вторник, 31 июля 2018 г.

HiPOD (31 July 2018): It’s All about That Flow   – There are a…


HiPOD (31 July 2018): It’s All about That Flow


   – There are a number of crevasse-like features here. (297 km above the surface, less than 5 km across.)


NASA/JPL/University of Arizona


https://xissufotoday.space/2018/07/hipod-31-july-2018-its-all-about-that-flow-there-are-a/

Геода грозовое яйцо из магмы вулкана

Гром-яйцо


Thundereggs встречаются в потоках риолитовой лавы. Они образуются в газовых карманах в лаве, которые действуют как формы, от действия воды, просачивающейся через пористую породу, несущую кремнезем в растворе. Охлажденные пузырьки постепенно заполнялись водой, просачивающейся через пористую породу с богатыми количествами кремнезема (кварца). Отложения выровнялись и заполняли полость, сначала более темным материалом матрицы, затем внутренним ядром агата или халцедона. Различные цвета происходят из-за различий в минералах, найденных в почве и скале, через которую прошла вода.


Thunder Egg



 


https://xissufotoday.space/2018/07/%d0%b3%d0%b5%d0%be%d0%b4%d0%b0-%d0%b3%d1%80%d0%be%d0%b7%d0%be%d0%b2%d0%be%d0%b5-%d1%8f%d0%b9%d1%86%d0%be-%d0%b8%d0%b7-%d0%bc%d0%b0%d0%b3%d0%bc%d1%8b-%d0%b2%d1%83%d0%bb%d0%ba%d0%b0%d0%bd%d0%b0/

Symphony of Stars: The Science of Stellar Sound Waves



This artist’s concept shows how sound waves travel through a hypothetical star that has an orbiting planet.
Credits: Gabriel Pérez Díaz, Instituto de Astrofísica de Canarias


We can’t hear it with our ears, but the stars in the sky are performing a concert, one that never stops. The biggest stars make the lowest, deepest sounds, like tubas and double basses. Small stars have high-pitched voices, like celestial flutes. These virtuosos don’t just play one “note” at a time, either — our own Sun has thousands of different sound waves bouncing around inside it at any given moment.


Understanding these stellar harmonies represents a revolution in astronomy. By “listening” for stellar sound waves with telescopes, scientists can figure out what stars are made of, how old they are, how big they are and how they contribute to the evolution of our Milky Way galaxy as a whole. The technique is called asteroseismology. Just as earthquakes (or Earth’s seismic waves) tell us about the inside of Earth, stellar waves — resulting in vibrations or “star quakes” — reveal the secret inner workings of stars.  


NASA’s Kepler space telescope, now approaching the end of its mission, has been a key player in that revolution, delivering observations of waves in tens of thousands of stars since its 2009 launch.


NASA’s Transiting Exoplanet Survey Satellite (TESS), which launched in April 2018, may observe sound waves in up to one million red giants — the massive, evolved stars that represent what our Sun will look like in about 5 billion years. While both Kepler and TESS are most famous for hunting for planets beyond our solar system (exoplanets), they are also powerful, sensitive tools for detecting stellar vibrations. And the more we know about stars, the more we know about planets that orbit them.

Continue reading this story


Written by Elizabeth Landau



Editor: Tony Greicius




Archive link


https://xissufotoday.space/2018/07/symphony-of-stars-the-science-of-stellar-sound-waves/

Колебания Земли во время землетрясения...

