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  • richardmitnick 7:21 am on August 21, 2018 Permalink | Reply
    Tags: Astronomy, , , , , First Stars Formed No Later Than 250 Million Years After The Big Bang With Direct Proof   

    From Ethan Siegel: “First Stars Formed No Later Than 250 Million Years After The Big Bang, With Direct Proof” 

    From Ethan Siegel
    Aug 20, 2018

    1
    In the big image at left, the many galaxies of a massive cluster called MACS J1149+2223 dominate the scene. Gravitational lensing by the giant cluster brightened the light from the newfound galaxy, known as MACS 1149-JD, some 15 times. At upper right, a partial zoom-in shows MACS 1149-JD in more detail, and a deeper zoom appears to the lower right. This is correct and consistent with General Relativity, and independent of how we visualize (or whether we visualize) space. (NASA/ESA/STSCI/JHU)

    The Universe is an enormous place, but we can’t see all the way back to the beginning. Here’s the latest record-breaker.

    No matter how far back we look in the Universe, we cannot yet observe the first stars or galaxies directly.

    2
    The absorption lines at a variety of redshifts show that the fundamental physics and sizes of atoms have not changed throughout the Universe, even as the light has redshifted due to its expansion. Unfortunately, the most light-blocking material exists at the earliest times, making finding the most distant galaxies an incredible challenge. (NASA, ESA, AND AND A. FEILD (STSCI))

    NASA/ESA Hubble Telescope

    The light they produce is too redshifted and blocked by too much intervening gas to be seen even by Hubble.

    3
    The most distant galaxy ever discovered in the known Universe, GN-z11, has its light come to us from 13.4 billion years ago: when the Universe was only 3% its current age: 407 million years old. But there are even more distant galaxies out there, and we at last have direct evidence for it. (NASA, ESA, AND G. BACON (STSCI))

    The most distant galaxy ever discovered is already late, dating back to 407 million years after the Big Bang.

    4
    Only because this distant galaxy, GN-z11, is located in a region where the intergalactic medium is mostly reionized, can Hubble reveal it to us at the present time. To see further, we require a better observatory, optimized for these kinds of detection, than Hubble. (NASA, ESA, AND A. FEILD (STSCI))

    But the very first stars should go back hundreds of million years further.

    5
    Various long-exposure campaigns, like the Hubble eXtreme Deep Field (XDF) shown here, have revealed thousands of galaxies in a volume of the Universe that represents a fraction of a millionth of the sky. But even with all the power of Hubble, and all the magnification of gravitational lensing, there are still galaxies out there beyond what we are capable of seeing. (NASA, ESA, H. TEPLITZ AND M. RAFELSKI (IPAC/CALTECH), A. KOEKEMOER (STSCI), R. WINDHORST (ARIZONA STATE UNIVERSITY), AND Z. LEVAY (STSCI))

    Gravitational Lensing NASA/ESA

    Sometime between the Cosmic Microwave Background [CMB], at 380,000 years, and that first galaxy, the first stars must have formed.

    Cosmic Background Radiation per ESA/Planck


    ESA/Planck 2009 to 2013

    6
    Schematic diagram of the Universe’s history, highlighting reionization. Before stars or galaxies formed, the Universe was full of light-blocking, neutral atoms. While most of the Universe doesn’t become reionized until 550 million years afterwards, a few fortunate regions are mostly reionized at much earlier times. (S. G. DJORGOVSKI ET AL., CALTECH DIGITAL MEDIA CENTER)

    Owing to the second-most-distant galaxy ever found, MACS1149-JD1, we can understand when.

    7
    The distant galaxy MACS1149-JD1 is gravitationally lensed by a foreground cluster, allowing it to be imaged at high resolution and in multiple instruments, even without next-generation technology.(ALMA (ESO/NAOJ/NRAO), NASA/ESA HUBBLE SPACE TELESCOPE, W. ZHENG (JHU), M. POSTMAN (STSCI), THE CLASH TEAM, HASHIMOTO ET AL.)

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

    We see MACS1149-JD1 as it was 530 million years after the Big Bang, while inside, it has a special signature: oxygen.

    8
    Supernova remnants (L) and planetary nebulae (R) are both ways for stars to recycle their burned, heavy elements back into the interstellar medium and the next generation of stars and planets. The truly first, pristine stars need to have been created before supernovae, planetary nebulae, or neutron star mergers polluted the interstellar medium with heavy elements. The detection of oxygen in this ultra-distant galaxy, along with the galaxy’s brightness, tells us it is already approximately 280 million years since the first stars formed within it.(ESO / VERY LARGE TELESCOPE / FORS INSTRUMENT & TEAM (L); NASA, ESA, C.R. O’DELL (VANDERBILT), AND D. THOMPSON (LARGE BINOCULAR TELESCOPE) (R))

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo


    ESO/FORS1 on the VLT


    U Arizona Large Binocular Telescope, Large Binocular Telescope Interferometer, or LBTI, is a ground-based instrument connecting two 8-meter class telescopes on Mount Graham, Arizona, USA, Altitude 3,221 m (10,568 ft.) to form the largest single-mount telescope in the world. The interferometer is designed to detect and study stars and planets outside our solar system. Image credit: NASA/JPL-Caltech.

    Oxygen is only produced by previous generations of stars, indicating that this galaxy is already old.

    9
    The first stars and galaxies in the Universe will be surrounded by neutral atoms of (mostly) hydrogen gas, which absorbs the starlight. We cannot yet observe this first starlight directly, but we can observe what happens after a bit of cosmic evolution, allowing us to infer when stars must have formed in great abundance. The first stars are made of hydrogen and helium alone, but produce copious amounts of oxygen, which show up in later generations of stars. (NICOLE RAGER FULLER / NATIONAL SCIENCE FOUNDATION)

    MACS1149-JD1 was imaged with microwave (ALMA), infrared (Spitzer), and optical (Hubble) data combined.

    NASA/Spitzer Infrared Telescope

    The results indicate that stars existed nearly 300 million years before our observations.

    10
    Our entire cosmic history is theoretically well-understood, but only qualitatively. It’s by observationally confirming and revealing various stages in our Universe’s past that must have occurred, like when the first stars and galaxies formed, that we can truly come to understand our cosmos. The Big Bang sets a fundamental limit to how far back we can see in any direction. (NICOLE RAGER FULLER / NATIONAL SCIENCE FOUNDATION)

    11
    As we’re exploring more and more of the Universe, we’re able to look farther away in space, which equates to farther back in time. The James Webb Space Telescope will take us to depths, directly, that our present-day observing facilities cannot match. (NASA / JWST AND HST TEAMS)

    NASA/ESA/CSA Webb Telescope annotated

    2021’s James Webb Space Telescope will image them firsthand.

