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  • richardmitnick 11:18 pm on December 2, 2017 Permalink | Reply
    Tags: , Lightning Bolts Are Churning Out Antimatter All Over Planet Earth, , space.com   

    From SPACE.com: “Lightning Bolts Are Churning Out Antimatter All Over Planet Earth” 

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    SPACE.com

    November 27, 2017
    Rafi Letzter

    1
    Credit: Vasin Lee/Shutterstock

    Particles split in the hot belly of a lightning bolt. Radioactive particles decay in the afterglow. Gamma rays rain down to Earth.

    Teruaki Enoto, a physicist at Kyoto University in Japan, proved for the first time, in a paper published Nov. 23 [Nature], that lightning bolts work as natural particle accelerators. Enoto and his co-authors’ results confirm for the first time speculation dating back to 1925 [Proceedings of the Physical Society of London] about this phenomenon. Back then, scientists suggested that energized, radioactive particles might zip through the booms and flashes of a thunderstorm. Those particles emit energy at precise wavelengths, which Enoto and colleagues are the first to detect.

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  • richardmitnick 2:04 pm on November 8, 2017 Permalink | Reply
    Tags: A rapidly spinning neutron star called a magnetar, A years-long supernova explosion challenges scientist's current understanding of star formation and death, , , , , , For now the event remains a mystery, Las Cumbres Observatory [based] in Goleta California, Pulsation pair instability (PPI) supernova, space.com, The existence of iPTF14hls has far-reaching implications   

    From SPACE.com: “Bizarre 3-Year-Long Supernova Defies Our Understanding of How Stars Die” 

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    SPACE.com

    November 8, 2017
    Harrison Tasoff

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    A massive star reaches the end of its life in an artist’s conception of a supernova. Credit: M. Kornmesser/ESO

    The appearance of a years-long supernova explosion challenges scientist’s current understanding of star formation and death, and work is underway to explain the bizarre phenomenon.

    Stars more than eight times the mass of the sun end their lives in fantastic explosions called supernovas. These are among the most energetic phenomena in the universe. The brightness of a single dying star can briefly rival that of an entire galaxy. Supernovas that form from supermassive stars typically rise quickly to a peak brightness and then fade over the course of around 100 days as the shock wave loses energy.

    In contrast, the newly analyzed supernova iPTF14hls grew dimmer and brighter over the span of more than two years, according to a statement by Las Cumbres Observatory [based] in Goleta, California, which tracked the object. Details of the discovery appeared on Nov. 8 in the journal Nature.

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    Las Cumbres Observatory Global Telescope Network 1-meter telescope node at Cerro Telolo, Chile

    An inconspicuous discovery

    Supernova iPTF14hls was unremarkable when first detected by a partner telescope in San Diego on Sept. 22, 2014. The light spectrum was a textbook example of a Type II-P supernova, the most common type astronomers see, lead author Iair Arcavi, an astronomer at the University of California, Santa Barbara, told Space.com. And the supernova looked like it was already fading, he said.

    The observatory was in the middle of a 7.5-year collaborative survey, so Arcavi focused on more-promising objects. But in February, 2015, Zheng Chuen Wong, a student working for Arcavi that winter, noticed the object had become brighter over the past five months.

    “He showed me the data,” Arcavi said, “and he [asked], ‘Is this normal?’ and I said, ‘Absolutely not. That is very strange. Supernovae don’t do that,'” Arcavi said.

    At first, Arcavi thought it might be a local star in our galaxy, which would appear brighter because it was closer, he said. Many stars are also known to have variable brightness. But the light signature revealed that the object was indeed located in a small, irregular galaxy about 500 million light-years from Earth.

    And the object only got weirder. After 100 days, the supernova looked just 30 days old. Two years later, the supernova’s spectrum still looked the way it would if the explosion were only 60 days old. The supernova recently emerged from behind Earth’s sun, and Arcavi said it’s still bright, after roughly three years. But at one one-hundredth of its peak brightness, the object appears to finally be fading out.

    “Just to be clear, though, there is no existing model or theory that explains all of the observations we have,” said Arcavi. The supernova may fade out; it may grow brighter, or it may suddenly disappear.

    One reason for Arcavi’s uncertainty is that a supernova was seen in the same location in 1954. This means that the event Acavi has been observing, whatever it is, may actually be 60 years running. There’s a 1 to 5 percent chance the two events are unrelated, but that would be even more surprising, said Arcavi. Astronomers have never observed unrelated supernova in the same place decades apart. “We are beyond the cutting-edge of models,” Arcavi said.

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    Supernova iPTF14hls dwarfs typical supernovas in both brightness and longevity. And the event’s dramatic fluctuations pose an exciting challenge for the astronomical community to explain.
    Credit: Credit: S. Wilkinson/LCO

    Beyond cutting edge

    “I’m not sure, and I don’t think anyone else is sure, just what the hell is happening,” astrophysicist Stanford Woosley, at University of California, Santa Cruz, told Space.com. “And yet it happened, and so it begs explanation.”

    Woosley is not affiliated with the study, but he is among the theoreticians working to understand the event. Two hypotheses show promise in explaining it, he said.

    The first involves the famous equation E = mc2. With this formula , Albert Einstein demonstrated that matter and energy are fundamentally interchangeable. Stars burn by converting matter into energy, fusing lighter elements like hydrogen and helium into heavier elements, which build up in the star’s core and also release energy. When a star more than 80 times the mass of the sun reaches a temperature of 1 billion degrees Celsius (1.8 billion degrees Fahrenheit), this energy-matter equivalence produces pairs of electrons and their antiparticle counterparts, positrons, Woosley said. The process robs the star of energy, and so the object shrinks.

    But as this happens, the temperature rises in the star’s core. At 3 billion C (5.4 billion F), oxygen fuses explosively, blowing off massive amounts of material and resetting the cycle. This process repeats until the star reaches a stable mass, explained Woosley. When the front of an ejected shell of material hits the trailing edge of a previous shell, it releases energy as light.

    The star continues to fuse oxygen and the elements of greater masses, up until iron, at which point the reaction fails to release enough energy to keep the star from collapsing in on itself.Eventually, a star like the one that gave rise to iPTF14hls will collapse into a black hole without another explosion, said Woosley.