3D satellite, GPS earthquake maps isolate impacts in real time




https://xissufotoday.space/2018/07/%d0%ba%d0%be%d0%bb%d0%b5%d0%b1%d0%b0%d0%bd%d0%b8%d1%8f-%d0%b7%d0%b5%d0%bc%d0%bb%d0%b8-%d0%b2%d0%be-%d0%b2%d1%80%d0%b5%d0%bc%d1%8f-%d0%b7%d0%b5%d0%bc%d0%bb%d0%b5%d1%82%d1%80%d1%8f%d1%81%d0%b5%d0%bd/

Малахит

 




Malachite







 







Formula: Cu2CO3(OH)2

System: Monoclinic

Colour: Bright green, with …

Lustre: Adamantine, Vitreous, Silky, Dull, Earthy

Hardness: 3½ – 4

Name: Named in antiquity (see Pliny the Elder, 79 CE) molochitus after the Greek μαλαχή, “mallows,” in allusion to the green color of the leaves. Known in the new spelling, malachites, at least by 1661.

Locality: Nizhne-Taglisk, Ural Mountains, Russia.


 


Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and spaces, deep underground, where the water table and hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare but do occur as slender to acicular prisms. Pseudomorphs after more tabular or blocky azurite crystals also occur.


Physical Properties of Malachite



Cleavage: {201} Perfect, {010} Fair

Color: Green, Dark green, Blackish green.

Density: 3.6 – 4, Average = 3.8

Diaphaneity: Translucent to subtranslucent to opaque

Fracture: Uneven – Flat surfaces (not cleavage) fractured in an uneven pattern.

Hardness: 3.5-4 – Copper Penny-Fluorite

Luminescence: Non-fluorescent.

Luster: Vitreous – Silky

Streak: light green



 



Azurite, Malachite. Locality: Morenci, Copper Mountain District, Shannon Mts, Greenlee Co., Arizona, USA. Dimensions: 4.4 cm x 4.1 cm x 2.2 cm. Photo Copyright © Rob Lavinsky & irocks.com

Malachite. Locality: Brixlegg – Rattenberg, Brixlegg – Schwaz area, Inn valley, North Tyrol, Tyrol, Austria. FOV: 15 mm. Photo Copyright © Antonio Borrelli

Malachite. Locality: Brixlegg – Rattenberg, Brixlegg – Schwaz area, Inn valley, North Tyrol, Tyrol, Austria. FOV: 22 mm. Photo Copyright © Manfred Kampf

Malachite, Azurite. Locality: Seabra, Bahia, Brazil. Dimensions: 4.5 cm. Photo Copyright © Dick Dionne

http://www.geologypage.com




https://xissufotoday.space/2018/07/%d0%bc%d0%b0%d0%bb%d0%b0%d1%85%d0%b8%d1%82/

2018 July 31 Layers of the South Pole of Mars Image Credit…


2018 July 31


Layers of the South Pole of Mars
Image Credit & License: ESA/DLR/FU Berlin; Bill Dunford


Explanation: What lies beneath the layered south pole of Mars? A recent measurement with ground-penetrating radar from ESA’s Mars Express satellite has detected a bright reflection layer consistent with an underground lake of salty water. The reflection comes from about 1.5-km down but covers an area 200-km across. Liquid water evaporates quickly from the surface of Mars, but a briny confined lake, such as implied by the radar reflection, could last much longer and be a candidate to host life such as microbes. Pictured, an infrared, green, and blue image of the south pole of Mars taken by Mars Express in 2012 shows a complex mixture of layers of dirt, frozen carbon dioxide, and frozen water.


∞ Source: apod.nasa.gov/apod/ap180731.html


https://xissufotoday.space/2018/07/2018-july-31-layers-of-the-south-pole-of-mars-image-credit/

понедельник, 30 июля 2018 г.

Stellar Corpse Reveals Origin of Radioactive Molecules




Radioactive molecules in the remains of a stellar collision




Artist’s impression of stellar collision



The position of Nova Vul 1670 in the constellation of Vulpecula 


Wide-field view of the sky around Nova Vul 1670




Observations using ALMA find radioactive isotope aluminium-26 from the remnant CK Vulpeculae


Astronomers using ALMA and NOEMA have made the first definitive detection of a radioactive molecule in interstellar space. The radioactive part of the molecule is an isotope of aluminium. The observations reveal that the isotope was dispersed into space after the collision of two stars, that left behind a remnant known as CK Vulpeculae. This is the first time that a direct observation has been made of this element from a known source. Previous identifications of this isotope have come from the detection of gamma rays, but their precise origin had been unknown.


