability of imaging planets in the making – will likely throw out further surprises in other systems, re-shaping our picture of how planetary systems form.

    The research has been supported by the European Research Council.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

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  • richardmitnick 8:21 am on September 8, 2018 Permalink | Reply
    Tags: , , , , , , , Hydrogenase is an enzyme present in algae that is capable of reducing protons into hydrogen, Natural photosynthesis, Photosystem II, Scientists pioneer a new way to turn sunlight into fuel, Solar energy conversion, St. Johns College at Cambridge, U Cambridge   

    From University of Cambridge: “Scientists pioneer a new way to turn sunlight into fuel” 

    U Cambridge bloc

    From University of Cambridge

    03 Sep 2018
    No writer credit

    The quest to find new ways to harness solar power has taken a step forward after researchers successfully split water into hydrogen and oxygen by altering the photosynthetic machinery in plants.

    1
    Experimental two-electrode setup showing the photoelectrochemical cell illuminated with simulated solar light. Credit: Katarzyna Sokół

    Photosynthesis is the process plants use to convert sunlight into energy. Oxygen is produced as a by-product of photosynthesis when the water absorbed by plants is ‘split’. It is one of the most important reactions on the planet because it is the source of nearly all of the world’s oxygen. Hydrogen which is produced when the water is split could potentially be a green and unlimited source of renewable energy.

    A new study led by academics at the University of Cambridge, used semi-artificial photosynthesis to explore new ways to produce and store solar energy. They used natural sunlight to convert water into hydrogen and oxygen using a mixture of biological components and manmade technologies.

    The research could now be used to revolutionise the systems used for renewable energy production. A new paper, published in [Nature Energy], outlines how academics at the Reisner Laboratory in Cambridge’s Department of Chemistry developed their platform to achieve unassisted solar-driven water-splitting.

    Their method also managed to absorb more solar light than natural photosynthesis.

    Katarzyna Sokół, first author and PhD student at St John’s College, said: “Natural photosynthesis is not efficient because it has evolved merely to survive so it makes the bare minimum amount of energy needed – around 1-2 per cent of what it could potentially convert and store.”

    Artificial photosynthesis has been around for decades but it has not yet been successfully used to create renewable energy because it relies on the use of catalysts, which are often expensive and toxic. This means it can’t yet be used to scale up findings to an industrial level.

    The Cambridge research is part of the emerging field of semi-artificial photosynthesis which aims to overcome the limitations of fully artificial photosynthesis by using enzymes to create the desired reaction.

    Sokół and the team of researchers not only improved on the amount of energy produced and stored, they managed to reactivate a process in the algae that has been dormant for millennia.

    She explained: “Hydrogenase is an enzyme present in algae that is capable of reducing protons into hydrogen. During evolution, this process has been deactivated because it wasn’t necessary for survival but we successfully managed to bypass the inactivity to achieve the reaction we wanted – splitting water into hydrogen and oxygen.”

    Sokół hopes the findings will enable new innovative model systems for solar energy conversion to be developed.

    She added: “It’s exciting that we can selectively choose the processes we want, and achieve the reaction we want which is inaccessible in nature. This could be a great platform for developing solar technologies. The approach could be used to couple other reactions together to see what can be done, learn from these reactions and then build synthetic, more robust pieces of solar energy technology.”

    This model is the first to successfully use hydrogenase and photosystem II to create semi-artificial photosynthesis driven purely by solar power.

    Dr Erwin Reisner, Head of the Reisner Laboratory, a Fellow of St John’s College, University of Cambridge, and one of the paper’s authors described the research as a ‘milestone’.

    He explained: “This work overcomes many difficult challenges associated with the integration of biological and organic components into inorganic materials for the assembly of semi-artificial devices and opens up a toolbox for developing future systems for solar energy conversion.”

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 2:36 pm on August 5, 2018 Permalink | Reply
    Tags: , , , , , Scientists identify exoplanets where life could develop as it did on Earth, U Cambridge   

    From U Cambridge via Astrobiology Magazine: “Scientists identify exoplanets where life could develop as it did on Earth” 

    U Cambridge bloc

    From University of Cambridge

    Astrobiology Magazine

    From Astrobiology Magazine

    Aug 4, 2018
    1
    Artist’s concept depicting one possible appearance of the planet Kepler-452b. Credit: NASA Ames/JPL-Caltech/T. Pyle

    Scientists have identified a group of planets outside our solar system where the same chemical conditions that may have led to life on Earth exist.

    The researchers, from the University of Cambridge and the Medical Research Council Laboratory of Molecular Biology (MRC LMB), found that the chances for life to develop on the surface of a rocky planet like Earth are connected to the type and strength of light given off by its host star.

    Their study, published in the journal Science Advances, proposes that stars which give off sufficient ultraviolet (UV) light could kick-start life on their orbiting planets in the same way it likely developed on Earth, where the UV light powers a series of chemical reactions that produce the building blocks of life.