    See the full article here .


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    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

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  • richardmitnick 10:39 pm on August 20, 2018 Permalink | Reply
    Tags: Ali Observatory on the Tibetan Plateau over 5100 metres above sea level, Astronomy, , , , Possible site for new 12 metre optical telescope, SODAR testing with Fulcrum 3D’s sonar radar,   

    From University of New South Wales: ” In search of the best telescope location, UNSW astronomer and alumnus head to high places” 

    U NSW bloc

    From University of New South Wales

    21 Aug 2018
    Ivy Shih

    An international effort to pinpoint the site for a new telescope is relying on technology developed by a UNSW alumnus during his PhD.

    1
    Dr Colin Bonner (left) and Professor Michael Ashley on location at Ali Observatory. Photo: Colin Bonner

    It is a tale of North and South with an astronomical twist, with a UNSW astronomer and a UNSW PhD alumnus heading from Antarctica to the Tibetan Plateau to help find the best site for a new, 12-metre optical telescope.

    This year, Professor Michael Ashley from the School of Physics and alumnus Dr Colin Bonner travelled to Ali Observatory in western Tibet to lead the testing and installation of SODAR (Sound Detection and Ranging), a device the astronomers will use to decide where a new telescope is best located.

    Ali Observatory on the Tibetan Plateau over 5100 metres above sea level

    The road to Tibet was a journey from one extreme to another. Before Tibet, Professor Ashley and Dr Bonner had been on scientific expeditions deploying telescopes in some of the most remote locations of Antartica, including the South Pole itself at latitude 90S. To reach Ali Observatory, the pair had to travel from Tibet’s capital Lhasa to Nagari Gunsa airport, the fourth highest altitude airport in the world.

    Ali Observatory is situated on the Tibetan Plateau, at more than 5100 metres above sea level. It’s a good location for studying the night sky, due to the combination of its high altitude and predominantly dry seasonal conditions in the region.

    “In astronomy you want to be as high as you can be because it gets you above some of the atmosphere, where it is nice and cold and there is not much water vapour,” says Professor Ashley.

    “It’s an amazing location. Antarctica is amazing in more ways than one, but the Tibetan Plateau is like the surface of the moon, albeit with some tufts of hardy grass and a few yaks.”

    The pair limited their time at Ali Observatory to a few hours at a time, however, to reduce the risk of altitude sickness.

    “The photos don’t capture the feeling of being there – you really notice the difficulty of breathing,” says Professor Ashley.

    Ashley and Bonner travelled to Tibet to install a SODAR to help evaluate the stability of the atmosphere at the location.

    2
    Fulcrum 3D’s sonar radar (cone-shaped object in the centre) installed onsite at Ali Observatory. Photo: Colin Bonner

    Atmosphere stability is critical for astronomers: tens of metres difference between where a telescope is placed can make the difference between a blurry image of a star and a clear high-resolution one.

    Original versions of the SODAR were put through their paces in Antarctica, where Professor Ashley and Dr Bonner previously worked at an international observatory.

    Chinese astronomer collaborators onsite in Antarctica saw the SODAR’s effectiveness and called on the combined expertise of Professor Ashley and Dr Bonner to apply it at Ali Observatory.

    There are now plans to construct a 12-metre optical telescope in Tibet. This will be the latest addition to an international cluster of smaller telescopes from the United States and Japan.

    “A big part of the visit was assessing locations – there is no point in having a Ferrari-style telescope put on a site that would not produce optimal conditions for astronomers,” says Dr Bonner.

    “If you are going to put in money to build a telescope, you need to be absolutely sure it is the best location.”

    The device will remain at Ali Observatory for at least a couple of years to collect seasonal atmospheric data. The information will then be analysed by Fulcrum3D and astronomers at the National Astronomical Observatory of China and UNSW to determine the best location for the new telescope.

    See the full article here .


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    U NSW Campus

    Welcome to UNSW Australia (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

     
  • richardmitnick 5:17 pm on August 20, 2018 Permalink | Reply
    Tags: Astronomy, , , , , , , , , , The scientific theories battling to explain the universe   

    From CNN: “The scientific theories battling to explain the universe” 

    1
    From CNN

    August 17, 2018
    1
    FNAL’s Don Lincoln

    In human history, there have been many interesting and epic feuds — the Hatfields and McCoys, Bette Davis and Joan Crawford, or the Notorious B.I.G and Tupac. Many of us love to read in tabloids or history books about the salacious details of how the bad blood came to be.

    Just like these human characters, scientific theories can also fall into disagreement, causing just as much drama in the science world.

    Recently, a group of scientists claimed to have found a fatal tension between two of the scientific community’s most mind-blowing theories: superstrings and dark energy. If the authors are correct, one of the two theories is in trouble.

    Superstring theory is a candidate theory of everything, with the operative word being “candidate,” meaning it is not yet accepted by the scientific community. It tries to explain all observed phenomena of the universe with a single principle. At its core, it predicts that the smallest building blocks of the cosmos aren’t the familiar atoms and protons, neutrons, and electrons; nor are the smallest building blocks the even-smaller quarks and lepton that my colleagues and I have discovered. Instead, superstring theory suggests that the very smallest building blocks of all are tiny and vibrating “strings.”

    These strings can vibrate in different ways — essentially different notes — with each note looking like one of the known subatomic particles. Waxing slightly poetic, superstring theory explains the universe as a vast and cosmic symphony.

    The other popular theory, called dark energy, is quite different. Astronomers have long known that the universe is expanding. For decades, we thought we understood that, because gravity is an attractive force, this expansion would slow over the lifetime of the universe. It was therefore a surprise when, in 1998, astronomers discovered that not only was the expansion of the universe not slowing down — it was speeding up.

    To explain this observation, astronomers added a type of energy — called dark energy — to Einstein’s equations describing the behavior of gravity. Dark energy is an energy field that permeates the entire universe. And, because the expansion of the universe is accelerating, dark energy must exist and it must be positive. The reason we know that is simple. If the dark energy didn’t exist or was negative, the expansion of the universe would be slowing down.

    So, what is it about these two theories that has caused such a conflict?

    In a nutshell, it’s hard to make a superstring theory with positive energy and yet the accelerating expansion of the universe demands it. If one theory is completely accurate it means that a key aspect of the other is wrong. And, on the face of it, things look bad for superstring theory. This is because while dark energy is still a theory, the accelerating expansion of the universe is not. Thus, dark energy is probably true, while superstring theory still remains only a conjecture.

    But there’s a reason that scientists aren’t rushing to media platforms to spread the news that superstring theory has been disproved.