The team, led by Tomasz Kamiński (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA), used the Atacama Large Millimeter/submillimeter Array (ALMA) and the NOrthern Extended Millimeter Array (NOEMA) to detect a source of the radioactive isotope aluminium-26. The source, known as CK Vulpeculae, was first seen in 1670 and at the time it appeared to observers as a bright, red “new star”. Though initially visible with the naked eye, it quickly faded and now requires powerful telescopes to see the remains of this merger, a dim central star surrounded by a halo of glowing material flowing away from it.



348 years after the initial event was observed, the remains of this explosive stellar merger have led to the clear and convincing signature of a radioactive version of aluminum, known as aluminium-26. This is the first unstable radioactive molecule definitively detected outside of the Solar System. Unstable isotopes have an excess of nuclear energy and eventually decay into a stable form.

This first observation of this isotope in a star-like object is also important in the broader context of galactic chemical evolution,” notes Kamiński. “This is the first time an active producer of the radioactive nuclide aluminum-26 has been directly identified.


Kamiński and his team detected the unique spectral signature of molecules made up of aluminum-26 and fluorine (26AlF) in the debris surrounding CK Vulpeculae, which is about 2000 light-years from Earth. As these molecules spin and tumble through space, they emit a distinctive fingerprint of millimetre-wavelength light, a process known as rotational transition. Astronomers consider this the “gold standard” for detections of molecules [1].


The observation of this particular isotope provides fresh insights into the merger process that created CK Vulpeculae. It also demonstrates that the deep, dense, inner layers of a star, where heavy elements and radioactive isotopes are forged, can be churned up and cast into space by stellar collisions.


We are observing the guts of a star torn apart three centuries ago by a collision,” remarked Kamiński.


The astronomers also determined that the two stars that merged were of relatively low mass, one being a red giant star with a mass somewhere between 0.8 and 2.5 times that of our Sun.


Being radioactive, aluminium-26 will decay to become more stable and in this process one of the protons in the nucleus decays into a neutron. During this process, the excited nucleus emits a photon with very high energy, which we observe as a gamma ray [2].


Previously, detections of gamma ray emission have shown that around two solar masses of aluminium-26 are present across the Milky Way, but the process that created the radioactive atoms was unknown. Furthermore, owing to the way that gamma rays are detected, their precise origin was also largely unknown. With these new measurements, astronomers have definitively detected for the first time an unstable radioisotope in a molecule outside of our Solar System.


At the same time, however, the team have concluded that the production of aluminium-26 by objects similar to CK Vulpeculae is unlikely to be the major source of aluminium-26 in the Milky Way. The mass of aluminium-26 in CK Vulpeculae is roughly a quarter of the mass of Pluto, and given that these events are so rare, it is highly unlikely that they are the sole producers of the isotope in the Milky Way galaxy. This leaves the door open for further studies into these radioactive molecules.



Notes



[1] The characteristic molecular fingerprints are usually taken from laboratory experiments. In the case of 26AlF, this method is not applicable because 26-aluminium is not present on Earth. Laboratory astrophysicists from the University of Kassel/Germany therefore used the fingerprint data of stable and abundant 27AlF molecules to derive accurate data for the rare 26AlF molecule.



[2] Aluminium-26 contains 13 protons and 13 neutrons in its nucleus (one neutron fewer than the stable isotope, aluminium-27). When it decays aluminium-26 becomes magnesium-26, a completely different element.



More Information


This research was presented in the paper, Astronomical detection of a radioactive molecule 26AlF in a remnant of an ancient explosion, which will appear in Nature Astronomy.