    The researchers have identified a range of planets where the UV light from their host star is sufficient to allow these chemical reactions to take place, and that lie within the habitable range where liquid water can exist on the planet’s surface.

    “This work allows us to narrow down the best places to search for life,” said Dr Paul Rimmer, a postdoctoral researcher with a joint affiliation at Cambridge’s Cavendish Laboratory and the MRC LMB, and the paper’s first author. “It brings us just a little bit closer to addressing the question of whether we are alone in the universe.”

    The new paper is the result of an ongoing collaboration between the Cavendish Laboratory and the MRC LMB, bringing together organic chemistry and exoplanet research. It builds on the work of Professor John Sutherland, a co-author on the current paper, who studies the chemical origin of life on Earth.

    In a paper published in 2015, Professor Sutherland’s group at the MRC LMB proposed that cyanide, although a deadly poison, was in fact a key ingredient in the primordial soup from which all life on Earth originated.

    In this hypothesis, carbon from meteorites that slammed into the young Earth interacted with nitrogen in the atmosphere to form hydrogen cyanide. The hydrogen cyanide rained to the surface, where it interacted with other elements in various ways, powered by the UV light from the sun. The chemicals produced from these interactions generated the building blocks of RNA, the close relative of DNA which most biologists believe was the first molecule of life to carry information.

    In the laboratory, Sutherland’s group recreated these chemical reactions under UV lamps, and generated the precursors to lipids, amino acids and nucleotides, all of which are essential components of living cells.

    “I came across these earlier experiments, and as an astronomer, my first question is always what kind of light are you using, which as chemists they hadn’t really thought about,” said Rimmer. “I started out measuring the number of photons emitted by their lamps, and then realised that comparing this light to the light of different stars was a straightforward next step.”

    The two groups performed a series of laboratory experiments to measure how quickly the building blocks of life can be formed from hydrogen cyanide and hydrogen sulphite ions in water when exposed to UV light. They then performed the same experiment in the absence of light.

    “There is chemistry that happens in the dark: it’s slower than the chemistry that happens in the light, but it’s there,” said senior author Professor Didier Queloz, also from the Cavendish Laboratory. “We wanted to see how much light it would take for the light chemistry to win out over the dark chemistry.”

    The same experiment run in the dark with the hydrogen cyanide and the hydrogen sulphite resulted in an inert compound which could not be used to form the building blocks of life, while the experiment performed under the lights did result in the necessary building blocks.

    The researchers then compared the light chemistry to the dark chemistry against the UV light of different stars. They plotted the amount of UV light available to planets in orbit around these stars to determine where the chemistry could be activated.

    They found that stars around the same temperature as our sun emitted enough light for the building blocks of life to have formed on the surfaces of their planets. Cool stars, on the other hand, do not produce enough light for these building blocks to be formed, except if they have frequent powerful solar flares to jolt the chemistry forward step by step. Planets that both receive enough light to activate the chemistry and could have liquid water on their surfaces reside in what the researchers have called the abiogenesis zone.

    2
    Diagram of confirmed exoplanets within the liquid water habitable zone (as well as Earth). Credit: Paul Rimmer

    Among the known exoplanets which reside in the abiogenesis zone are several planets detected by the Kepler telescope, including Kepler 452b, a planet that has been nicknamed Earth’s ‘cousin’, although it is too far away to probe with current technology. Next-generation telescopes, such as NASA’s TESS and James Webb Telescopes, will hopefully be able to identify and potentially characterise many more planets that lie within the abiogenesis zone.

    Of course, it is also possible that if there is life on other planets, that it has or will develop in a totally different way than it did on Earth.

    “I’m not sure how contingent life is, but given that we only have one example so far, it makes sense to look for places that are most like us,” said Rimmer. “There’s an important distinction between what is necessary and what is sufficient. The building blocks are necessary, but they may not be sufficient: it’s possible you could mix them for billions of years and nothing happens. But you want to at least look at the places where the necessary things exist.”

    According to recent estimates, there are as many as 700 million trillion terrestrial planets in the observable universe. “Getting some idea of what fraction have been, or might be, primed for life fascinates me,” said Sutherland. “Of course, being primed for life is not everything and we still don’t know how likely the origin of life is, even given favourable circumstances – if it’s really unlikely then we might be alone, but if not, we may have company.”

    The research was funded by the Kavli Foundation and the Simons Foundation.

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
    • stewarthoughblog 7:04 pm on August 5, 2018 Permalink | Reply

      Some very interesting science here, but very speculative to set a “abiogenesis zone” based on the paucity of habitable factors, even admitting this is the best possible at this time.

      Abiogenesis is a myth, like Darwin’s “warm little ponds,” Oparin-Haldane primordial soup, and Miller-Urey test tube goo. If there is no clue how naturalistically life developed on Earth, it is a matter of faith, not objective science, to believe it is relatively easily generated on the basis of the factors delineated here.