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    This image depicts a simulated collision between two shells of matter ejected by subsequent pulsation pair instability supernova explosions.
    Credit: Ke-Jung Chen/School of Physics and Astronomy, University of Minnesota

    This phenomenon, called a pulsation pair instability (PPI) supernova, could account for iPTF14hls’ sustained luminosity as well as the object’s varying brightness. This explanation would require the star to have been 105 times the mass of the sun, said Woosley. However, the PPI model cannot account for the tremendous amount of energy iPTF14hls has released. The first explosion of 2014 had more energy than the model predicts for all the explosions combined, said Arcavi.

    What’s more, this phenomenon has yet to be verified observationally. “Stars between 80 and 140 solar masses, which do this kind of thing, have to exist,” said Woosley, “and they have to die, and so, somewhere, this has to be going on.” But no one has seen it yet, he said.

    A magnetic superstorm

    An alternative explanation involves a star 20 to 30 times the mass of Earth’s sun. After a more conventional supernova, such a star could have condensed into a rapidly spinning neutron star, called a magnetar.

    A neutron star packs the mass of 1.5 suns into an object with a diameter about the size of New York City. A neutron star rotating at 1,000 times per second would have more energy than a supernova, according to Woosley. It would also generate a magnetic field 100 trillion to 1 quadrillion times the strength of Earth’s field. As the star spun down over the course of several months, its incredible magnetic field could transfer the star’s rotational energy into the remnants of the supernova that it formed from, releasing light, Woosley explained.

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    An artist depicts a magnetar in the star cluster Westerlund 1. The luminous arcs follow the object’s intense magnetic field. Credit: L. Calçada/ESO

    “It’s like there’s a lighthouse down in the middle of the supernova,” said Woolsey.

    But the magnetar explanation is not perfect, either. It has trouble explaining the dips and peaks in iPTF14hls’ brightness, and the physics behind how such a phenomenon might work is still uncertain, said Woosley.

    As iPTF14hls sheds energy, Arcavi said he hopes to be able to see deeper into the object’s structure. If it is a magnetar, then he expects to see X-rays, previously obscured by the supernova itself, beginning to break through, he said. “Maybe by combining pulsation pair instability with [a magnetar], you can start to explain the supernova,” Arcavi said.

    Keeping busy while keeping watch

    The existence of iPTF14hls has far-reaching implications, the researchers said. At 500 million light-years away, the supernova is still relatively close to Earth, and the universe is practically the same today — in terms of composition and organization —as it was when this event occurred, according to Arcavi. If the event was a PPI supernova, it tells astronomers that stars more than 100 times the mass of the sun — thought to be more prevalent in the early universe — are still forming today.

    The event also had far more hydrogen than researchers expected to see. The explosion in 1954 should have expelled nearly all of the star’s hydrogen, said Arcavi. Astrophysicists will have to revisit their models of supernovas to understand how this can occur, he said.

    The finding has ramifications for the study of galaxies as well. “The energy of the gravity that’s keeping that galaxy together is about the same order of magnitude as the energy that was released in the supernova,” Arcavi said. “So, a few of these in a galaxy could actually unbind the entire galaxy.”

    Arcavi and his team plan to continue monitoring iPTF14hls for at least one to two years. And a suite of international telescopes and observatories will join the effort. Swedish colleagues at the Nordic Optical Telescope, in the Canary Islands, will track the object as it continues to dim beyond what Arcavi’s telescope array can detect. NASA’s Swift spacecraft will look for X-ray emissions, while the Hubble Space Telescope is scheduled to image the location beginning in December, and others will follow, Arcavi said.

    For now, the event remains a mystery.

    “It’s just a puzzle in the sky,” said Woosley. “That’s what we live for, what astronomers love.”

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  • richardmitnick 1:53 pm on November 3, 2017 Permalink | Reply
    Tags: , , , , Heart Nebula IC 1805, Miguel Claro, space.com   

    From SPACE.com: “Star-Speckled Heart Nebula Glows Red in Lovely Deep-Space Photo” 

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    SPACE.com

    November 3, 2017
    Miguel Claro

    Miguel Claro is a professional photographer, author and science communicator based in Lisbon, Portugal, who creates spectacular images of the night sky. As a European Southern Observatory Photo Ambassador and member of The World At Night and the official astrophotographer of the Dark Sky Alqueva Reserve, he specializes in astronomical “Skyscapes” that connect both Earth and night sky. Join Miguel here as he takes us through his photograph, “Heart Nebula: When the Universe Falls in Love.”

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    Heart Nebula IC 1805 captured by astrophotographer Miguel Claro from Cumeada Observatory, headquarters of Dark Sky Alqueva Reserve, Reguengos de Monsaraz, Portugal.
    Credit: Miguel Claro
    The beautiful Heart Nebula, also known as IC 1805, is a bright, red emission nebula with a shape that resembles a human heart.
    This cosmic cloud glows red because it’s filled with ionized hydrogen gas. Darker lanes of interstellar dust create a dark silhouette in the center of the luminous, heart-shaped outline.

    Located about 7,500 light-years from Earth, the Heart Nebula resides in the Perseus Arm of the Milky Way galaxy, in the constellation Cassiopeia. The brightest section, a fish-shaped knot at the cusp of the heart, was discovered before the rest of the Heart Nebula and is separately classified as NGC 896, or the Fishhead Nebula.

    The nebula’s red glow and peculiar shape are a result of intense radiation emanating from a small cluster of stars near the nebula’s core. Known as Melotte 15, this cluster contains a few young, hot and bright-blue supergiant stars nearly 50 times the mass of our sun. These stars are only about 1.5 million years old. (For comparison, our sun is about 4.6 billion years old). Many more dim stars that are only a fraction of our sun’s mass also reside in this cluster.

    Stellar wind, or the stream of charged particles that flows outward from the newborn stars, has sculpted the shape of the Heart Nebula by pushing its clouds of dust and gas outward from the core.