    It’s because superstring theory is fiendishly complex. Aside from the prediction of subatomic vibrating strings, it also predicts that there are more dimensions of space than our familiar three. In fact, the theory predicts that there are nine in total — 10 if you include time. You’d think that this would be a fatal flaw of the theory, but these additional dimensions are thought to be invisibly small.

    Since these extra dimensions (if they exist) are smaller than our best instrumentation can detect, we don’t know what their shapes are, and scientists must consider all possibilities. But there are a lot of possibilities. In fact, there are more configurations than there are atoms in a million universes just like ours. It’s a crazy big number.

    So, what conclusion can we draw?

    With so many possible configurations, it would seem that superstring theory could predict just about anything, yet the scientists who pointed out the theories’ disagreement are making the bold claim that none of these configurations result in the existence of a positive and constant energy (aka, the theory of dark energy).

    And all the data recorded so far have made scientists feel relatively confident that dark energy not only exists, but is also both positive and nearly constant, making it seem likely that, if only one of these theories can be true, it’s dark energy for the win. Still, it’s premature to make any conclusions about the superstrings. It’s possible that scientists are not right about the nature of dark energy and they are using powerful instruments like the Dark Energy Survey to refine their measurements.

    The bottom line is that physicists are going to have to take this new idea seriously. It’s not quite a WWE cage match, but it’s going to be fun to watch these theories fight it out.

    See the full article here .

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  • richardmitnick 4:53 pm on August 20, 2018 Permalink | Reply
    Tags: Astronomy, , , , , Milky Way galactic disc, Star density map   

    From European Space Agency: “Star density map released” 

    ESA Space For Europe Banner

    From European Space Agency

    1
    Star density map
    Released 20/08/2018
    Copyright Galaxy Map / K. Jardine

    20/08/2018

    The second data release of ESA’s Gaia mission, made in April, has marked a turning point in the study of our Galactic home, the Milky Way.

    ESA/GAIA satellite

    Milky Way Galaxy Credits: NASA/JPL-Caltech/R. Hurt

    With an unprecedented catalogue of 3D positions and 2D motions of more than a billion stars, plus additional information on smaller subsets of stars and other celestial sources, Gaia has provided astronomers with an astonishing resource to explore the distribution and composition of the Galaxy and to investigate its past and future evolution.

    The majority of stars in the Milky Way are located in the Galactic disc, which has a flattened shape characterised by a pattern of spiral arms similar to that observed in spiral galaxies beyond our own. However, it is particularly challenging to reconstruct the distribution of stars in the disc, and especially the design of the Milky Way’s arms, because of our position within the disc itself.

    This is where Gaia’s measurements can make the difference.

    This image shows a 3D map obtained by focusing on one particular type of object: OB stars, the hottest, brightest and most massive stars in our Galaxy. Because these stars have relatively short lives – up to a few tens of million years – they are mostly found close to their formation sites in the Galactic disc. As such, they can be used to trace the overall distribution of young stars, star formation sites, and the Galaxy’s spiral arms.

    The map, based on 400 000 of this type of star within less than 10 000 light-years from the Sun, was created by Kevin Jardine, a software developer and amateur astronomer with an interest in mapping the Milky Way using a variety of astronomical data.

    It is centred on the Sun and shows the Galactic disc as if we were looking at it face-on from a vantage point outside the Galaxy.

    To deal with the massive number of stars in the Gaia catalogue, Kevin made use of so-called density isosurfaces, a technique that is routinely used in many practical applications, for example to visualise the tissue of organs of bones in CT scans of the human body. In this technique, the 3D distribution of individual points is represented in terms of one or more smooth surfaces that delimit regions with a different density of points.

    Here, regions of the Galactic disc are shown with different colours depending on the density of ionising stars recorded by Gaia; these are the hottest among OB stars, shining with ultraviolet radiation that knocks electrons off hydrogen atoms to give them their ionized state.

    The regions with the highest density of these stars are displayed in pink/purple shades, regions with intermediate density in violet/light blue, and low-density regions in dark blue. Additional information from other astronomical surveys was also used to map concentrations of interstellar dust, shown in green, while known clouds of ionised gas are depicted as red spheres.

    The appearance of ‘spokes’ is a combination of dust clouds blocking the view to stars behind them and a stretching effect of the distribution of stars along the line of sight.

    An interactive version of this map is also available as part of Gaia Sky, a real-time, 3D astronomy visualisation software that was developed in the framework of the Gaia mission at the Astronomisches Rechen-Institut, University of Heidelberg, Germany.

    Further details including annotated version of the map: Mapping and visualising Gaia DR2

    See the full article here .

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    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.

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  • richardmitnick 9:16 am on August 20, 2018 Permalink | Reply
    Tags: , ARC Center of Excellence, Astronomy, , , , Einstein's equivalence principle, , ,   

    From ARC Centres of Excellence via Science Alert: “We May Soon Know How a Crucial Einstein Principle Works in The Quantum Realm” 

    arc-centers-of-excellence-bloc

    From ARC Centres of Excellence

    via

    Science Alert

    1
    (NiPlot/iStock)

    20 AUG 2018
    MICHELLE STARR

    The puzzle of how Einstein’s equivalence principle plays out in the quantum realm has vexed physicists for decades. Now two researchers may have finally figured out the key that will allow us to solve this mystery.

    Einstein’s physical theories have held up under pretty much every classical physics test thrown at them. But when you get down to the very smallest scales – the quantum realm – things start behaving a little bit oddly.

    The thing is, it’s not really clear how Einstein’s theory of general relativity and quantum mechanics work together. The laws that govern the two realms are incompatible with each other, and attempts to resolve these differences have come up short.

    But the equivalence principle – one of the cornerstones of modern physics – is an important part of general relativity. And if it can be resolved within the quantum realm, that may give us a toehold into resolving general relativity and quantum mechanics.

    The equivalence principle, in simple terms, means that gravity accelerates all objects equally, as can be observed in the famous feather and hammer experiment conducted by Apollo 15 Commander David Scott on the Moon.

    It also means that gravitational mass and inertial mass are equivalent; to put it simply, if you were in a sealed chamber, like an elevator, you would be unable to tell if the force outside the chamber was gravity or acceleration equivalent to gravity. The effect is the same.

    “Einstein’s equivalence principle contends that the total inertial and gravitational mass of any objects are equivalent, meaning all bodies fall in the same way when subject to gravity,” explained physicist Magdalena Zych of the ARC Centre of Excellence for Engineered Quantum Systems in Australia.

    “Physicists have been debating whether the principle applies to quantum particles, so to translate it to the quantum world we needed to find out how quantum particles interact with gravity.

    “We realised that to do this we had to look at the mass.”

    According to relativity, mass is held together by energy. But in quantum mechanics, that gets a bit complicated. A quantum particle can have two different energy states, with different numerical values, known as a superposition.