      Like

  • richardmitnick 11:55 am on July 4, 2018 Permalink | Reply
    Tags: , , , , The Gaia Sausage: the major collision that changed the Milky Way, U Cambridge   

    From University of Cambridge: “The Gaia Sausage: the major collision that changed the Milky Way” 

    U Cambridge bloc

    From University of Cambridge

    7.4.18

    1
    Artist’s impression of a collision between the Milky Way and a massive dwarf. Credit: V. Belokurov (Cambridge, UK) based on an image by ESO/Juan Carlos Muñoz

    An international team of astronomers has discovered an ancient and dramatic head-on collision between the Milky Way and a smaller object, dubbed ‘the Sausage galaxy’. The cosmic crash was a defining event in the early history of the Milky Way and reshaped the structure of our galaxy, fashioning both the galaxy’s inner bulge and its outer halo, the astronomers report in a series of new papers.

    The astronomers propose that around eight to 10 billion years ago, an unknown dwarf galaxy smashed into our own Milky Way. The dwarf did not survive the impact. It quickly fell apart, and the wreckage is now all around us.

    “The collision ripped the dwarf to shreds, leaving its stars moving on very radial orbits, like needles,” said Vasily Belokurov of the University of Cambridge and the Center for Computational Astrophysics at the Flatiron Institute in New York City. “These stars’ paths take them very close to the centre of our galaxy. This is a tell-tale sign that the dwarf galaxy came in on a really eccentric orbit and its fate was sealed.”

    The salient features of this extraordinary event are outlined in several new papers, some of which were led by Cambridge graduate student GyuChul Myeong. He and colleagues used data from the European Space Agency’s Gaia satellite. This spacecraft has been mapping the stellar content of our galaxy, recording the journeys of stars as they travel through the Milky Way. Thanks to Gaia, astronomers now know the positions and trajectories of our celestial neighbours with unprecedented accuracy.

    “The paths of the stars from the galactic merger earned the moniker ‘Gaia Sausage’,” said Wyn Evans of Cambridge’s Institute of Astronomy. “We plotted the velocities of the stars, and the sausage shape just jumped out at us. As the smaller galaxy broke up, its stars were thrown out on very radial orbits. These Sausage stars are what’s left of the last major merger of the Milky Way.”

    There are ongoing mergers taking place right now, such as between the puny Sagittarius dwarf galaxy and the Milky Way. However, the Sausage galaxy was much more massive. Its total mass in gas, stars and dark matter was more than 10 billion times the mass of our sun. When it crashed into the young Milky Way, it caused a lot of mayhem. The Sausage’s piercing trajectory meant that the Milky Way’s disk was probably puffed up or even fractured following the impact, and the Milky Way had to re-grow a new disk. At the same time, the Sausage debris was scattered all around the inner parts of the Milky Way, creating the ‘bulge’ at the galaxy’s centre and the surrounding ‘stellar halo’.

    “Numerical simulations of the galactic smash-up can reproduce these features,” said Denis Erkal of the University of Surrey. In simulations ran by Erkal and colleagues, stars from the Sausage galaxy enter stretched out orbits. The orbits are further elongated by the growing Milky Way disk, which swells and becomes thicker following the collision.

    “Evidence of this galactic remodelling is seen in the paths of stars inherited from the dwarf galaxy,” said Alis Deason of Durham University. “The Sausage stars are all turning around at about the same distance from the centre of the Galaxy. These U-turns cause the density in the Milky Way’s stellar halo to drop dramatically where the stars flip directions.” This discovery was especially pleasing for Deason, who predicted this orbital apocentric pile-up almost five years ago.

    The new research also identified at least eight large, spherical clumps of stars called globular clusters that were brought into the Milky Way by the Sausage galaxy. Small galaxies do not normally have globular clusters of their own, so the Sausage galaxy was big enough to host its own entourage of clusters.

    “While there have been many dwarf satellites falling onto the Milky Way over its life, this was the largest of them all,” said Sergey Koposov of Carnegie-Mellon University, who has been studying the kinematics of the Sausage stars and globular cluster in detail.

    The head-on collision of the Sausage galaxy was a defining event in the early history of the Milky Way. It created the thick disk and the inner stellar halo. Even though the merger took place at a very remote epoch, the stars in the Sausage galaxy can be picked out today. Memory of this event persists in the kinematics and chemistry of its stars. Thanks to the Gaia satellite, astronomers have miraculous data with which we can peer back into the very distant past and recreate the pre-history of our galactic home.

    Papers:
    Co-formation of the Galactic disc and the stellar halo MNRAS
    Apocenter Pile-Up: Origin of the Stellar Halo Density Break Accepted for publication in ApJ Letters
    The Sausage Globular Clusters ApJL, revised version
    The Milky Way Halo in Action Space The Astrophysical Journal
    The Shards of ω Centauri in press at MNRAS

    See the full article here .


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    Please help promote STEM in your local schools.