    To capture this image of the Heart Nebula, I used a Takahashi FSQ-106ED refractor telescope with an EM-200 auto-guided mount and a Canon EOS 60Da DSLR astrophotography camera. The camera was programmed to shoot with an ISO setting of 1600 and an exposure time of 210 seconds. The final composite combines 12 frames with a combined exposure time of 42 minutes. Image processing was completed with PixInsight 1.8 and Adobe Photoshop CS6.

    The image was taken from the Cumeada Observatory at the Dark Sky Alqueva Reserve in Reguengos de Monsaraz, Portugal.

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  • richardmitnick 4:21 pm on October 30, 2017 Permalink | Reply
    Tags: , , , , Diary of a Supernova: How (Some) Stars Blow Up, space.com   

    From SPACE.com- “Diary of a Supernova: How (Some) Stars Blow Up” 

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    SPACE.com

    October 30, 2017
    Paul Sutter

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    This supernova remnant was famously discovered in 1604 by Johannes Kepler.
    Credit: X-ray: NASA/CXC/NCSU/M.Burkey et al; Infrared: NASA/JPL-Caltech

    NASA/Chandra Telescope

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA, 4,207 m (13,802 ft) above sea level

    Everything in the universe someday comes to an end. Even stars. Though some might last for trillions of years, steadily sipping away at their hydrogen reserves and converting them to helium, they eventually run out of fuel. And when they do, the results can be pretty spectacular.

    Our own sun will make a mess of the solar system when it enters the last stages of its life in 4 billion years or so. It will swell, turn red (consuming Earth in the process) and cast off its outer layers, giving one last gasp as a planetary nebula before it settles down into post-fusion retirement as a white dwarf.

    The most spectacular deaths, though, are reserved for the most massive stars. Once an object builds up to at least eight times the mass of the sun, interesting games can be played inside the core, with … explosive results.

    To understand how this works, let’s work through a thought experiment. Imagine that the gravity were to increase a tiny bit, then the increased pressure would raise the intensity level of the fusion reactions, which, in turn, would release more energy and thus prevent further collapse of the star. And on the opposite end, if the fusion party were to get just a little bit wilder, it would cause to star to overinflate, lessening the grip of gravity and easing the pressure in the core, cooling things off.

    This balancing act enables a star to last millions, billions and even trillions of years.

    Until it doesn’t.

    The game can be played as long as there’s fuel to keep the lights on. As long as there’s a sufficient supply of hydrogen near the core, the star can keep cranking out the helium and keep resisting the inevitable crush of gravity.

    A crushing force

    I’m not just using a flair of language when I describe the crush of gravity as inevitable. Gravity never stops, never sleeps, never halts. It can be resisted for a long time, but not forever.

    As a star ages, it builds up a core of inert helium. Once the hydrogen supply exhausts itself, there’s nothing to stop the infalling weight of the surrounding material. That is, until the core reaches a scorching temperature of 100 million kelvins (180 million degrees Fahrenheit), at which point helium itself begins to fuse.

    Hooray, the party’s back on! Well, for a while, at least. Helium fusion isn’t as efficient as good ol’ hydrogen, so the reactions happen at an even faster pace to compete with gravity.

    While the “main sequence” of a star’s life may last hundreds of millions of years as it happily burns hydrogen, the helium phase barely lasts a single million.

    The product of helium fusion is carbon and oxygen, and the same game gets played again, but at even higher temperatures and shorter timescales. Once the helium is sucked dry, the core collapses and intensifies to 1 billion K (1.8 billion degrees F), allowing those new elements to get their turn.

    Out of control

    Then, silicon fuses at around 3 billion K (5.4 billion degrees F) in the core, generating iron. Surrounded by plasmatic onion-like layers of oxygen, neon, carbon, helium and hydrogen, the situation at the center starts to get dicey.

    The problem is that, due to its internal nuclear configuration, fusing iron consumes energy rather than releases it. Gravity keeps pressing in, shoving iron atoms together, but there’s no longer anything to oppose its push.

    In less than a day, after millions of years of peaceful nuclear regime changes, the star forms a solid core of iron, and everything goes haywire.

    In a matter of minutes, the intense gravitational pressure slams electrons into the iron nuclei, transforming protons into neutrons. The small, dense neutron core finally has the courage to resist gravity, not by releasing energy but through an effect called degeneracy pressure. You can only pack so many neutrons into a box; eventually, they won’t squeeze any tighter without overwhelming force, and in the first stages of a supernova explosion, even gravity can’t muster enough pull.

    So now you have, say, a couple dozen suns’ worth of material collapsing inward onto an implacable core. Collapse. Bounce. Boom.

    The inside-out inferno

    Except there’s a stall. The shock front, ready to blast out from the core and shred the star to stellar pieces, loses energy and slows down. There’s a bounce but no boom.

    To be perfectly honest, we’re not exactly sure what happens next. Our earliest simulations of this process failed to make stars actually blow up. Since they do blow up in reality, we know we’re missing something.

    For a while, astrophysicists assumed neutrinos might come to the rescue. These ghostly particles hardly ever interact with normal matter, but they’re manufactured in such ridiculously quantities during the “bounce” phase that they can reinvigorate the shock front, filling its sails so it can finish the job.

    But more sophisticated simulations in the past decade have revealed that not even neutrinos can do the trick. There’s plenty of energy to power a supernova blast, but it’s not in the right place at the right time.

    The initial moments of a supernova are a very difficult time to understand, with plasma physics, nuclear reactions, radiation, neutrinos, radiation — a whole textbook’s worth of processes happening all at once. Only further observations and better simulations can fully unlock the final moments of a star’s life. Until then, we can only sit back and enjoy the show.

    See the full article here .

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  • richardmitnick 10:21 am on October 29, 2017 Permalink | Reply
    Tags: , , , , , Dwarf Planets: Science & Facts About the Solar System’s Smaller Worlds, space.com   

    From SPACE.com: “Dwarf Planets: Science & Facts About the Solar System’s Smaller Worlds” 

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    SPACE.com

    October 27, 2017
    SPACE.com Staff
    No writer credit found

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    Dwarf planet Eris Credit: ESO/L. Calçada

    Dwarf planets are worlds that are too small to be considered full-fledged planets, but too large to fall into smaller categories.