    And because it has a superposition of energy states, it also has a superposition of inertial masses.

    This means – theoretically, at least – that it should also have a superposition of gravitational masses. But the superposition of quantum particles isn’t accounted for by the equivalence principle.

    “We realised that we had to look how particles in such quantum states of the mass behave in order to understand how a quantum particle sees gravity in general,” Zych said.

    “Our research found that for quantum particles in quantum superpositions of different masses, the principle implies additional restrictions that are not present for classical particles – this hadn’t been discovered before.”

    This discovery allowed the team to re-formulate the equivalence principle to account for the superposition of values in a quantum particle.

    The new formulation hasn’t yet been applied experimentally; but, the researchers said, opens a door to experiments that could test the newly discovered restrictions.

    And it offers a new framework for testing the equivalence principle in the quantum realm – we can hardly wait.

    The team’s research has been published in the journal Nature Physics.

    See the full article here .

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    Please help promote STEM in your local schools.

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    The objectives for the ARC Centres of Excellence are to:

    undertake highly innovative and potentially transformational research that aims to achieve international standing in the fields of research envisaged and leads to a significant advancement of capabilities and knowledge
    link existing Australian research strengths and build critical mass with new capacity for interdisciplinary, collaborative approaches to address the most challenging and significant research problems
    develope relationships and build new networks with major national and international centres and research programs to help strengthen research, achieve global competitiveness and gain recognition for Australian research
    build Australia’s human capacity in a range of research areas by attracting and retaining, from within Australia and abroad, researchers of high international standing as well as the most promising research students
    provide high-quality postgraduate and postdoctoral training environments for the next generation of researchers
    offer Australian researchers opportunities to work on large-scale problems over long periods of time
    establish Centres that have an impact on the wider community through interaction with higher education institutes, governments, industry and the private and non-profit sector.

     
  • richardmitnick 8:48 am on August 20, 2018 Permalink | Reply
    Tags: Astronomy, , , , , , KELT-9b   

    From IAC via COSMOS: “The planet KELT-9b literally has an iron sky” 

    IAC

    From Instituto de Astrofísica de Canarias – IAC

    via

    COSMOS

    20 August 2018
    Ben Lewis

    1
    The Gran Telescopio Canarias on Las Palma in the Canary Islands was instrumental in determining the constituents of the exoplanet’s atmosphere. Dominic Dähncke/Getty Images

    KELT-9b, one of the most unlikely planets ever discovered, has surprised astronomers yet again with the discovery that its atmosphere contains the metals iron and titanium, according to research published in the journal Nature.

    2
    NASA/JPL-Caltech

    The planet is truly like no other. Located around 620 light-years away from Earth in the constellation Cygnus, it is known as a Hot Jupiter – which gives a hint to its nature. Nearly three times the size of Jupiter, its surface temperature tops 3780 degrees Celsius – the hottest exoplanet ever discovered. It is even hotter than the surface of some stars. In some ways it straddles the line between a star and a gas-giant exoplanet.

    And it’s that super-hot temperature, created by a very close orbit to its host star, that allows the metals to become gaseous and fill the atmosphere, say the findings from a team led by Jens Hoeijmakers of the University of Geneva in Switzerland.

    On the night of 31 July 2017, as KELT-9b passed across the face of its star, the HARPS-North spectrograph attached to the Telescopio Nazionale Galileo, located the Spanish Canary Island of La Palma, began watching. The telescope recorded changes in colour in the planet’s atmosphere, the result of chemicals with different light-filtering properties.

    Telescopio Nazionale Galileo – Harps North


    Telescopio Nazionale Galileo a 3.58-meter Italian telescope, located at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain, Altitude 2,396 m (7,861 ft)

    By subtracting the plain starlight from the light that had passed through the atmosphere, the team were left with a spectrograph of its chemical make-up.

    They then homed in on titanium and iron, because the relative abundances of uncharged and charged atoms tend to change dramatically at the temperatures seen on KELT-9b. After a complex process of analysis and cross-correlation of results, they saw dramatic peaks in the ionised forms of both metals.

    It has been long suspected that iron and titanium exist on some exoplanets, but to date they have been difficult to detect. Somewhat like Earth, where the two elements are mostly found in solid form, the cooler conditions of most exoplanets means that the iron and titanium atoms are generally “trapped in other molecules,” as co-author Kevin Heng from the University of Bern in Switzerland recently told Space.com.

    However, the permanent heatwave on KELT-9b means the metals are floating in the atmosphere as individual charged atoms, unable to condense or form compounds.

    While this is the first time iron has been detected in an exoplanet’s atmosphere, titanium has previously been detected in the form of titanium dioxide on Kepler 13Ab, another Hot Jupiter. The discovery on KELT-9b however, is the first detection of elemental titanium in an atmosphere.

    KELT-9b’s atmosphere is also known to contain hydrogen, which was easily identifiable without requiring the type of complex analysis needed to identify iron and titanium. However, a study in July [Nature Astronomy] found that the hydrogen is literally boiling off the planet, leading to the hypothesis that its escape could also be dragging the metals higher into the atmosphere, making their detection easier.

    Further studies into KELT-9b’s atmosphere are continuing, with suggestions that announcements of other metals could be forthcoming. In addition, the complex analysis required in this study could be useful for identifying obscure components in the atmospheres of other planets.

    See the full article here.


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    The Instituto de Astrofísica de Canarias(IAC) is an international research centre in Spain which comprises:

    The Instituto de Astrofísica, the headquarters, which is in La Laguna (Tenerife).
    The Centro de Astrofísica en La Palma (CALP)
    The Observatorio del Teide (OT), in Izaña (Tenerife).
    The Observatorio del Roque de los Muchachos (ORM), in Garafía (La Palma).

    Roque de los Muchachos Observatory is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands, at an altitude of 2,396 m (7,861 ft)

    These centres, with all the facilities they bring together, make up the European Northern Observatory(ENO).

    The IAC is constituted administratively as a Public Consortium, created by statute in 1982, with involvement from the Spanish Government, the Government of the Canary Islands, the University of La Laguna and Spain’s Science Research Council (CSIC).

    The International Scientific Committee (CCI) manages participation in the observatories by institutions from other countries. A Time Allocation Committee (CAT) allocates the observing time reserved for Spain at the telescopes in the IAC’s observatories.

    The exceptional quality of the sky over the Canaries for astronomical observations is protected by law. The IAC’s Sky Quality Protection Office (OTPC) regulates the application of the law and its Sky Quality Group continuously monitors the parameters that define observing quality at the IAC Observatories.

    The IAC’s research programme includes astrophysical research and technological development projects.

    The IAC is also involved in researcher training, university teaching and outreachactivities.