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 8:08 am on January 8, 2018 Permalink | Reply
    Tags: , , ‘Trophic support’, , The ‘metabolic vulnerability’ hypothesis, Transneuronal spread, Two abnormal proteins: amyloid beta and tau, U Cambridge   

    From U Cambridge: “Advances in brain imaging settle debate over spread of key protein in Alzheimer’s” 

    U Cambridge bloc

    University of Cambridge

    05 Jan 2018
    Craig Brierley
    Craig.Brierley@admin.cam.ac.uk

    Recent advances in brain imaging have enabled scientists to show for the first time that a key protein which causes nerve cell death spreads throughout the brain in Alzheimer’s disease – and hence that blocking its spread may prevent the disease from taking hold.

    1
    Alzheimer’s patients & carers. Credit: Global Panorama

    An estimated 44 million people worldwide are living with Alzheimer’s disease, a disease whose symptoms include memory problems, changes in behaviour and progressive loss of independence. These symptoms are caused by the build-up in the brain of two abnormal proteins: amyloid beta and tau. It is thought that amyloid beta occurs first, encouraging the appearance and spread of tau – and it is this latter protein that destroys the nerve cells, eating away at our memories and cognitive functions.

    Until a few years ago, it was only possible to look at the build-up of these proteins by examining the brains of Alzheimer’s patients who had died, post mortem. However, recent developments in positron emission tomography (PET) scanning have enabled scientists to begin imaging their build-up in patients who are still alive: a patient is injected with a radioactive ligand, a tracer molecule that binds to the target (tau) and can be detected using a PET scanner.

    In a study published today in the journal Brain, a team led by scientists at the University of Cambridge describe using a combination of imaging techniques to examine how patterns of tau relate to the wiring of the brain in 17 patients with Alzheimer’s disease, compared to controls.

    Quite how tau appears throughout the brain has been the subject of speculation among scientists. One hypothesis is that harmful tau starts in one place and then spreads to other regions, setting off a chain reaction. This idea – known as ‘transneuronal spread’ – is supported by studies in mice. When a mouse is injected with abnormal human tau, the protein spreads rapidly throughout the brain; however, this evidence is controversial as the amount of tau injected is much higher relative to brain size compared to levels of tau observed in human brains, and the protein spreads rapidly throughout a mouse’s brain whereas it spreads slowly throughout a human brain.

    There are also two other competing hypotheses. The ‘metabolic vulnerability’ hypothesis says that tau is made locally in nerve cells, but that some regions have higher metabolic demands and hence are more vulnerable to the protein. In these cases tau is a marker of distress in cells.

    The third hypothesis, ‘trophic support’, also suggests that some brain regions are more vulnerable than others, but that this is less to do with metabolic demand and more to do with a lack of nutrition to the region or with gene expression patterns.

    Thanks to the developments in PET scanning, it is now possible to compare these hypotheses.

    “Five years ago, this type of study would not have been possible, but thanks to recent advances in imaging, we can test which of these hypotheses best agrees with what we observe,” says Dr Thomas Cope from the Department of Clinical Neurosciences at the University of Cambridge, the study’s first author.

    Dr Cope and colleagues looked at the functional connections within the brains of the Alzheimer’s patients – in other words, how their brains were wired up – and compared this against levels of tau. Their findings supported the idea of transneuronal spread, that tau starts in one place and spreads, but were counter to predictions from the other two hypotheses.

    “If the idea of transneuronal spread is correct, then the areas of the brain that are most highly connected should have the largest build-up of tau and will pass it on to their connections. It’s the same as we might see in a flu epidemic, for example – the people with the largest networks are most likely to catch flu and then to pass it on to others. And this is exactly what we saw.”

    Professor James Rowe, senior author on the study, adds: “In Alzheimer’s disease, the most common brain region for tau to first appear is the entorhinal cortex area, which is next to the hippocampus, the ‘memory region’. This is why the earliest symptoms in Alzheimer’s tend to be memory problems. But our study suggests that tau then spreads across the brain, infecting and destroying nerve cells as it goes, causing the patient’s symptoms to get progressively worse.”

    Confirmation of the transneuronal spread hypothesis is important because it suggests that we might slow down or halt the progression of Alzheimer’s disease by developing drugs to stop tau from moving along neurons.

    3
    Image: Artist’s illustration of the spread of tau filaments (red) throughout the brain. Credit: Thomas Cope.

    The same team also looked at 17 patients affected by another form of dementia, known as progressive supranuclear palsy (PSP), a rare condition that affects balance, vision and speech, but not memory. In PSP patients, tau tends to be found at the base of the brain rather than throughout. The researchers found that the pattern of tau build-up in these patients supported the second two hypotheses, metabolic vulnerability and trophic support, but not the idea that tau spreads across the brain.

    The researchers also took patients at different stages of disease and looked at how tau build-up affected the connections in their brains.

    In Alzheimer’s patients, they showed that as tau builds up and damages networks, the connections become more random, possibly explaining the confusion and muddled memories typical of such patients.

    In PSP, the ‘highways’ that carry most information in healthy individuals receives the most damage, meaning that information needs to travel around the brain along a more indirect route. This may explain why, when asked a question, PSP patients may be slow to respond but will eventually arrive at the correct answer.