The team is composed of Tomasz Kamiński (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Romuald Tylenda (N. Copernicus Astronomical Center, Warsaw, Poland), Karl M. Menten (Max-Planck-Institut für Radioastronomie, Bonn, Germany), Amanda Karakas (Monash Centre for Astrophysics, Melbourne, Australia), Jan Martin Winters (IRAM, Grenoble, France), Alexander A. Breier (Laborastrophysik, Universität Kassel, Germany), Ka Tat Wong (Monash Centre for Astrophysics, Melbourne, Australia), Thomas F. Giesen (Laborastrophysik, Universität Kassel, Germany) and Nimesh A. Patel (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA).



ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.



Links




Contacts 


Tomasz Kamiński
Harvard-Smithsonian Center for Astrophysics
Cambridge, Massachusetts, USA
Email:
tomasz.kaminski@cfa.harvard.edu


Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670
Email:
pio@eso.org



Source: ESO/News





Archive link


https://xissufotoday.space/2018/07/stellar-corpse-reveals-origin-of-radioactive-molecules/

HiPOD (30 July 2018): The Bedforms, They are A-Changin’   This…




HiPOD (30 July 2018): The Bedforms, They are A-Changin’


   This is in Zephyria Planum. (304 km above the surface. Black and white is less than 5 km across; enhanced color is less than 1 km.)


NASA/JPL/University of Arizona


https://xissufotoday.space/2018/07/hipod-30-july-2018-the-bedforms-they-are-a-changin-this/

Prehistoric Metalworking Reconstructions, Doncaster Museum and…






Prehistoric Metalworking Reconstructions, Doncaster Museum and Gallery, Yorkshire, 29.7.18.


Source link


https://xissufotoday.space/2018/07/prehistoric-metalworking-reconstructions-doncaster-museum-and/

Plant Power Affecting over 320 million people worldwide, Type…


Plant Power


Affecting over 320 million people worldwide, Type 2 diabetes is a globally-significant condition characterised by high blood glucose levels. Current drugs operate by inhibiting enzymes that break down sugar chains into glucose units, but this can cause unpleasant side-effects, from flatulence to diarrhoea. Searching for a solution led to the discovery of montbretin A (MbA), a compound found in the bulbs, or corms, of the widespread African flowering plant montbretia (pictured). Tests found that MbA blocks another enzyme, known as HPA, to decrease blood glucose without the side-effects. Researchers are now investigating how montbretia plants make MbA, to seek out ways of mass-producing it for the pharmaceutical industry. Recent work identified the enzymes required to produce some intermediate compounds on the pathway towards MbA, including mini-MbA, which also inhibits HPA. Introducing the required genes from montbretia enabled the synthesis of mini-MbA in transformed tobacco plants, a first step towards larger-scale production.


Written by Emmanuelle Briolat



You can also follow BPoD on Instagram, Twitter and Facebook


Archive link


https://xissufotoday.space/2018/07/plant-power-affecting-over-320-million-people-worldwide-type/

Prehistoric Pottery, Doncaster Museum and Gallery, Yorkshire,…








Prehistoric Pottery, Doncaster Museum and Gallery, Yorkshire, 29.7.18.


Source link


https://xissufotoday.space/2018/07/prehistoric-pottery-doncaster-museum-and-gallery-yorkshire/

Rock Art Design, Doncaster Museum and Gallery, Yorkshire,…


Rock Art Design, Doncaster Museum and Gallery, Yorkshire, 29.7.18.


Source link


https://xissufotoday.space/2018/07/rock-art-design-doncaster-museum-and-gallery-yorkshire/

2018 July 30 Lunar Eclipse over Rio Image Credit: Carlos…


2018 July 30


Lunar Eclipse over Rio
Image Credit: Carlos ‘Kiko’ Fairbairn


Explanation: Moonrise doesn’t usually look this interesting. For one thing, the full moon is not usually this dark – but last Friday the moon rose here as it simultaneously passed through the shadow of the Earth. For another thing, the Moon does not usually look this red – but last Friday it was slightly illuminated by red sunlight preferentially refracted through the Earth’s atmosphere. Next, the Moon doesn’t usually rise next to a planet, but since Mars was also coincidently nearly opposite the Sun, the red planet was visible to the full moon’s upper right. Finally, from the vantage point of most people, the Moon does not usually rise over Rio de Janeiro in Brazil. Last Friday’s sunset eclipse, however, specifically its remarkable Micro Blood Moon Total Lunar Eclipse, was captured from Rio’s Botofogo Beach, along with an unusually large crowd of interested onlookers.