    In recent years, there’s been a lot of hubbub about Pluto losing its status as one of the planets of the solar system. Pluto is no longer considered the ninth planet in the series of major planetary objects, but instead is now just one of the many so-called “dwarf planets.” The debate started anew after the New Horizons mission passed by Pluto in 2015, revealing a world of surprising geological complexity. As of 2017, delegates from the mission are trying to get Pluto’s planethood status back.

    Astronomers estimate that there could be as many as 200 dwarf planets in the solar system and the Kuiper Belt. But the differences between planets and dwarf planets may not be obvious at first.

    Kuiper Belt. Minor Planet Center

    Dwarf planets of the solar system

    The International Astronomical Union defines a planet as being in orbit around the sun, has enough gravity to pull its mass into a rounded shape (hydrostatic equilibrium), and has cleared its orbit of other, smaller objects. This last criterion is the point at which planets and dwarf planets differ. A planet’s gravity either attracts or pushes away the smaller bodies that would otherwise intersect its orbit; the gravity of a dwarf planet is not sufficient to make this happen.

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    Meet the dwarf planets of our solar system, Pluto Eris, Haumea, Makemake and Ceres. Credit: Karl Tate, SPACE.com contributor.

    As of 2014, the IAU recognizes five named dwarf planets: Ceres, Pluto, Eris, Haumea, and Makemake. But those aren’t the only ones. Other solar system bodies that are possibly dwarf planets include Sedna and Quaoar, small worlds far beyond Pluto’s orbit, and 2012 VP113, an object that is thought to have one of the most distant orbits found beyond the known edge of our solar system. The object DeeDee could also be a dwarf planet, according to observations made in 2017. According to NASA, scientists think that there may be more than a hundred dwarf planets awaiting discovery.

    However, the debate over the status of dwarf planets, particularly Pluto, remains a hot topic. The primary concern stems from the requirement for a planet to clear out its local neighborhood.

    “In no other branch of science am I familiar with something that absurd,” New Horizons principle investigator Alan Stern told Space.com in 2011. “A river is a river, independent of whether there are other rivers nearby. In science, we call things what they are based on their attributes, not what they’re next to.”

    Is a dwarf planet a separate entity from a planet, or simply another classification? The question may not be settled in the near future.

    Ceres

    Ceres is the earliest known and smallest of the current category of dwarf planets. Sicilian astronomer Giuseppe Piazzi discovered Ceres in 1801 based on the prediction that the gap between Mars and Jupiter contained a missing planet. It is only 590 miles (950 km) in diameter and has a mass of just 0.015 percent that of Earth.

    In fact, Ceres is so small that it is classified as both a dwarf planet and an asteroid, and is often named in scientific literature as one of the largest asteroids in the solar system. Although it makes up approximately a fourth of the mass of the asteroid belt, it is still 14 less massive than Pluto.

    Unlike its asteroid neighbors, Ceres has a nearly round body. The rocky dwarf planet may have water ice beneath its crust. In 2014, the European Space Agency’s Herschel Space Observatory detected water vapor spewing from two regions on Ceres.

    NASA’s robotic Dawn mission arrived at Ceres in 2015. The mission has shown many interesting features on its surface, ranging from various bright spots to a 4-mile-high (6.5-kilometer-high) mountain. (Another mission, the European Space Agency’s Herschel Space Observatory, spotted evidence of water vapor in 2014.)

    NASA/Dawn Spacecraft

    ESA/Herschel spacecraft

    Pluto

    Pluto is the most well known of the dwarf planets. Since its discovery in 1930 and until 2006, it had been classified as the ninth planet from the sun. Pluto’s orbit was so erratic, however, that at times it was closer to the sun than the eighth planet, Neptune. In 2006, with the discovery of several other rocky bodies similar in size or larger than Pluto, the IAU decided to re-classify Pluto as a dwarf planet.

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    This is the most detailed view to date of the entire surface of the dwarf planet Pluto, as constructed from multiple NASA Hubble Space Telescope photographs taken from 2002 to 2003.
    Credit: NASA, ESA, and M. Buie (Southwest Research Institute)

    NASA/ESA Hubble Telescope

    Despite its small size — 0.2 percent the mass of Earth and only 10 percent the mass of Earth’s moon — Pluto’s gravity is enough to capture five moons of its own. The pairing between Pluto and its largest moon, Charon, is known as a binary system, because both objects are orbiting around a central point that is not within the mass of Pluto.

    NASA’s New Horizons mission flew by Pluto in 2015 and revealed a wealth of surprises.

    NASA/New Horizons spacecraft

    This included zones that are bereft of craters (indicating the surface is relatively young), mountains that are likely as high as 11,000 feet (3,500 meters), and even haze above the dwarf planet’s surface.

    Eris

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    https://solarsystem.nasa.gov/planets/eris

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    http://space-engine.wikia.com/wiki/Eris

    When it was first discovered, Eris was thought to be the largest of the dwarf planets, with a mass 27 percent larger than that of Pluto and a diameter of approximately 1,400 to 1,500 miles (2,300 to 2,400 km). It was the discovery of Eris that prompted the IAU to reconsider the definition of a planet. Further observation went on to suggest that the dwarf planet is slightly smaller than Pluto.

    The orbit of Eris is very erratic, crossing that of Pluto and nearly intersecting the orbit of Neptune, but is still more than three times larger than Pluto’s orbit. It takes 557 years for Eris to orbit the sun. At its farthest point from the sun, a point that is also called its aphelion, Eris and its satellite Dysmonia travel far beyond the Kuiper Belt. The surface of Eris is likely nitrogen and methane-rich, but in a thin (1 millimeter) layer across the surface. Some scientists suggest the surface is the condensed atmosphere of Eris, which expands into gas when the dwarf planet is closer to the sun.

    Haumea and Makemake

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    Haumea. Wikipedia

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    An early artist’s interpretation of the dwarf planet Makemake beyond Pluto. Credit: NASA

    Haumea and Makemake are the most recently named dwarf planets in the solar system.

    Haumea is unique because of its ellipsoid shape, only just meeting the hydrostatic equilibrium criteria for dwarf planet status. The elongated shape of the dwarf planet is due to its rapid rotational spin, not a lack of mass, which is about one-third that of Pluto. The cigar-shaped dwarf planet rotates on its axis every four hours, likely a result of a collision. The odd object also hosts a red spot and a layer of crystalline ice. Finally, Haumea is the only object in the Kuiper belt other than Pluto known to host more than one moon.