    The study was funded by the NIHR Cambridge Biomedical Research Centre, the PSP Association, Wellcome, the Medical Research Council, the Patrick Berthoud Charitable Trust and the Association of British Neurologists.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 11:18 am on December 25, 2017 Permalink | Reply
    Tags: , Counterfactual communication, , , , U Cambridge,   

    From U Cambridge via phys.org: “Researchers chart the ‘secret’ movement of quantum particles” 

    U Cambridge bloc

    University of Cambridge

    phys.org

    December 22, 2017

    1
    Credit: Robert Couse-Baker

    Researchers from the University of Cambridge have taken a peek into the secretive domain of quantum mechanics. In a theoretical paper published in the journal Physical Review A, they have shown that the way that particles interact with their environment can be used to track quantum particles when they’re not being observed, which had been thought to be impossible.

    One of the fundamental ideas of quantum theory is that quantum objects can exist both as a wave and as a particle, and that they don’t exist as one or the other until they are measured. This is the premise that Erwin Schrödinger was illustrating with his famous thought experiment involving a dead-or-maybe-not-dead cat in a box.

    “This premise, commonly referred to as the wave function, has been used more as a mathematical tool than a representation of actual quantum particles,” said David Arvidsson-Shukur, a Ph.D. student at Cambridge’s Cavendish Laboratory, and the paper’s first author. “That’s why we took on the challenge of creating a way to track the secret movements of quantum particles.”

    Any particle will always interact with its environment, ‘tagging’ it along the way. Arvidsson-Shukur, working with his co-authors Professor Crispin Barnes from the Cavendish Laboratory and Axel Gottfries, a Ph.D. student from the Faculty of Economics, outlined a way for scientists to map these ‘tagging’ interactions without looking at them. The technique would be useful to scientists who make measurements at the end of an experiment but want to follow the movements of particles during the full experiment.

    Some quantum scientists have suggested that information can be transmitted between two people – usually referred to as Alice and Bob – without any particles travelling between them. In a sense, Alice gets the message telepathically. This has been termed counterfactual communication because it goes against the accepted ‘fact’ that for information to be carried between sources, particles must move between them.

    “To measure this phenomenon of counterfactual communication, we need a way to pin down where the particles between Alice and Bob are when we’re not looking,” said Arvidsson-Shukur. “Our ‘tagging’ method can do just that. Additionally, we can verify old predictions of quantum mechanics, for example that particles can exist in different locations at the same time.”

    The founders of modern physics devised formulas to calculate the probabilities of different results from quantum experiments. However, they did not provide any explanations of what a quantum particle is doing when it’s not being observed. Earlier experiments have suggested that the particles might do non-classical things when not observed, like existing in two places at the same time. In their paper, the Cambridge researchers considered the fact that any particle travelling through space will interact with its surroundings. These interactions are what they call the ‘tagging’ of the particle. The interactions encode information in the particles that can then be decoded at the end of an experiment, when the particles are measured.

    The researchers found that this information encoded in the particles is directly related to the wave function that Schrödinger postulated a century ago. Previously the wave function was thought of as an abstract computational tool to predict the outcomes of quantum experiments. “Our result suggests that the wave function is closely related to the actual state of particles,” said Arvidsson-Shukur. “So, we have been able to explore the ‘forbidden domain’ of quantum mechanics: pinning down the path of quantum particles when no one is observing them.”

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 1:13 pm on December 20, 2017 Permalink | Reply
    Tags: , , , , , Habitable planets could exist around pulsars, , , The first exoplanets ever discovered were around the pulsar PSR B1257+12, U Cambridge   

    From U Cambridge: “Habitable planets could exist around pulsars” 

    U Cambridge bloc

    University of Cambridge

    19 Dec 2017
    Sarah Collins
    sarah.collins@admin.cam.ac.uk

    1
    It is theoretically possible that habitable planets exist around pulsars – spinning neutron stars that emit short, quick pulses of radiation. According to new research, such planets must have an enormous atmosphere that converts the deadly x-rays and high energy particles of the pulsar into heat. The results, from astronomers at the University of Cambridge and Leiden University, are reported in the journal Astronomy & Astrophysics.

    Pulsars are known for their extreme conditions. Each is a fast-spinning neutron star – the collapsed core of a massive star that has gone supernova at the end of its life. Only 10 to 30 kilometres across, a pulsar possesses enormous magnetic fields, accretes matter, and regularly gives out large bursts of X-rays and highly energetic particles.

    Surprisingly, despite this hostile environment, neutron stars are known to host exoplanets. The first exoplanets ever discovered were around the pulsar PSR B1257+12 – but whether these planets were originally in orbit around the precursor massive star and survived the supernova explosion, or formed in the system later remains an open question. Such planets would receive little visible light but would be continually blasted by the energetic radiation and stellar wind from the host. Could such planets ever host life?