    The IAC has devoted much energy to developing technology for the design and construction of a large 10.4 metre diameter telescope, the ( Gran Telescopio CANARIAS, GTC), which is sited at the Observatorio del Roque de los Muchachos.



    Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, SpainGran Telescopio CANARIAS, GTC

     
  • richardmitnick 7:46 am on August 20, 2018 Permalink | Reply
    Tags: Ask Ethan: Is Spacetime Really A Fabric?, Astronomy, , , , Eddington Einstein exibition of gravitational lensing,   

    From Ethan Siegel: “Ask Ethan: Is Spacetime Really A Fabric?” 

    From Ethan Siegel
    Aug 18, 2018

    In General Relativity, even space and time themselves aren’t what they seem.

    Gravity might have been the first fundamental force ever discovered, but in many ways, it remains the least-well understood. We know that it’s always attractive, and that any two masses in the Universe, no matter where they are, will experience its force. When Einstein concocted his general theory of relativity, one of the great advances was to recognize that space and time were combined into a single entity: spacetime. Another was that the presence of matter and energy curved the very fabric of this spacetime, and that curved spacetime, in turn, dictated how matter moved. But is this picture right? Mariusz Wroblewski is skeptical, asking:

    “I’d like somebody to finally acknowledge and admit that showing balls on a bed sheet doesn’t cut it as a picture of reality.”

    I freely acknowledge and admit it. As ubiquitous as pictures of bent sheets or coordinate systems are, they aren’t exactly reflective of the reality we inhabit.

    1
    The spacetime curvature around any massive object is determined by the combination of mass and distance from the center-of-mass. However, this two-dimensional grid-like depiction of spacetime isn’t necessarily the most accurate way to perceive it. (T. PYLE/CALTECH/MIT/LIGO LAB)

    If you’ve ever seen a picture of a bent, two-dimensional grid with masses on it representing space, you’ll know this type of illustration is extremely common. It appears to depict the fabric of space as being curved by the presence of mass, and therefore, any other particle traveling along this fabric will have its path bent towards this gravitational source. The larger the mass and the closer you get to it, the larger the curvature, and therefore, the larger the bending.

    This appears to line up, at least intuitively, with the experiments and observations that have taken place to verify and validate General Relativity over the past nearly 100 years. From the bending of background starlight during a total solar eclipse to the effect of gravitational lensing today, at least qualitatively, the picture appears to agree.

    2
    The results of the 1919 Eddington expedition showed, conclusively, that the General Theory of Relativity described the bending of starlight around massive objects, overthrowing the Newtonian picture. This was the first observational confirmation of Einstein’s General Relativity, and appears to align with the ‘bent-fabric-of-space’ visualization. (THE ILLUSTRATED LONDON NEWS, 1919)

    Eddington Einstein exibition of gravitational lensing

    But what would such a picture actually imply? If space is like a fabric, how does mass curve it?

    It appears as though a mass somehow gets pulled “down” onto the fabric, and then the other particles traveling through that space are pulled “down” by some unseen, mysterious force as well. Clearly, this can’t be right, because there’s no external gravitation at play at all! Additionally, the grid lines curve away from, rather than towards, the mass, which also can’t be right, especially if gravity is attractive.

    Gravity simply is, and it’s merely that the equations that describe General Relativity are geometric in nature. The idea that mass-and-energy curves space can be right, even though this naive visualization must be wrong.

    3
    The idea that space is a fabric has its limitations. It is quite clear that a large mass cannot pull this fabric ‘down’ and cause the other objects within it to move along a curved path. Spacetime may obey geometric equations and be curved, but not like this. (DAVID CHAMPION, MAX PLANCK INSTITUTE FOR RADIO ASTRONOMY)


    Max Planck Institute for Radio Astronomy Bonn Germany

    Instead, we can do better by going to the correct number of spatial dimensions: three.

    Imagine, to start, that we have completely empty space. There are no masses nearby; there’s no radiation; there’s no dark matter, dark energy, neutrinos, or anything else that might cause this space to curve. There’s also no intrinsic curvature.

    Instead, just imagine that space is flat, static, and empty. If we insisted on drawing a grid, like a mathematical overlay, atop space itself, here’s what it would look like.

    4
    We often visualize space as a 3D grid, even though this is a frame-dependent oversimplification when we consider the concept of spacetime. If you place a particle on this grid and allow the Universe to expand, the particle will appear to recede from you. (REUNMEDIA / STORYBLOCKS)

    Now, let’s put a mass down in this spacetime. The mass has got to curve spacetime, but it isn’t actually a fabric: it’s simply the nothingness that makes up the empty Universe itself. The equations of General Relativity tell us how this curvature works, geometrically, but they don’t tell us how to visualize it.

    One brilliant way to do so, however, is to draw your grid lines as though they represent the force experienced by a negligibly-massed, pressure-free dust particle that’s at rest with respect to the new mass. The greater the force that particle would experience, the greater the spacetime curvature. If we were to draw that out, we’d arrive at a very different, potentially more useful picture.

    5
    Instead of an empty, blank, 3D grid, putting a mass down causes what would have been ‘straight’ lines to instead become curved by a specific amount. Note that they appear to drag towards, rather than away from, the mass in question. (CHRISTOPHER VITALE OF NETWORKOLOGIES AND THE PRATT INSTITUTE)

    The biggest problem with this picture is that it’s difficult to draw!

    Thankfully, with the advent of computer animation, we can visualize how space itself curves even with objects in motion. Remember, it isn’t actually a fabric, but rather takes up the entirety of the Universe. Spacetime simply is: it’s what’s left over when we take everything in the Universe away that we’re capable of taking away. When we put things like masses down in the Universe, spacetime is still there, too, but its properties are altered by whatever it is that’s inside it. The larger a mass you put inside it, the more that spacetime gets curved.

    This is true even of a single mass that we simply move around. It could move in a straight line or along a curved path; it could move naturally (because of the motion of other masses) or artificially (because an external force moved it). Either way, it doesn’t make much of a difference. The real issue is that as masses move through space, the geometry describing spacetime changes.

    As a result, the objects residing in that space, whether they’re massive or massless, will change their motion in response to the presence and properties of all the matter and energy within it. John Wheeler’s explanation, that mass tells space how to curve, while curved space tells matter how to move, still holds.

    6
    An animated look at how spacetime responds as a mass moves through it helps showcase exactly how, qualitatively, it isn’t merely a sheet of fabric but all of space itself gets curved by the presence and properties of the matter and energy within the Universe. (LUCASVB)

    You can talk about space as a fabric, but if you do, be aware that what you’re doing is implicitly reducing your perspective down to a two-dimensional analogy. Space in our Universe is three dimensional, and when you combine it with time, you get a four dimensional quantity. When it comes to the notion of spacetime curvature, this is what General Relativity refers to.