    A moon was discovered around Makemake in 2016, more than a decade after the dwarf planet itself was found. Its diameter is known to be about two-thirds that of Pluto, and the newly found moon will allow for measurements of its mass. Makemake is also of value to the astronomical community, as it is another reason for the reconsideration of the definition of a planet. Its comparable mass and diameter to Pluto would grant it planet status if Pluto wasn’t also stripped of that title.

    Dwarf planets as ‘plutoids’

    Pluto, Eris, Haumea and Makemake are all known as “plutoids,” unlike the asteroidal dwarf planetoid Ceres. A plutoid is a dwarf planet with an orbit outside that of Neptune. Plutoids are sometimes also referred to as “ice dwarfs” due to their diminutive size and cold surface temperatures.

    The outer planets show evidence of interaction with plutoids. Triton, the largest moon of Neptune, is likely a captured plutoid, and it is even possible that the odd tilt of Uranus on its axis is due to a collision with a plutoid. Similarly to dwarf planets, there are potentially hundreds of plutoid objects in the solar system that have yet to be given official status.

    Additional reporting by Elizabeth Howell and Nola Taylor Redd

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  • richardmitnick 8:28 am on October 29, 2017 Permalink | Reply
    Tags: , , space.com, U Houston, What the Energy Cycles of Other Planets Can Tell Us About Climate Change On Earth   

    From SPACE.com: “What the Energy Cycles of Other Planets Can Tell Us About Climate Change On Earth” 

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    SPACE.com

    October 29, 2017
    Megan Gannon

    1

    The dissipation of total kinetic energy, which indicates how efficient the global atmosphere is as a heat engine, was on the rise between 1979 and 2013. Credit: NASA/University of Houston

    Scientists sometimes think of a planet’s atmosphere as an engine. Potential energy, supplied by heat from a parent star, is converted into kinetic energy, producing winds that swirl around the planet and drive storms.

    This heat engine on Earth has become more efficient because of climate change, and greater efficiency is not necessarily positive in this context. It could mean more dangerous cyclones, hurricanes and storms on Earth, according to a team of planetary scientists who are applying their understanding of the energy cycles of other planets to Earth’s disrupted climate patterns under human-induced climate change.

    “We found the efficiency of converting potential energy into kinetic energy increased over the past 35 years so that there is more kinetic energy available to develop more storms,” said Liming Li, a planetary scientist at the University of Houston.

    LI and his colleagues recently published their research in the journal Nature Communications.

    Climate scientists have been warning that destructive storms will be a greater threat as the planet warms. The new study shows that the atmosphere’s energy cycle could be one way to “diagnose” and understand that storm activity, Li said.

    Li and his colleagues have been analyzing data from NASA’s Cassini mission to the Saturnian system and the Juno mission to Jupiter to study the atmospheres of other worlds in the Solar System. Li has been a participating scientist on on a number of Cassini and Juno’s instruments. His team found that Saturn’s biggest moon, Titan, has a balanced energy budget (just like Earth), and the team investigated how a giant storm on Saturn, tens of thousands of kilometers wide, changed how the planet absorbed solar power.

    Li thought his research about planetary energy for the outer planets could be relevant for Earth, too.

    “I wanted to apply these ideas of planetary energy to our home planet —Earth — to examine if the energy cycle can help us better understand ongoing climate change,” Li said.

    In 1955, the MIT scientist Edward Lorenz — who gave us chaos theory and “the butterfly effect” — came up with a complex formula to explain how potential energy is converted into kinetic energy in the atmosphere. The so-called Lorenz energy cycle is known to influence climate and weather. Past studies looking at variations in the cycle covered short periods of time, only up to 10 years, not long enough to link those observations to well-documented recent changes in the climate, like global warming.

    “Our study is the first to check [the energy cycle’s] long-term temporal variations, which is mainly based on the modern satellite observations,” Li said.

    To calculate potential and kinetic energies, Li and his colleagues looked at data on wind and temperature fields gathered by ground-based observatories and satellites between 1979 and 2013. The researchers found that the total mechanical energy of the global atmosphere was basically the same over time, but the kinetic energy linked to storms appeared to be on the rise.

    “The long-term increasing trend is somehow a surprise,” Li said.

    Li explained that one way to measure the efficiency of a heat engine is to look at the ratio between the incoming energy and dissipating energy. The study also found an increase in the dissipation of energy over time, implying that our atmospheric engine is working with greater efficiency.

    This new research probably won’t directly affect climate-change predictions beyond the more general forecast of more storms in the future, Li said. The study did, however, identify some hotspots where the positive trend in storm energies seems to be particularly strong. Most of those hotspots were in the Southern Hemisphere, notably the storm track around Antarctica. But increased storm energies were also found over the central Pacific Ocean, where scientists have already documented an intensification of tropical cyclones.

    One group of scientists has already calculated the Lorenz energy budget for Mars, and with better observations of other planets, Li said it will be possible to do comparative studies of planetary atmospheres.

    Such studies would provide us a “wide perspective” to understand atmospheric and climate systems, Li said.

    “In particular, the past climate evolution on Mars, in which Mars changed from a warm and wet planet to the current cold and dry world, will help us better understand and predict the climate change on our home planet,” Li added.

    See the full article here .

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  • richardmitnick 8:54 am on December 13, 2016 Permalink | Reply
    Tags: , space.com, Trump, Trump Adds Six More to NASA Transition Team   

    From SPACE.com: “Trump Adds Six More to NASA Transition Team” 

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    SPACE.com

    December 11, 2016
    Brian Berger
    Jeff Foust

    1
    Steve Cook, left, and Aerojet Rocketyne’s Julie Van Kleeck brief reporters on the AR-1 engine at the Space Symposium in Colorado Springs in April. Credit: SpaceNews/Brian Berger

    The transition team for U.S. President-elect Donald Trump added six more people to the NASA landing team Friday, representing a range of viewpoints on topics such as commercial spaceflight and development of heavy-lift launch vehicles.