    For the first time, astronomers have tried to calculate the ‘habitable’ zones near neutron stars – the range of orbits around a star where a planetary surface could possibly support water in a liquid form. Their calculations show that the habitable zone around a neutron star can be as large as the distance from our Earth to our Sun. An important premise is that the planet must be a super-Earth, with a mass between one and ten times our Earth. A smaller planet will lose its atmosphere within a few thousand years under the onslaught of the pulsar winds. To survive this barrage, a planet’s atmosphere must be a million times thicker than ours – the conditions on a pulsar planet surface might resemble those of the deep ocean floor on Earth.

    The astronomers studied the pulsar PSR B1257+12 about 2300 light-years away as a test case, using the X-ray Chandra space telescope.

    NASA/Chandra Telescope

    Of the three planets in orbit around the pulsar, two are super-Earths with a mass of four to five times our Earth, and orbit close enough to the pulsar to warm up. According to co-author Alessandro Patruno from Leiden University, “The temperature of the planets might be suitable for the presence of liquid water on their surface. Though, we don’t know yet if the two super-Earths have the right, extremely dense atmosphere.”

    In the future, Patruno and his co-author Mihkel Kama from Cambridge’s Institute of Astronomy would like to observe the pulsar in more detail and compare it with other pulsars. The European Southern Observatory’s ALMA Telescope would be able to show dust discs around neutron stars, which are good predictors of planets. The Milky Way contains about one billion neutron stars, of which about 200,000 are pulsars. So far, 3000 pulsars have been studied and only five pulsar planets have been found.

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 7:55 am on November 6, 2017 Permalink | Reply
    Tags: , First detailed chronological study of Leonardo’s work on friction, , , Study reveals Leonardo da Vinci’s “irrelevant” scribbles mark the spot where he first recorded the laws of friction, Tribology, U Cambridge   

    From University of Cambridge: “Study reveals Leonardo da Vinci’s “irrelevant” scribbles mark the spot where he first recorded the laws of friction” 

    U Cambridge bloc

    University of Cambridge

    21 Jul 2016 [Just found in social media]
    No writer credit found

    1
    Codex Forster III folio 72r. Credit: V&A Museum, London

    A new detailed study of notes and sketches by Leonardo da Vinci has identified a page of scribbles in a tiny notebook as the place where Leonardo first recorded the laws of friction. The research also shows that he went on to apply this knowledge repeatedly to mechanical problems for more than 20 years.

    Scribbled notes and sketches on a page in a notebook by Leonardo da Vinci, previously dismissed as irrelevant by an art historian, have been identified as the place where he first recorded his understanding of the laws of friction.

    The research by Professor Ian Hutchings, Professor of Manufacturing Engineering at the University of Cambridge and a Fellow of St John’s College, is the first detailed chronological study of Leonardo’s work on friction, and has also shown how he continued to apply his knowledge of the subject to wider work on machines over the next two decades.

    It is widely known that Leonardo conducted the first systematic study of friction, which underpins the modern science of “tribology”, but exactly when and how he developed these ideas has been uncertain until now.

    Professor Hutchings has discovered that Leonardo’s first statement of the laws of friction is in a tiny notebook measuring just 92 mm x 63 mm. The book, which dates from 1493 and is now held in the Victoria and Albert Museum in London, contains a statement scribbled quickly in Leonardo’s characteristic “mirror writing” from right to left.

    Ironically the page had already attracted interest because it also carries a sketch of an old woman in black pencil with a line below reading “cosa bella mortal passa e non dura”, which can be translated as “mortal beauty passes and does not last”. Amid debate surrounding the significance of the quote and speculation that the sketch could represent an aged Helen of Troy, the Director of the V & A in the 1920s referred to the jottings below as “irrelevant notes and diagrams in red chalk”.

    Professor Hutchings’s study has, however, revealed that the script and diagrams in red are of great interest to the history of tribology, marking a pivotal moment in Leonardo’s work on the subject.

    The rough geometrical figures underneath Leonardo’s red notes show rows of blocks being pulled by a weight hanging over a pulley – in exactly the same kind of experiment students might do today to demonstrate the laws of friction.

    Professor Hutchings said: “The sketches and text show Leonardo understood the fundamentals of friction in 1493. He knew that the force of friction acting between two sliding surfaces is proportional to the load pressing the surfaces together and that friction is independent of the apparent area of contact between the two surfaces. These are the ‘laws of friction’ that we nowadays usually credit to a French scientist, Guillaume Amontons, working two hundred years later.”

    “Leonardo’s 20-year study of friction, which incorporated his empirical understanding into models for several mechanical systems, confirms his position as a remarkable and inspirational pioneer of tribology.”

    Professor Hutchings’s research traces a clear path of development in Leonardo’s studies of friction and demonstrates that he realised that friction, while sometimes useful and even essential, also played a key role in limiting the efficiency of machines.