    But under no circumstances should you conceive of space as though it’s a material, physical thing; it isn’t. This is only a mathematical structure that we can write down equations to describe: the equations of Einstein’s General Relativity. The fact that matter and radiation respond to that curvature in the exact ways that the equations predict validates this theory, but it doesn’t mean that space is actually a fabric.

    7
    An illustration of gravitational lensing showcases how background galaxies — or any light path — is distorted by the presence of an intervening mass, such as a foreground galaxy cluster. The ‘fabric of space’ analogy is just an analogy, and isn’t physically meaningful. (NASA/ESA)

    We also talk about the expanding Universe in the context that ‘the fabric of space is stretching,’ even though there is no fabric and it isn’t really stretching, or for that matter, changing in any way. What’s happening is simply that the distance between any two points in the Universe is changing according to a particular set of rules in the context of General Relativity. Galaxies, like raisins embedded in a loaf of baking bread, expand away from one another. The wavelength of radiation gets longer too, as though the length of the wave crests and troughs expanded away from one another too.

    But in reality, there isn’t any fabric causing the expansion. In the raisin/bread analogy, the raisins (galaxies) are physically real, but the bread (fabric of space) is just a visualization.

    8
    The ‘raisin bread’ model of the expanding Universe, where relative distances increase as the space (dough) expands. (NASA / WMAP SCIENCE TEAM)

    NASA/WMAP 2001 to 2010

    One of the most paradoxical ideas to wrap your head around in all of physics is that the equations that describe the Universe are just that: equations describing things we can physically observe. We can no more observe the ‘fabric of space’ than we can observe the nothingness of empty spacetime; it simply exists. Any visualization we attempt to assign to it, whether it’s a 2D fabric, a 3D grid, or a baking ball of dough, is just that: a human-inspired creation. The theory itself doesn’t demand it.

    9
    In the big image at left, the many galaxies of a massive cluster called MACS J1149+2223 dominate the scene. Gravitational lensing by the giant cluster brightened the light from the newfound galaxy, known as MACS 1149-JD, some 15 times. At upper right, a partial zoom-in shows MACS 1149-JD in more detail, and a deeper zoom appears to the lower right. This is correct and consistent with General Relativity, and independent of how we visualize (or whether we visualize) space.(NASA/ESA/STSCI/JHU)

    NASA/ESA Hubble Telescope


    What we can observe, however, are the physical objects — the matter and radiation — present within that space. Those are the entities we can measure, and it is the predictions for the behavior of those objects that enables us to test theories like Einstein’s General Relativity. We don’t do very well at accepting mathematics for what it is, so we choose to make analogies to help us picture what’s happening with the Universe. The success of General Relativity rises and falls with observations and measurements. We can observe the measurable consequences of this theory, but not the actual structure of spacetime, even if it’s predicted by underlying theory itself.

    All analogies, in this regard, have limitations and flaws. We can choose a visualization that’s less wrong, perhaps, than a 2D picture of a bent fabric, but there is no correct answer. General Relativity tells us what the Universe does given matter and energy distributed in a specific way, and our observations are consistent with it. We can choose to visualize it in whatever way makes the most sense to us, but all visualizations are inherently flawed. The best we can do is try to comprehend the Universe, as puzzling as it may be, as it actually is.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 12:13 pm on August 19, 2018 Permalink | Reply
    Tags: Astronomy, , , Constellations, ,   

    From Manu Garcia at IAC: “Constellations” 


    From Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    1
    List of 88 constellations in the night sky is divided. It was adopted by the International Astronomical Union in 1930.
    Image Shadowxfox – Own work, GFDL,
    https://commons.wikimedia.org/w/index.php?curid=3791072

    A constellation, in astronomy, is a conventional cluster of stars, whose position in the night sky is apparently unchanged. Peoples, ancient civilizations generally decided by imaginary lines linking, creating virtual silhouettes on the celestial sphere. In the vastness of space, however, the stars are not necessarily a constellation associated locally; and can be hundreds of light years away from each other. In addition, these groups are completely arbitrary, since different cultures have devised different constellations, including by linking the same stars.

    Some constellations were devised centuries ago by the people inhabiting the regions of the Middle East and the Mediterranean. Others, which are further south, received its name from the most recent Europeans to explore these places hitherto unknown for them times, although the peoples who inhabited the southern regions had already named their own constellations according to their beliefs.

    It is customary to separate the constellations into two groups, depending celestial Hemisphere where they are:

    northern constellations, located north of the celestial Ecuador
    southern constellations in the south.

    Since 1928, the International Astronomical Union (IAU) officially decided to regroup the celestial sphere in 88 constellations with precise boundaries, so that every point in the sky to stay within the limits of a figure. Before that year, they were recognized other minor constellations that then fell into oblivion; many, no longer remembered. The work of the constellations final delimitation was carried out mainly by the Belgian astronomer Eugène Joseph Delporte and published by the IAU in 1930.

    To learn more follow the link.

    2
    Constellations of the Northern Hemisphere. Screenshot made on the date and location in the lower frame of the image.

    The stars that can be seen on a clear night are certain figures we call “constellations” and they serve to more easily locate the position of the stars.

    In total, there are 88 groups of stars that appear on the celestial sphere and take their name from religious or mythological figures, animals or objects. This term also refers to defined areas of the celestial sphere comprising groups named stars.

    Drawings oldest known constellations show that the constellations had already been established 4000 BC The Sumerians gave the name to the constellation Aquarius, in honor of their god An, who pours the water of immortality on Earth. Babylonians had divided into 12 equal zodiac signs to 450 BC

    Current constellations of the northern hemisphere who knew little of the Chaldeans and the ancient Egyptians differ. Homer and Hesiod mentioned constellations and the Greek poet Aratus of Soli, gave a verse description of 44 constellations in their Phaenomena. Ptolemy, Greek astronomer and mathematician, in the Almagest, described 48 constellations, of which 47 are still know by the same name.

    Many other cultures grouped stars in constellations, although not always correspond to those of the West. However, some Chinese constellations resemble Western, which suggests the possibility of a common origin.

    In the late sixteenth century, the first European explorers of the South Seas drew maps of the southern hemisphere. The Dutch navigator Pieter Dirckz Keyser, who participated in the exploration of the East Indies in 1595 added new constellations. They were later added other southern constellations by German astronomer Johann Bayer, who published the first comprehensive atlas celestial hemisphere.

    Many others proposed new constellations, but astronomers finally agreed on a list of 88. However, the boundaries of the constellations topic of discussion remained until 1930, when the International Astronomical Union set such limits.

    3
    Constellations of the Southern Hemisphere. Screenshot made on the date and location in the lower frame of the image.