    Among the new landing team members is Steve Cook, who was in charge of the Ares 1 and Ares 5 rocket programs at NASA’s Marshall Space Flight Center in Huntsville, Alabama, until leaving the agency in 2009 for Huntsville-based Dynetics. The Ares program was canceled under President Barack Obama, but elements of both rockets were folded into NASA’s design for the Space Launch System heavy-lift rocket the agency is building to launch the Orion crew vehicle on deep space missions.

    As a Dynetics corporate vice president, Cook has been closely involved in Aerojet Rocketdyne’s development of the AR-1 engine — a candidate to replace the Russian RD-180 on United Launch Alliance’s next-generation rocket.

    Offering a different perspective on those issues is Greg Autry, an assistant professor of entrepreneurship at the University of Southern California. Autry has written extensively in support of commercial spaceflight despite setbacks like the Falcon 9 pad explosion in September.

    Autry, in an October op-ed that outlines space policy recommendations for the next administration, took a harder line on the SLS. “We will discontinue spending on Space Launch System (SLS), a giant government rocket, lacking both innovation and a mission,” he wrote. “While SLS has consumed the largest single piece of NASA’s budget for years, private sector operators like SpaceX and Blue Origin have leapfrogged it with more efficient, reusable boosters.”

    A third new landing team member, Jack Burns, is a professor at the University of Colorado and senior vice president of the American Astronomical Society. He has been an advocate for lunar exploration, serving as director of the Lunar University Network for Astrophysics Research (LUNAR), a network of universities and NASA centers that studied the use of the moon to support space science research. He was also the chair of the NASA Advisory Council’s science committee in 2009 and 2010.

    The other members announced Friday are:

    Rodney Liesveld, a former senior policy adviser at NASA
    Sandy Magnus, a former NASA astronaut who flew on three missions, including a 4.5-month stay on the International Space Station, and has been executive director of the American Institute of Aeronautics and Astronautics since 2012
    Jeff Waksman, a former research fellow at the U.S. House of Representatives

    The NASA landing team is led by Chris Shank, who worked for House Science Committee Chairman Lamar Smith (R-Texas) until last week. Shank worked for NASA from 2005 to 2009, during the tenure of administrator Mike Griffin.

    Shank, formally named to the landing team Nov. 29, has already been meeting with NASA officials about transition issues. “We’ve had a great couple of days with Chris,” said NASA Associate Administrator Robert Lightfoot at a Dec. 9 Space Transportation Association luncheon here. “He’s just starting the meetings with us, mostly at this point catching up on where we are on items. He’s asking a lot of questions and we’re working with him pretty well.”

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  • richardmitnick 8:43 am on December 13, 2016 Permalink | Reply
    Tags: , , Harvard's 'Computers': The Women Who Measured the Stars, space.com   

    From SPACE.com: “Harvard’s ‘Computers’: The Women Who Measured the Stars” 

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    SPACE.com

    November 9, 2016 [Just appeared in social media.]
    Elizabeth Howell

    1

    Edward Charles Pickering, left, director of the Harvard College Observatory, hired women to analyze the images. Credit: Harvard-Smithsonian Center for Astrophysics

    Before modern devices such as laptops and mobile phones were invented, a “computer” was a person who did calculations. At the Harvard College Observatory, between the late 19th century and early 20thcentury, several dozen women were “computers” who helped lay out some of the fundamental assumptions of astronomy.

    Their job was to look over photographic plates of the night sky and compare the positions of stars between one plate and another. The computers were mainly hired by Edward Charles Pickering, who was director of the observatory from 1877 to 1918. According to Smithsonian magazine, Pickering expanded astrophotography shortly after the new plate technology was made easily available. He was initially caught short, however, when the number of plates produced exceeded the number of people he had on staff to analyze the images.

    Because looking at plates for hours on end was considered boring and unspecialized work, Pickering turned to women to perform the duties. At the time, women were rarely employed outside of the home and were believed to be best suited to managing households. While Pickering’s employment was a jump forward for these women, they remained mainly in clerical roles – showing that women’s status in astronomy had a long way to go in the early 20th century.

    Tough work

    Harvard’s first female computers began work around 1875, although the date is not fixed precisely in a timeline from Harvard’s photographic plate website. “Before then, women, like Eliza Quincy, daughter of founder Josiah Quincy, were only given volunteer status as observers, though several women had applied to work as student assistants,” Harvard wrote. “The first women computers hired [were] R.T. Rogers, R.G. Saunders and Anna Winlock.”

    The women worked full days for six days a week, being paid between 25 cents and 50 cents an hour. This was far less than what a man would have been paid, and in some cases the women hired were not specialists in astronomy. All told, a few dozen women (reported as anywhere between 40 and 80) were hired over the decades and were informally known as “Pickering’s Harem” – a term that today would be considered derogatory.

    In other ways, however, Pickering helped to pioneer modern astronomy. At the time, most observations were done mainly by humans looking through telescopes. Pickering, the Smithsonian wrote, believed that the human eye would get tired over time and may not make accurate measurements. Photographs would provide the opportunity to look at swatches of the sky repeatedly, and could help establish such fundamentals such as which stars were brighter than other ones.

    One of the first computers was Pickering’s maid (and a former teacher), according to the American Museum of Natural History. Williamina Fleming is today best known for finding the Horsehead Nebula and also for classifying the stars depending on their temperature. Thanks to her, the first Draper Catalogue of Stellar Spectra was published in 1890 showing the brightness, star type and position of more than 10,000 stars, according to Harvard.

    Some of the women were specialists, however, such as Annie Jump Cannon. She had a college background in physics and astronomy. Among her contributions was creating the stellar classification system still used today. From hottest to coolest types of stars, the system uses seven letters to organize stars into groups: O, B, A, F, G, K, M. The sun is considered a G star, while M stars are considered red dwarfs and O stars considered blue giants. Cannon created a phrase to make the system easy to remember: “Oh! Be A Fine Girl – Kiss Me!”

    Henrietta Swan Leavitt also had studied astronomy at Harvard, and was hired in 1907 to look at variable stars. According to Harvard, she commonly would place one photographic plate on top of another to see how the brightness in certain stars changed between exposures. She found roughly 2,400 variable stars, and also discovered Cepheid variables. These are stars that have a consistent luminosity, which makes them handy “measuring sticks” to figure out the universe’s expanse.