    Sketches of machine elements and mechanisms are pervasive in Leonardo’s notebooks and he used his remarkably sophisticated understanding of friction to analyse the behaviour of wheels and axles, screw threads and pulleys, all important components of the complicated machines he sketched.

    He wanted to understand the rules that governed the operation of these machines and knew that friction was important in limiting their efficiency and precision, grasping, for example, that resistance to the rotation of a wheel arose from friction at the axle bearing and calculating its effect.

    “Leonardo’s sketches and notes were undoubtedly based on experiments, probably with lubricated contacts,” added Hutchings. “He appreciated that friction depends on the nature of surfaces and the state of lubrication and his use and understanding of the ratios between frictional force and weight was much more nuanced than many have suggested.”

    Although he undoubtedly discovered the laws of friction, Leonardo’s work had no influence on the development of the subject over the following centuries and it was certainly unknown to Amontons.

    “Leonardo da Vinci’s studies of friction” by Professor Ian Hutchings is published in the journal Wear. The paper can be accessed in full via: http://www.sciencedirect.com/science/article/pii/S0043164816300588

    or http://www.ifm.eng.cam.ac.uk/uploads/Hutchings_Leonardo_Friction_2016_v2.pdf

    A general article on tribology that discusses its importance in modern engineering can be found at:

    http://www.ingenia.org.uk/Content/ingenia/issues/issue66/hutchings.pdf

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 7:44 pm on August 24, 2017 Permalink | Reply
    Tags: , , , , Kavli Institute for Cosmology, , , U Cambridge   

    From Kavli Institute for Cosmology, U Cambridge: “Ripples in Cosmic Web Measured Using Rare Double Quasars” 

    KavliFoundation

    The Kavli Foundation

    Kavli Institute for Cosmology, Cambridge

    Apr 28, 2017 [Where has this been?]

    1
    Volume rendering of the output from a supercomputer simulation showing part of the cosmic web, 11.5 billion years ago.

    The most barren regions of the Universe are the far-flung corners of intergalactic space. In these vast expanses between the galaxies there are only a few atoms per cubic meter – a diffuse haze of hydrogen gas left over from the Big Bang. Viewed on the largest scales, this diffuse material nevertheless accounts for the majority of atoms in the Universe, and fills the cosmic web, its tangled strands spanning billions of light years.

    Now a team of astronomers including Alberto Rorai and Girish Kulkarni, post-doctoral researchers at the Kavli Institute for Cosmology, University of Cambridge, have made the first measurements of small scale ripples in this primeval hydrogen gas. Although the regions of cosmic web they studied lie nearly 11 billion light years away, they were able to measure variations in its structure on scales a hundred thousand times smaller, comparable to the size of a single galaxy. Their results appear in the journal Science.

    2
    Schematic representation of the technique used to probe the small-scale structure of the cosmic web using light from a rare quasar pair. The spectra (bottom right) contain information about the hydrogen gas the light has encountered, as well as the distance of that gas. Image: Springel et al. (2005) (cosmic web) / J. Neidel, MPIA

    Intergalactic gas is so tenuous that it emits no light of its own. Instead astronomers study it indirectly by observing how it selectively absorbs the light coming from faraway sources known as quasars. Quasars constitute a brief hyper luminous phase of the galactic life-cycle, powered by the infall of matter onto a galaxy’s central supermassive black hole. Quasars act like cosmic lighthouses – bright, distant beacons that allow astronomers to study intergalactic atoms residing between the quasars location and Earth. But because these hyper luminous episodes last only a tiny fraction of a galaxy’s lifetime, quasars are correspondingly rare on the sky, and are typically separated by hundreds of millions of light years from each other.

    In order to probe the cosmic web on much smaller length scales, the astronomers exploited a fortuitous cosmic coincidence: they identified exceedingly rare pairs of quasars, right next to each other on the sky, and measured subtle differences in the absorption of intergalactic atoms measured along the two sightlines.

    Rorai, lead author of the study, says “One of the biggest challenges was developing the mathematical and statistical tools to quantify the tiny differences we measure in this new kind of data”. Rorai developed these tools as part of the research for his doctoral degree, and applied his tools to spectra of quasars obtained with the largest telescopes in the world, including the 10m diameter Keck telescopes at the summit of Mauna Kea in Hawaii, as well as ESO’s 8m diameter Very Large Telescope on Cerro Paranal, and the 6.5m diameter Magellan telescope at Las Campanas Observatory, both located in the Chilean Atacama Desert.

    The astronomers compared their measurements to supercomputer models that simulate the formation of cosmic structures from the Big Bang to the present. “The input to our simulations are the laws of Physics and the output is an artificial Universe which can be directly compared to astronomical data. I was delighted to see that these new measurements agree with the well-established paradigm for how cosmic structures form.” says Jose Oñorbe, a post-doctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, who led the supercomputer simulation effort. On a single laptop, these complex calculations would have required almost a thousand years to complete, but modern supercomputers enabled the researchers to carry them out in just a few weeks.