    Constellations 1

    Constellations II

    Constellations III

    Constellations IV

    Constellations V

    To designate the approximately 1,300 bright stars, the genitive of the name of constellations, preceded by a Greek letter used; This system was introduced by Johann Bayer. For example, the famous star Algol in the constellation Perseus, is called Beta Persei.

    Among the best known constellations are those found in the plane of the orbit of the Earth on the background of fixed stars. Are the constellations of the Zodiac. Besides these, some well-known Southern Cross are visible from the hemisferiosur, and Ursa Major, visible from the Northern Hemisphere. These and other constellations allow to locate the position of important reference points, for example, the celestial poles.

    Most constellation of the celestial sphere is the Hydra, containing 68 stars visible to the naked eye. Southern Cross, meanwhile, is the smallest constellation more information.

    The following table is organized alphabetically, according to the Latin nomenclature (general purpose). It also includes the abbreviation generally given to each constellation, the genitive and the Spanish name, link article.

    Screenshots made with Stellarium.
    To learn more about Stellarium follow the link: http://stellarium.org/es/

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Instituto de Astrofísica de Canarias(IAC) is an international research centre in Spain which comprises:

    The Instituto de Astrofísica, the headquarters, which is in La Laguna (Tenerife).
    The Centro de Astrofísica en La Palma (CALP)
    The Observatorio del Teide (OT), in Izaña (Tenerife).
    The Observatorio del Roque de los Muchachos (ORM), in Garafía (La Palma).

    Roque de los Muchachos Observatory is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands, at an altitude of 2,396 m (7,861 ft)

    These centres, with all the facilities they bring together, make up the European Northern Observatory(ENO).

    The IAC is constituted administratively as a Public Consortium, created by statute in 1982, with involvement from the Spanish Government, the Government of the Canary Islands, the University of La Laguna and Spain’s Science Research Council (CSIC).

    The International Scientific Committee (CCI) manages participation in the observatories by institutions from other countries. A Time Allocation Committee (CAT) allocates the observing time reserved for Spain at the telescopes in the IAC’s observatories.

    The exceptional quality of the sky over the Canaries for astronomical observations is protected by law. The IAC’s Sky Quality Protection Office (OTPC) regulates the application of the law and its Sky Quality Group continuously monitors the parameters that define observing quality at the IAC Observatories.

    The IAC’s research programme includes astrophysical research and technological development projects.

    The IAC is also involved in researcher training, university teaching and outreach activities.

    The IAC has devoted much energy to developing technology for the design and construction of a large 10.4 metre diameter telescope, the ( Gran Telescopio CANARIAS, GTC), which is sited at the Observatorio del Roque de los Muchachos.


    Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, SpainGran Telescopio CANARIAS, GTC

     
  • richardmitnick 9:44 am on August 19, 2018 Permalink | Reply
    Tags: "Discovery of a structurally ‘inside-out’ planetary nebula, , Astronomy, , , , , Planetary nebula HuBi   

    From Astrobiology Magazine: “Discovery of a structurally ‘inside-out’ planetary nebula” 

    Astrobiology Magazine

    From Astrobiology Magazine

    Aug 18, 2018

    1
    Planetary nebula HuBi 1 (left) and another planetary nebula Abell39 (right, 6800 light years away from our solar system). (HuBi 1 image adopted from Guerrero, Fang, Miller Bertolami, et al., 2018, Nature Astronomy, tmp, 112. Image credit for Abell39: The 3.5m WIYN Telescope, National Optical Astronomical Observatory, NSF.)

    NOAO WIYN 3.5 meter telescope interior


    NOAO WIYN 3.5 meter telescope at Kitt Peak, AZ, USA, Altitude 2,096 m (6,877 ft)

    The Instituto de Astrofísica de Andalucía (IAA-CSIC) in Spain, the Laboratory for Space Research (LSR) of the University of Hong Kong (HKU), and an International team comprising scientists from Argentina, Mexico and Germany have discovered the unusual evolution of the central star of a planetary nebula in our Milky Way. This extraordinary discovery sheds light on the future evolution, and more importantly, the ultimate fate of the Sun.

    The discovery of a structurally ‘inside-out’ planetary nebula — the ionized material that surrounds a white dwarf — was just reported online in Nature Astronomy. This is also the eighth research paper produced by HKU LSR with its international collaborators in the Nature journals since 2017.

    The research team believes this inverted ionization structure of the nebula is resulted from the central star undergoing a ‘born-again’ event, ejecting material from its surface and creating a shock that excites the nebular material.

    Planetary nebulae are ionized clouds of gas formed by the hydrogen-rich envelopes of low- and intermediate-mass stars ejected at late evolutionary stages. As these stars age, they typically strip their outer layers, forming a ‘wind’. As the star transitions from its red giant phase to become a white dwarf, it becomes hotter, and starts ionizing the material in the surrounding wind. This causes the gaseous material closer to the star to become highly ionized, while the gas material further out is less so.

    Studying the planetary nebula HuBi 1 (17,000 light years away and nearly 5 billion years ahead of our solar system in evolution), however, Dr Martín Guerrero et al. found the reverse: HuBi 1’s inner regions are less ionized, while the outer regions more so. Analysing the central star, with the participation of top theoretical astrophysicists, the authors found that it is surprisingly cool and metal-rich, and is evolved from a low-mass progenitor star which has a mass 1.1 times of the Sun.

    The authors suggest that the inner nebula was excited by the passage of a shockwave caused by the star ejecting matter unusually late in its evolution. The stellar material cooled to form circumstellar dust, obscuring the star; this well explains why the central star’s optical brightness has diminished rapidly over the past 50 years. In the absence of ionizing photons from the central star, the outer nebula has begun recombining — becoming neutral. The authors conclude that, as HuBi 1 was roughly the same mass as the Sun, this finding provides a glimpse of a potential future for our solar system.

    Dr Xuan Fang, co-author of the paper and a postdoctoral fellow at the HKU LSR and Department of Physics, said the extraordinary discovery resolves a long-lasting question regarding the evolutionary path of metal-rich central stars of planetary nebulae. Dr Fang has been observing the evolution of HuBi 1 early since 2014 using the Spanish flagship telescope Nordic Optical Telescope and was among the first astrophysicists to discover its inverted ionization structure.


    Nordic Optical telescope, at Roque de los Muchachos Observatory, La Palma in the Canary Islands, Spain, Altitude 2,396 m (7,861 ft)

    He said: “After noting HuBi 1’s inverted ionization structure and the unusual nature of its central star, we looked closer to find the reasons in collaboration with top theoretical astrophysicists in the world. We then came to realize that we had caught HuBi 1 at the exact moment when its central star underwent a brief ‘born-again’ process to become a hydrogen-poor [WC] and metal-rich star, which is very rare in white dwarf stars evolution.”