∞ Source: apod.nasa.gov/apod/ap180730.html


https://xissufotoday.space/2018/07/2018-july-30-lunar-eclipse-over-rio-image-credit-carlos/

Galaxy outskirts likely hunting grounds for dying massive stars and black holes

Findings from a Rochester Institute of Technology study provide further evidence that the outskirts of spiral galaxies host massive black holes. These overlooked regions are new places to observe gravitational waves created when the massive bodies collide, the authors report.











Galaxy outskirts likely hunting grounds for dying massive stars and black holes
This Chandra X-ray photograph shows Cassiopeia A, the youngest supernova remnant in the Milky Way
[Credit: NASA/CXC/MIT/UMass Amherst/M.D.Stage et al.]

The study winds back time on massive black holes by analyzing their visible precursors–supernovae with collapsing cores. The slow decay of these massive stars creates bright signatures in the electromagnetic spectrum before stellar evolution ends in black holes.


Using data from the Lick Observatory Supernova Search, a survey of nearby galaxies, the team compared the supernovae rate in outer spiral galaxies with that of known hosts–dwarf/satellite galaxies–and found comparable numbers for typical spiral outskirts and typical dwarf galaxies, roughly two core-collapse supernovae per millennium.


Low levels of elements heavier than hydrogen and helium found in dwarf/satellite galaxies create favorable conditions for massive black holes to form and create binary pairs. A similar galactic environment in the outer disks of spiral galaxies also creates likely hunting grounds for massive black holes, said Sukanya Chakrabarti, lead author and assistant professor in the RIT School of Physics and Astronomy.


“If these core-collapse supernovae are the predecessors to the binary black holes detected by LIGO (Laser Interferometer Gravitational-wave Observatory), then what we’ve found is a reliable method of identifying the host galaxies of LIGO sources,” said Chakrabarti. “Because these black holes have an electromagnetic counterpart at an earlier stage in their life, we can pinpoint their location in the sky and watch for massive black holes.”


The study’s findings complement Chakrabarti’s 2017 study, which showed that the outer parts of spiral galaxies could contribute to LIGO detection rates. The regions form stars at a comparable rate to dwarf galaxies and are low in heavy element content, creating a conducive home for massive black holes. The current study isolates potential candidates within these favorable galactic environments.


“We see now that these are both important contributors,” Chakrabarti said. “The next step is to do deeper surveys to see if we can improve the rate.”


Co-author Brennan Dell, a recent graduate from RIT’s computer science program, analyzed the data with Chakrabarti during his undergraduate co-op.


“This work may help us determine which galaxies to be on the lookout for electromagnetic counterparts of massive black holes,” Dell said.


The study, “Supernova Rate beyond the Optical Radius,” will appear in an upcoming issue of Astrophysical Journal Letters.



TANN



Archive


https://xissufotoday.space/2018/07/galaxy-outskirts-likely-hunting-grounds-for-dying-massive-stars-and-black-holes/

Fluorite | #Geology #GeologyPage #Mineral Locality: Xianghuapu…


Fluorite | #Geology #GeologyPage #Mineral


Locality: Xianghuapu Mine (Maiwan Mine), Xianghualing Sn-polymetallic ore field, Linwu Co., Chenzhou Prefecture, Hunan Province, China


Dimensions: 9.3 × 6.3 × 4.0 cm


Photo Copyright © Crystal Classics


Geology Page

www.geologypage.com


https://xissufotoday.space/2018/07/fluorite-geology-geologypage-mineral-locality-xianghuapu/