    2

    Annie Jump Cannon examines a photographic plates of the night sky. She created the stellar classification system still used today. Credit: Harvard-Smithsonian Center for Astrophysics


    Legacy of the Harvard computers

    Leavitt’s use of Cepheid variables ended up being highly useful for Edwin Hubble, who used them in 1924 to establish that the Andromeda Galaxy (more officially known as M31) is actually a galaxy of its own some 2.5 million light-years outside of the Milky Way. Five years later, he published work showing that the universe is expanding, based in part on observations that certain stars were “redshifting” (moving farther away from us, which stretches their light spectrum closer to red.)

    Although not a “computer,” Cecilia Payne-Gaposchkin achieved a noteworthy feat in 1925: she was the first person to get a doctorate in astronomy from Harvard, although her degree was officially issued from Harvard’s affiliate female institution, Radcliffe College, Harvard wrote. (Women were accepted into Harvard only in 1977).

    Payne-Gaposchkin discovered that the sun’s atmosphere is mostly hydrogen, which went against the established thinking of the time that the sun and the Earth shared a similar composition. Payne-Gaposchkin went on to become the first female full professor in Harvard’s faculty of arts and science, then the first female chair at Harvard – in astronomy.

    Pickering appointed Cannon curator of astronomical photographs in 1911, although the Harvard president of the time wouldn’t let her be put in the staff catalog. Her appointment was finally made official in 1938. She won multiple awards for her work before retiring in 1940. She died in 1941.

    The photography plate collection program at Harvard continued until 1992, except for a shutdown for a few years in the 1950s known as the “Menzel Gap” (after its director at the time, who stopped it due to budgetary concerns). By the 1990s, photographic plates were rapidly being supplanted by more advanced technologies, such as the CCDs that are commonly used in digital cameras today. The plate archive, however, remains available for astronomical research and is also being digitized.

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  • richardmitnick 8:02 am on December 4, 2016 Permalink | Reply
    Tags: , , , space.com   

    From SPACE.com: “Sun Storm May Have Caused Flare-Up of Rosetta’s Comet” 

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    SPACE.com

    December 2, 2016
    Nola Taylor Redd

    1
    The ESA/NASA Solar and Heliospheric Observatory spacecraft captured this image of a coronal mass ejection erupting on the sun on Sept. 30, 2015.
    Credit: ESA/NASA/SOHO

    ESA/NASA SOHO
    ESA/NASA SOHO

    Material from the sun may have caused Comet 67P/Churyumov-Gerasimenko to flare up nearly 100 times brighter than average in some parts of the visual spectrum, new research reports.

    At about the same time that charged solar particles slammed into Comet 67P, the European Space Agency’s (ESA) Rosetta spacecraft observed that the icy wanderer dramatically brightened. Initially, scientists assumed that unusual effect came from jets of material within the comet. However, newly released observations of 67P suggest that a burst of charged particles from the sun, known as a coronal mass ejection (CME), could have caused the change.

    “The [brightening] was characterized by a substantial increase in the hydrogen, carbon and oxygen emission lines that increased by roughly 100 times their average brightness on the night of Oct. 5 and 6, 2015,” John Noonan told Space.com. Noonan, who just completed his undergraduate degree at the University of Colorado at Boulder, presented the research at the Division for Planetary Sciences meeting in Pasadena, California, in October.

    After reading a report of a CME that hit 67P at the same time, Noonan realized that the increased emissions from water, carbon dioxide and molecular oxygen observed by Rosetta’s R-Alice instrument could all be explained by the collision of the comet with material jettisoned from the sun.

    “This doesn’t yet rule out that an outburst could have happened, but it looks possible that all of the emissions could have been caused by the CME impact,” Noonan said.

    2
    A simulation reveals how the plasma of the solar wind should interact with Comet 67P/C-G. Credit: Modelling and simulation: Technische Universität Braunschweig and Deutsches Zentrum für Luft- und Raumfahrt; Visualisation: Zuse-Institut Berlin

    Colliding particles

    Rosetta entered orbit around Comet 67P in August 2014, making detailed observations until the probe deliberately crashed into the icy body at the end of its mission in September 2016.

    So Rosetta was tagging along when Comet 67P made its closest pass to the sun in August 2015. (Such “perihelion passages” occur once every 6.45 years — the time it takes the icy object to circle the sun.)

    As 67P neared the sun, newly warmed jets began to release gas from the surface, building up the cloud of debris around the nucleus known as the coma. Jets continued to spout throughout Rosetta’s observations as different regions of the comet rotated into sunlight. Such spouts were initially credited with the extreme brightening that took place in October 2015.

    In addition to warming the comet, the sun also interacted with it through its solar wind, the constant rush of charged particles streaming into space in all directions. Occasionally, the sun also blows off the collections of plasma and charged particles known as CMEs. When CMEs collide with Earth, they can interact with the planet’s magnetic field to create dazzling auroral displays; this interaction can also damage power grids and satellites.

    Niklas Edberg, a scientist on the Rosetta Plasma Consortium Ion and Electron Spectrometer instrument on the spacecraft, and his colleagues recently reported that RPC/IES observed a CME impact on Rosetta at the same time as the bizarre brightening. The ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft detected the CME as it left the sun on Sept. 30, 2015.

    According to Edberg, the CME compressed the plasma material around the comet. Because Rosetta was orbiting within the coma, the probe hadn’t sampled any material streaming from the solar wind since the previous April, and wasn’t expected to do so for several more months. When the CME slammed into the comet, however, the coma was compressed and Rosetta briefly tasted part of the solar wind once again.

    “This suggests that the plasma environment had been compressed significantly, such that the solar wind ions could briefly reach the detector, and provides further evidence that these signatures in the cometary plasma environment are indeed caused by a solar wind event, such as a CME,” Edberg and his team wrote in their study, which was published in the journal Monthly Notices of the Royal Astronomical Society in September 2016.

    Forces at play

    For Noonan, the realization that a CME had impacted the comet at the same time of its unusual brightening had an illuminating effect.