    Dr Fang, however, said the discovery would not alter the fate of the Earth. He remarked: “Our findings suggest that the Sun may also experience a ‘born-again’ process while it is dying out in about 5 billion years from now; but way before that event, our earth will be engulfed by the Sun when it turns into a superhot red giant and nothing living will survive.”

    HKU LSR Acting Director Professor Quentin Parker is exceptionally pleased with the findings of this international collaboration. He said: “I am delighted by this latest important contribution by Dr Xuan Fang who played a key role in this very unusual discovery of the international project. This exciting result in the area of evolved stars adds to several other impressive findings that members of the LSR have been producing over the last two years in astrophysics and planetary science research. It demonstrates yet again that the universe still has surprises for us. The LSR has an excellent and growing reputation in late-stage stellar evolution, high energy astrophysics, and planetary sciences and I expect this to continue.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 8:07 am on August 19, 2018 Permalink | Reply
    Tags: Astronomy, , , , Dr Farah Alibay, , , When flying to Mars is your day job,   

    From BBC Presented by via Science Node: Women in STEM- “When flying to Mars is your day job” Dr Farah Alibay 

    Science Node bloc
    Science Node

    BBC
    BBC

    17 August 2018
    Mary Halton

    1
    “As a kid… I never really thought there was a job where you worked on spacecraft.” Farah Alibay

    Sending missions to Mars for a living sounds like a dream job. But not every day can be launch day – so what do Nasa’s spacecraft engineers get up to the rest of the time?

    Dr Farah Alibay is based at Nasa’s Jet Propulsion Laboratory (JPL) and works on the InSight mission – which lifted off to Mars in May 2018.

    NASA/Mars Insight Lander

    It aims to land on the planet in November and have a look inside – taking its internal temperature and listening for “Marsquakes” to learn more about how our nearest neighbour formed.

    Now halfway to the Red Planet and running to a Mars day rather than an Earth one, InSight is looked after by a dedicated team who regularly check in with the spacecraft on its long journey, including Dr Alibay.

    She shared a day at her job with the BBC.

    2
    “My official title is Payload Systems Engineer.” Farah Alibay/JPL/NASA

    What’s a working day like for you?

    So it’s sort of weird that we’re on our way to Mars… and it’s really boring! But really that’s the way you want it to be. Everything’s going fine, so we’ll just keep going!

    Before we launched, my job was to make sure that all the instruments were integrated properly on the spacecraft, and that they were tested properly.

    Right now while we’re sort of in this limbo time where we’re waiting, my job is to help the teams prepare for operations.

    3
    “I love that a lot of my work is collaborative, so I spend a lot of time working with other people.” Farah Alibay/JPL/NASA

    It’s kind of an engineer’s job to worry. Because it’s always the things you never imagined would happen that happen.

    We’re halfway to Mars right now, literally this week is the halfway point, and I’ve been getting Mars landing nightmares.

    Less than half the missions that have tried landing on Mars have succeeded. So it’s a little scary when you spend that much time on a spacecraft and it’s all going to come down to that one day – Monday 16 November. We’ll see what happens!

    The way that we operate the spacecraft is that we basically write commands. Each one is a piece of code that we send up to the spacecraft to tell it what to do when it’s on the ground.

    When the spacecraft is sleeping at night, we work. So we get all the data down, look at it and tell the spacecraft: “Hey InSight, tomorrow these are the tasks I want you to do!”

    4

    And then we uplink it, right before it wakes up in the morning. Then we go to bed and the spacecraft does its work.

    5
    Being ‘on console’ means working from mission control, home to the Deep Space Network which communicates with Nasa’s distant missions. Farah Alibay/JPL/NASA

    But because the Mars day shifts every day, we also have to shift our schedule by an hour every day. So the first day we’ll start at 6am, and then [the next] will be 7am… 8am… 9am… and then we take a day off.

    About once a week we’ve been turning on a different instrument and doing a checkout. So just making sure that everything was ok from launch, that the instrument is still behaving properly.

    One of those tests is happening today. We do that from console because the spacecraft is being operated at Lockheed Martin in Denver, and the instrument teams are looking at that data from Europe, so we use a system that allows us all to talk to each other.

    What’s your favourite aspect of your job?

    No matter what I do on a given day, no one’s really done it before. And I think that’s what’s exciting. We don’t just do incremental change, we do brand new things.

    6
    Landing sites are carefully chosen, as many of the spacecraft that have tried to land on Mars have met with an unpleasant end. Farah Alibay/JPL/NASA

    It helps put things in perspective, because my job does involve spending days looking at spreadsheets sometimes, or building PowerPoint slides, or answering emails. I definitely do a lot of that, so it’s just as boring sometimes as other jobs.

    But putting it into perspective… even on a boring day my spacecraft is still on its way to Mars!

    7
    Team X brainstorm: “You can go to them and say I have this wild idea, and they make you make this wild idea into a mission concept.” Farah Alibay/JPL/NASA

    How did you become a Nasa engineer?

    So my path is a little strange. I actually grew up in England… I grew up in Manchester and went to university at Cambridge and then ended up at MIT. When I was at MIT I interned at JPL.

    One of the things I try to do is mentor other women interns, because I had really great mentors when I was an intern, and that’s how I got my job.

    8
    Dr Alibay with JPL intern Taleen Sarkissian.Farah Alibay/JPL/NASA

    What’s next, after Mars?

    I will be part of the InSight team until the end of the instrument deployment, so probably until February 2019.

    My dream actually… we don’t have a mission on that yet, but my favourite moon is Saturn’s Enceladus.

    The geysers at the south pole of Enceladus are incredible, and I’ve worked on mission concepts before that we’ve proposed to Nasa to fly through those plumes. One day I want there to be a mission to do that.

    We’re focused on finding life in the Solar System right now, and I think a lot of us believe that in our lifetime… if there’s life in the Solar System we’re probably going find it.

    So I want to be part of the team that finds it.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Science Node is an international weekly online publication that covers distributed computing and the research it enables.

    “We report on all aspects of distributed computing technology, such as grids and clouds. We also regularly feature articles on distributed computing-enabled research in a large variety of disciplines, including physics, biology, sociology, earth sciences, archaeology, medicine, disaster management, crime, and art. (Note that we do not cover stories that are purely about commercial technology.)

    In its current incarnation, Science Node is also an online destination where you can host a profile and blog, and find and disseminate announcements and information about events, deadlines, and jobs. In the near future it will also be a place where you can network with colleagues.

    You can read Science Node via our homepage, RSS, or email. For the complete iSGTW experience, sign up for an account or log in with OpenID and manage your email subscription from your account preferences. If you do not wish to access the website’s features, you can just subscribe to the weekly email.”

     
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