    Joseph Hennawi, professor of physics at UC Santa Barbara who led the search for these rare quasar pairs, explains “One reason why these small-scale fluctuations are so interesting is that they encode information about the temperature of gas in the cosmic web just a few billion years after the Big Bang.” Astronomers believe that the matter in the Universe went through phase transitions billions of years ago, which dramatically changed its temperature. These phase transitions, known as cosmic reionization, occurred when the collective ultraviolet glow of all stars and quasars in the Universe became intense enough to strip electrons off of the atoms in intergalactic space. How and when reionization occurred is one of the biggest open questions in the field of cosmology, and these new measurements provide important clues that will help narrate this chapter of cosmic history.

    3
    Spectra of both members of a close quasar pair used in the study. The subtle differences in the absorption features between the two sightlines allow the researchers to probe the small-scale structure of the cosmic web. Image: Rorai et al. / MPIA

    See the full article here .
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    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 10:03 am on July 12, 2017 Permalink | Reply
    Tags: , , , , Smallest-ever star discovered by astronomers EBLM J0555-57Ab, U Cambridge   

    From U Cambridge: “Smallest-ever star discovered by astronomers” 

    U Cambridge bloc

    Cambridge University

    12 Jul 2017
    Sarah Collins
    sarah.collins@admin.cam.ac.uk

    1
    A star about the size of Saturn – the smallest ever measured – has been identified by astronomers. No image credit.

    The smallest star yet measured has been discovered by a team of astronomers led by the University of Cambridge. With a size just a sliver larger than that of Saturn, the gravitational pull at its stellar surface is about 300 times stronger than what humans feel on Earth.

    The star is likely as small as stars can possibly become, as it has just enough mass to enable the fusion of hydrogen nuclei into helium. If it were any smaller, the pressure at the centre of the star would no longer be sufficient to enable this process to take place. Hydrogen fusion is also what powers the Sun, and scientists are attempting to replicate it as a powerful energy source here on Earth.

    These very small and dim stars are also the best possible candidates for detecting Earth-sized planets which can have liquid water on their surfaces, such as TRAPPIST-1, an ultracool dwarf surrounded by seven temperate Earth-sized worlds.

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile interior

    ESO Belgian robotic Trappist-South National Telescope at Cerro La Silla, Chile

    The newly-measured star, called EBLM J0555-57Ab, is located about six hundred light years away. It is part of a binary system, and was identified as it passed in front of its much larger companion, a method which is usually used to detect planets, not stars. Details will be published in the journal Astronomy & Astrophysics.

    “Our discovery reveals how small stars can be,” said Alexander Boetticher, the lead author of the study, and a Master’s student at Cambridge’s Cavendish Laboratory and Institute of Astronomy. “Had this star formed with only a slightly lower mass, the fusion reaction of hydrogen in its core could not be sustained, and the star would instead have transformed into a brown dwarf.”

    EBLM J0555-57Ab was identified by WASP, a planet-finding experiment run by the Universities of Keele, Warwick, Leicester and St Andrews.

    SuperWASP telescope, located on the island of La Palma amongst the Isaac Newton Group of telescopes (ING)

    EBLM J0555-57Ab was detected when it passed in front of, or transited, its larger parent star, forming what is called an eclipsing stellar binary system.

    Planet transit. NASA/Ames

    The parent star became dimmer in a periodic fashion, the signature of an orbiting object. Thanks to this special configuration, researchers can accurately measure the mass and size of any orbiting companions, in this case a small star. The mass of EBLM J0555-57Ab was established via the Doppler, wobble method, using data from the CORALIE spectrograph.

    ESO Swiss 1.2 meter Leonhard Euler Telescope at La Silla, using the CORALIE spectrograph

    “This star is smaller, and likely colder than many of the gas giant exoplanets that have so far been identified,” said von Boetticher. “While a fascinating feature of stellar physics, it is often harder to measure the size of such dim low-mass stars than for many of the larger planets. Thankfully, we can find these small stars with planet-hunting equipment, when they orbit a larger host star in a binary system. It might sound incredible, but finding a star can at times be harder than finding a planet.”

    This newly-measured star has a mass comparable to the current estimate for TRAPPIST-1, but has a radius that is nearly 30% smaller. “The smallest stars provide optimal conditions for the discovery of Earth-like planets, and for the remote exploration of their atmospheres,” said co-author Amaury Triaud, senior researcher at Cambridge’s Institute of Astronomy. “However, before we can study planets, we absolutely need to understand their star; this is fundamental.”

    Although they are the most numerous stars in the Universe, stars with sizes and masses less than 20% that of the Sun are poorly understood, since they are difficult to detect due to their small size and low brightness. The EBLM project, which identified the star in this study, aims to plug that lapse in knowledge. “Thanks to the EBLM project, we will achieve a far greater understanding of the planets orbiting the most common stars that exist, planets like those orbiting TRAPPIST-1,” said co-author Professor Didier Queloz of Cambridge’ Cavendish Laboratory.

    See the full article here .

    Please help promote STEM in your local schools.

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
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