    “I read this [Edberg et al.] paper and realized that the substantial increase in electron density could account for the increased emissions from the coma that R-Alice observed, and set about testing what the density of the coma’s water, carbon dioxide and molecular oxygen components would have to be to match what we saw,” Noonan said.

    Charged particles from the CME may have excited cometary material, causing it to release photons, he added. Some of the observed changes could be created only by interacting electrons, causing what Noonan called “unique fingerprints” that let the scientists know electrons were impacting the material. Of special importance was the transition of oxygen line in the spectra, a change that can only be caused by electrons.

    “During the course of the CME, we saw this line increase in strength by roughly hundredfold,” Noonan said.

    The charged particles were unlikely to have come from the solar wind, which Noonan said would be blocked from ever penetrating this deep.

    While CMEs have been observed around other comets, they have only been viewed remotely. From such great distances, only large-scale changes in the comets’ comas and tails could be observed, Edberg said. Over the course of its two-year mission at Comet 67P, Rosetta’s close orbit allowed it to observe other CMEs interacting with the comet, but Noonan said none were as noticeable as the event of Oct. 5-6, 2015.

    “Prior to Rosetta, these electron impact emissions had never been observed around a comet, and it was these emissions that gave away that the CME might be a factor in causing them,” Noonan said.

    He cautioned that it isn’t a given that the influx of charged particles caused the bizarre brightening, which still could be caused by the jets of material.

    “At this point, we are still working to understand exactly what was the cause to see if it was the CME, and outburst, or both, that caused the emission,” Noonan said.

    Given the timing of the impact, however, it is unlikely that the flare-up was the result of gas released by jets alone.

    “There are more forces at play than just a higher density of gas,” Noonan said.

    See the full article here .

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  • richardmitnick 12:11 pm on November 30, 2016 Permalink | Reply
    Tags: , , , NIHAO, space.com,   

    From SPACE.com: “Ultra-Diffuse Ghost Galaxies Float Among Us” 

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    SPACE.com

    November 30, 2016
    Sarah Lewin

    1

    Ultra-diffuse galaxies are as faint as dwarf galaxies, but spread over an area the size of the Milky Way — with about 1/1000th the number of stars. A new simulation suggests many supernovas at the beginning of a galaxy’s life can push the stars and dark matter outward to a great size. Two simulated ultra-diffuse galaxies are pictured here on top of a Hubble Space Telescope image of background galaxies.
    Credit: Arianna Di Cintio, Chris Brook, NIHAO simulations and Hubble Space Telescope

    Like ghosts, ultra-diffuse galaxies often float undetected in the night sky — stretching the size of the Milky Way, but containing only a dwarf galaxy’s worth of stars. Now, a new simulation suggests their explosive origins, and hints that there may be many more than seen so far.

    Researchers uncovered the first ultra-diffuse galaxy in 2015, and were puzzled by how the faint galaxy came to have such a large size with so few stars. Since then, they’ve spotted many more with the most sensitive telescopes, mostly in large clusters of many galaxies. But this new research suggests that internal dynamics in a forming galaxy, rather than processes happening within clusters, can blow a dwarf up to enormous, spread-out size — and thus they may pepper the universe even far from large clusters, hiding in plain sight because of their faintness.

    2
    The ultra-diffuse galaxy Dragonfly 17, shown in comparison to the large Andromeda galaxy and the elliptical dwarf galaxy NGC 205.
    Credit: Schoening/Harvey/van Dokkum/Hubble Space Telescope

    An international collaboration called NIHAO — the Numerical Investigation of a Hundred Astronomical Objects — simulated the formation of 100 galaxies in extreme detail, tracking the way gases, forming stars and dark matter interacted within the systems. Within that 100, they found some that matched the profile of the newly discovered ultra-diffuse galaxies. So they worked backward to discern what had caused them — not big galaxies failing and growing faint, but dwarf galaxies stretched to an extraordinary size.

    “Once stars explode supernovae, they release a lot of energy into the surrounding gas, and this gas can be expelled really, really fast,” Arianna di Cintio, a researcher at University of Copenhagen’s DARK Cosmology Center and lead author on the new work, told Space.com. If dwarf galaxies experience enough of these supernovas early on in their lives, she said, the galaxy can balloon outwards, borne on the outflows of gas.

    “Basically, the dark-matter particles start flying outwards from the center of the galaxy, and this process happens for the stars as well,” di Cintio said. “At the end of the day, you form a galaxy which has few stars, so it’s a dwarf galaxy, but the stars have spread over a large, large surface — something similar to the Milky Way.”

    Thus, the galaxies’ few million stars puff up to fill a space that could ordinarily host about 1,000 times that number.

    It’s easier to find ultra-diffuse galaxies in big galaxy clusters because that’s where the most powerful telescopes set their sights — for instance, the National Astronomical Observatory of Japan’s Subaru telescope found 854 of them in the Coma Cluster, according to a statement by the university’s Niels Bohr Institute.

    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA
    NAOJ Subaru Telescope interior
    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA

    Just a few have been found so far floating on their own, di Cintio said.

    The fact that the simulation created these familiar — albeit mysterious — structures is “a very, very nice confirmation of what we think is there — the current cosmological model,” di Cintio said. “This effect of expansion of dark matter and stars, we knew that it existed for a few years, [but] no one connected it yet to ultra-diffuse galaxies because they weren’t observed yet.”

    3
    Some of the 854 ultra-diffuse galaxies found by the Subaru Telescope in the Coma galaxy cluster, about 300 million light-years away. Three hundred and thirty-two of them are Milky Way-size. Credit: NAOJ

    Di Cintio said the next steps are to try and verify more ultra-diffuse galaxies living on their own, outside of big clusters, and to measure their mass — potentially through gravitational lensing — to help verify that they’re really dwarf-galaxy-mass. In general, further research will help researchers discover extremely faint, low-surface-brightness galaxies that may lurk in our telescopes’ fields of view.

    “So far, we were blind, in a certain sense, to these low-surface-brightness and ultra-diffuse galaxies,” di Cintio said. “We may be looking around and finding thousands of galaxies that we didn’t even think about yet.”

    The new work was detailed Nov. 29 in the journal Monthly Notices of the Royal Astronomical Society.

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