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  • richardmitnick 10:16 pm on July 22, 2019 Permalink | Reply
    Tags: "10 billion years ago the Milky Way ate a smaller galaxy dubbed Gaia-Enceladus", , , , , , , NASA ESA Hubble   

    From COSMOS Magazine: “10 billion years ago, the Milky Way ate a smaller galaxy dubbed Gaia-Enceladus” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    23 July 2019
    Barry Keily

    1
    Artist’s impression of the merger between the Gaia-Enceladus galaxy and the Milky Way. NASA/ESA/Hubble, CC BY-SA 3.0 IGO

    NASA/ESA Hubble Telescope

    The Milky Way achieved its present form about 10 billion years ago when it merged with a smaller, neighbouring galaxy, new observations and modelling show.

    Researchers led by astrophysicist Carme Gallar of the Universidad de La Laguna in Spain took advantage of measurements taken by the European Space Agency’s Gaia space observatory, which was launched in 2013 for the dedicated purpose of mapping the positions of stars with unprecedented accuracy.

    ESA/GAIA satellite

    They took the new data and subjected it to the two most commonly used techniques for estimating the age of stars – comparison with existing stellar models and what is known as colour-magnitude diagram fitting.

    The approach was applied to Gaia measurements for the galaxy’s two outer rings of stars – known as the blue and red haloes – and what astronomers call its thick central disc.

    The results showed that the stars in the haloes were all more ancient than those in the disc, with those in the former category all exceeding 10 billion years old.

    MIlky Way Galaxy NASA/JPL-Caltech /ESO R. Hurt

    The sharp age difference, the researchers say, confirms and, for the first time, accurately dates a titanic encounter between the progenitor of the Milky Way and a neighbouring, smaller galaxy, dubbed Gaia-Enceladus.

    The different colours of the two haloes are an indication of the iron content of their respective stars. Red stars contain more of it than blue ones. Colour also often indicates great age. Until now, thus, astronomers assumed that the Milky Way’s blue halo was younger than its red one.

    Gallar and colleagues used Gaia data to show that this is not the case. Their modelling reveals that the red and blue haloes contain stars of identical age, and that each region started and ceased star production at about the same time.

    The difference in iron content, the researchers say, is a function of a galaxy size – more massive galaxies contain larger amounts of metal than smaller ones. Thus, they write, the result “means that the stars in the red sequence of the halo, being more metal-rich, must have formed in a galaxy that was more massive than the one where the stars in the blue sequence were formed.”

    The blue halo, they say, represents the remnants of Gaia-Enceladus – a galaxy they estimate to have been around a quarter of the size of the proto Milky Way.

    The research is published in the journal Nature Astronomy.

    See the full article here .


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  • richardmitnick 8:38 am on July 16, 2019 Permalink | Reply
    Tags: , , , , , NASA ESA Hubble,   

    From NASA/ESA Hubble Telescope: “New Hubble Constant Measurement Adds to Mystery of Universe’s Expansion Rate” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    July 16, 2019

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Louise Lerner
    University of Chicago, Chicago, Illinois
    773-702-8366
    louise@uchicago.edu

    1
    About This Image

    These galaxies are selected from a Hubble Space Telescope program to measure the expansion rate of the universe, called the Hubble constant. The value is calculated by comparing the galaxies’ distances to the apparent rate of recession away from Earth (due to the relativistic effects of expanding space).

    By comparing the apparent brightnesses of the galaxies’ red giant stars with nearby red giants, whose distances were measured with other methods, astronomers are able to determine how far away each of the host galaxies are. This is possible because red giants are reliable milepost markers because they all reach the same peak brightness in their late evolution. And, this can be used as a “standard candle” to calculate distance. Hubble’s exquisite sharpness and sensitivity allowed for red giants to be found in the stellar halos of the host galaxies.

    The red giants were searched for in the halos of the galaxies. The center row shows Hubble’s full field of view. The bottom row zooms even tighter into the Hubble fields. The red giants are identified by yellow circles. Credits: NASA, ESA, W. Freedman (University of Chicago), ESO, and the Digitized Sky Survey

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    About This Image: Credits: NASA, ESA, W. Freedman (University of Chicago), ESO, and the Digitized Sky Survey

    ________________________________________________________

    3

    Red Giant Stars Used as Milepost Markers

    Astronomers have made a new measurement of how fast the universe is expanding, using an entirely different kind of star than previous endeavors. The revised measurement, which comes from NASA’s Hubble Space Telescope, falls in the center of a hotly debated question in astrophysics that may lead to a new interpretation of the universe’s fundamental properties.