Carminite | #Geology #GeologyPage #Mineral Locality: Clara…


Carminite | #Geology #GeologyPage #Mineral


Locality: Clara Mine, Wolfach, Black Forest, Baden-Württemberg, Germany

Size: 1.2 × 2.3 × 1.2 cm


Photo Copyright © Mintreasure /e-rocks.com


Geology Page

www.geologypage.com


https://xissufotoday.space/2018/07/carminite-geology-geologypage-mineral-locality-clara/

Fluorite | #Geology #GeologyPage #Mineral Locality: Clara…


Fluorite | #Geology #GeologyPage #Mineral


Locality: Clara Mine, Wolfach, Black Forest, Baden-Württemberg, Germany


Size: 5.7 × 5.7 × 4.2 cm


Photo Copyright © Viamineralia /e-rocks.com


Geology Page

www.geologypage.com


https://xissufotoday.space/2018/07/fluorite-geology-geologypage-mineral-locality-clara/

Pair of 2s? Well I’ve got a Paramecium. Image of the Week – July…


Pair of 2s? Well I’ve got a Paramecium. Image of the Week – July 30, 2018


CIL:41402 http://www.cellimagelibrary.org/images/41402


Description: Differential interference contrast image of a Paramecium (unicellular ciliate protozoa) surface. The image shows three water vacuoles contracting. Specimen observed at 100x. Judges’ Special Award for Technical Merit, 2010 Olympus BioScapes Digital Imaging Competition®.


Authors: Norman Shedlo and 2010 Olympus BioScapes Digital Imaging Competition®


Licensing: Attribution Non-Commercial No Derivatives: This image is licensed under a Creative Commons Attribution, Non-Commercial, No Derivatives License


Archive link


https://xissufotoday.space/2018/07/pair-of-2s-well-ive-got-a-paramecium-image-of-the-week-july/

Prehistoric Tools and Food, Doncaster Museum and Gallery,…







Prehistoric Tools and Food, Doncaster Museum and Gallery, Doncaster, Yorkshire, 29.7.18.


Source link


https://xissufotoday.space/2018/07/prehistoric-tools-and-food-doncaster-museum-and-gallery/

Black holes really just ever-growing balls of string

Black holes aren’t surrounded by a burning ring of fire after all, suggests new research. Some physicists have believed in a “firewall” around the perimeter of a black hole that would incinerate anything sucked into its powerful gravitational pull.











Black holes really just ever-growing balls of string

Credit: Ohio State University



But a team from The Ohio State University has calculated an explanation of what would happen if an electron fell into a typical black hole, with a mass as big as the sun.


“The probability of the electron hitting a photon from the radiation and burning up is negligible, dropping even further if one considers larger black holes known to exist in space,” said Samir Mathur, a professor of physics at Ohio State. The study appears in the Journal of High Energy Physics.


The new study builds on previous work from 2004 led by Mathur that theorized that black holes are basically like giant, messy balls of yarn — “fuzzballs” that gather more and more heft as new objects are sucked in. That theory, Mathur said, resolved the famous black hole “information paradox” outlined by Steven Hawking in 1975. Hawking’s research had concluded that particles entering a black hole can never leave. But that ran counter to the laws of quantum mechanics, creating the paradox.


The firewall argument emerged in 2012, when four physicists from the University of California, Santa Barbara argued that any object like a fuzzball would have to be surrounded by a ring of fire that will burn any object before it could reach the fuzzball’s surface.


“What we’ve shown in this new study is a flaw in the firewall argument,” Mathur said.


Credit: Ohio State University


Black holes are places in space with such immense gravitational pull that not even light can escape once it’s captured. Their powerful pull condenses any matter black holes draw in. They are invisible, but scientists have established that black holes can range from tiny to huge, estimations that are based on the behavior of stars and gas surrounding the black hole.