    Scientists have known for almost a century that the universe is expanding, meaning the distance between galaxies across the universe is becoming ever more vast every second. But exactly how fast space is stretching, a value known as the Hubble constant, has remained stubbornly elusive.

    Now, University of Chicago professor Wendy Freedman and colleagues have a new measurement for the rate of expansion in the modern universe, suggesting the space between galaxies is stretching faster than scientists would expect. Freedman’s is one of several recent studies that point to a nagging discrepancy between modern expansion measurements and predictions based on the universe as it was more than 13 billion years ago, as measured by the European Space Agency’s Planck satellite.

    ESA/Planck 2009 to 2013

    As more research points to a discrepancy between predictions and observations, scientists are considering whether they may need to come up with a new model for the underlying physics of the universe in order to explain it.

    “The Hubble constant is the cosmological parameter that sets the absolute scale, size and age of the universe; it is one of the most direct ways we have of quantifying how the universe evolves,” said Freedman. “The discrepancy that we saw before has not gone away, but this new evidence suggests that the jury is still out on whether there is an immediate and compelling reason to believe that there is something fundamentally flawed in our current model of the universe.”

    In a new paper accepted for publication in The Astrophysical Journal, Freedman and her team announced a new measurement of the Hubble constant using a kind of star known as a red giant. Their new observations, made using Hubble, indicate that the expansion rate for the nearby universe is just under 70 kilometers per second per megaparsec (km/sec/Mpc). One parsec is equivalent to 3.26 light-years distance.

    This measurement is slightly smaller than the value of 74 km/sec/Mpc recently reported by the Hubble SH0ES (Supernovae H0 for the Equation of State) team using Cepheid variables, which are stars that pulse at regular intervals that correspond to their peak brightness. This team, led by Adam Riess of the Johns Hopkins University and Space Telescope Science Institute, Baltimore, Maryland, recently reported refining their observations to the highest precision to date for their Cepheid distance measurement technique.

    How to Measure Expansion

    A central challenge in measuring the universe’s expansion rate is that it is very difficult to accurately calculate distances to distant objects.

    In 2001, Freedman led a team that used distant stars to make a landmark measurement of the Hubble constant. The Hubble Space Telescope Key Project team measured the value using Cepheid variables as distance markers. Their program concluded that the value of the Hubble constant for our universe was 72 km/sec/Mpc.

    But more recently, scientists took a very different approach: building a model based on the rippling structure of light left over from the big bang, which is called the Cosmic Microwave Background [CMB].

    CMB per ESA/Planck

    The Planck measurements allow scientists to predict how the early universe would likely have evolved into the expansion rate astronomers can measure today. Scientists calculated a value of 67.4 km/sec/Mpc, in significant disagreement with the rate of 74.0 km/sec/Mpc measured with Cepheid stars.

    Astronomers have looked for anything that might be causing the mismatch. “Naturally, questions arise as to whether the discrepancy is coming from some aspect that astronomers don’t yet understand about the stars we’re measuring, or whether our cosmological model of the universe is still incomplete,” Freedman said. “Or maybe both need to be improved upon.”

    Freedman’s team sought to check their results by establishing a new and entirely independent path to the Hubble constant using an entirely different kind of star.

    Certain stars end their lives as a very luminous kind of star called a red giant, a stage of evolution that our own Sun will experience billions of years from now. At a certain point, the star undergoes a catastrophic event called a helium flash, in which the temperature rises to about 100 million degrees and the structure of the star is rearranged, which ultimately dramatically decreases its luminosity. Astronomers can measure the apparent brightness of the red giant stars at this stage in different galaxies, and they can use this as a way to tell their distance.

    The Hubble constant is calculated by comparing distance values to the apparent recessional velocity of the target galaxies — that is, how fast galaxies seem to be moving away. The team’s calculations give a Hubble constant of 69.8 km/sec/Mpc — straddling the values derived by the Planck and Riess teams.

    “Our initial thought was that if there’s a problem to be resolved between the Cepheids and the Cosmic Microwave Background, then the red giant method can be the tie-breaker,” said Freedman.

    But the results do not appear to strongly favor one answer over the other say the researchers, although they align more closely with the Planck results.

    NASA’s upcoming mission, the Wide Field Infrared Survey Telescope (WFIRST), scheduled to launch in the mid-2020s, will enable astronomers to better explore the value of the Hubble constant across cosmic time.