After months of mathematical machinations, Mathur and his team arrived at their by-the-numbers explanation to support their theory discounting the firewall. It’s built on string theory, the scientific notion that the universe is composed of subatomic string-like tubes of energy. The belief is rooted in the marriage of quantum mechanics (which concerns itself with the mathematics of subatomic particles) and Albert Einstein’s theory of relativity.


Mathur has always counted himself among those scientists who are firewall skeptics.


“The question is ‘Where does the black hole grab you?’ We think that as a person approaches the horizon, the fuzzball surface grows to meet it before it has a chance to reach the hottest part of the radiation, and this is a crucial finding in this new physics paper that invalidates the firewall argument,” he said.


“Once a person falling into the black hole is tangled up in strings, there’s no easy way to decide what he will feel.


“The firewall argument had seemed like a quick way to prove that something falling through the horizon burns up. But we now see that there cannot be any such quick argument; what happens can only be decided by detailed calculations in string theory,” Mathur said.


Author: Misti Crane | Source: Ohio State University [July 26, 2018]



TANN



Archive


https://xissufotoday.space/2018/07/black-holes-really-just-ever-growing-balls-of-string/

Researchers discover thin gap on stellar family portrait

A thin gap has been discovered on the Hertzsprung-Russell Diagram (HRD), the most fundamental of all maps in stellar astronomy, a finding that provides new information about the interior structures of low mass stars in the Milky Way Galaxy, according to a study led by astronomers at Georgia State University.











Researchers discover thin gap on stellar family portrait
The European Space Agency’s Gaia mission has produced the richest star map of our galaxy to date
[Credit: Satellite: GaiaCopyright: ESA/Gaia/DPAC]

Just as a graph can be made of people with different heights and weights, astronomers compare stars using their luminosities and temperatures. The HRD is a “family portrait” of the stars in the Galaxy, where stars such as the Sun, Altair, Alpha Centauri, Betelgeuse, the north star Polaris and Sirius can be compared. The newly discovered gap cuts diagonally across the HRD and indicates where a crucial internal change occurs in the structures of stars. The gap outlines where stars transition from being larger and mostly convective with a thin radiative layer to being smaller and fully convective.


Radiation and convection are two ways to transfer energy from inside a star to its surface. Radiation transfers energy through space, and convection is the transfer of energy from one place to another by the movement of fluid.


The researchers estimate that stars above the gap contain more than about one-third the mass of the Sun, and those below have less mass. Because different types of stars have different masses, this feature reveals where different types of interior structures are on the HRD. The gap occurs in the middle of the region of “red dwarf” stars, which are much smaller and cooler than the Sun, but compose three of every four stars in the solar neighborhood.


“We were pretty excited to see this result, and it provides us new insights to the structures and evolution of stars,” said Dr. Wei-Chun Jao, first author of the study and a staff astronomer in the Department of Physics and Astronomy at Georgia State.


In 2013, the European Space Agency (ESA) launched the Gaia spacecraft to make a census of the stars in the Milky Way Galaxy and to create a three-dimensional map. In April 2018, the ESA released results of this mission, revealing an unprecedented map of more than one billion stars in the Galaxy, a 10,000-fold increase in the number of stars with accurate distances. The research team led by Georgia State plotted nearly 250,000 of the closest stars in the Gaia data on the HRD to reveal the gap. Georgia State’s researchers have studied the distances to nearby stars for years, which enabled them to interpret the results and notice this thin gap.


The team is now working to pinpoint why the gap is present. Using results from a theoretical computer model that simulates the activity inside the stars, it appears the gap is caused by a slight shrinking in size if a star is convective all the way through.


The findings are published in the journal The Astrophysical Journal Letters.


Author: Latina Emerson | Source: Georgia State University [July 26, 2018]



TANN



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https://xissufotoday.space/2018/07/researchers-discover-thin-gap-on-stellar-family-portrait/

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