    NASA/WFIRST

    WFIRST, with its Hubble-like resolution and 100 times greater view of the sky, will provide a wealth of new Type Ia supernovae, Cepheid variables, and red giant stars to fundamentally improve distance measurements to galaxies near and far.

    More links at the full article.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:27 am on July 11, 2019 Permalink | Reply
    Tags: , , , Black Hole science, , NASA ESA Hubble, Spiral galaxy NGC 3147   

    From NASA/ESA Hubble Telescope: “Hubble Uncovers Black Hole Disk that Shouldn’t Exist” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    July 11, 2019

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Stefano Bianchi
    Università degli Studi Roma Tre, Rome, Italy
    bianchi@fis.uniroma3.it

    Marco Chiaberge
    Space Telescope Science Institute, Baltimore, Maryland
    marcoc@stsci.edu

    1
    NGC 3147 spiral galaxy

    2
    Central Black Hole in NGC 3147, with artist’s illustration

    4
    Compass image of NGC 3147

    __________________________________________________________________________________________
    Hubble Offers Peek at Material Swirling Close to a Black Hole

    Astronomers are always tickled when they find something they didn’t expect to be there. Peering deep into the heart of the majestic spiral galaxy NGC 3147, researchers uncovered a swirling gas disk precariously close to a black hole weighing about 250 million times the mass of our Sun. The surprise is that they thought the black hole was so malnourished, it shouldn’t have such a structure around it. It’s basically a “Mini-Me” version of more powerful disks seen in very active galaxies.

    What’s especially intriguing is that the disk is so deeply embedded in the black hole’s intense gravitational field, its light is being stretched and intensified by the black hole’s powerful grasp. It’s a unique, real-world demonstration of Einstein’s laws of relativity, formulated a century ago.

    Hubble clocked material whirling around the black hole as moving at more than 10% of the speed of light. And, the gas astronomers measured is so entrenched in the gravitational well that light is struggling to climb out, and therefore appears stretched to redder wavelengths.
    __________________________________________________________________________________________

    As if black holes weren’t mysterious enough, astronomers using NASA’s Hubble Space Telescope have found an unexpected thin disk of material furiously whirling around a supermassive black hole at the heart of the magnificent spiral galaxy NGC 3147, located 130 million light-years away.

    The conundrum is that the disk shouldn’t be there, based on current astronomical theories. However, the unexpected presence of a disk so close to a black hole offers a unique opportunity to test Albert Einstein’s theories of relativity. General relativity describes gravity as the curvature of space and special relativity describes the relationship between time and space.

    “We’ve never seen the effects of both general and special relativity in visible light with this much clarity,” said Marco Chiaberge of the European Space Agency, and the Space Telescope Science Institute and Johns Hopkins University, both in Baltimore, Maryland, a member of the team that conducted the Hubble study.

    “This is an intriguing peek at a disk very close to a black hole, so close that the velocities and the intensity of the gravitational pull are affecting how the photons of light look,” added the study’s first author, Stefano Bianchi of Università degli Studi Roma Tre, in Rome, Italy. “We cannot understand the data unless we include the theories of relativity.”

    Black holes in certain types of galaxies like NGC 3147 are malnourished because there is not enough gravitationally captured material to feed them regularly. So, the thin haze of infalling material puffs up like a donut rather than flattening out in a pancake-shaped disk. Therefore, it is very puzzling why there is a thin disk encircling a starving black hole in NGC 3147 that mimics much more powerful disks found in extremely active galaxies with engorged, monster black holes.

    “We thought this was the best candidate to confirm that below certain luminosities, the accretion disk doesn’t exist anymore,” explained Ari Laor of the Technion-Israel Institute of Technology located in Haifa, Israel. “What we saw was something completely unexpected. We found gas in motion producing features we can explain only as being produced by material rotating in a thin disk very close to the black hole.”

    The astronomers initially selected this galaxy to validate accepted models about lower-luminosity active galaxies—those with black holes that are on a meager diet of material. Models predict that an accretion disk forms when ample amounts of gas are trapped by a black hole’s strong gravitational pull. This infalling matter emits lots of light, producing a brilliant beacon called a quasar, in the case of the most well-fed black holes. Once less material is pulled into the disk, it begins to break down, becomes fainter, and changes structure.

    “The type of disk we see is a scaled-down quasar that we did not expect to exist,” Bianchi said. “It’s the same type of disk we see in objects that are 1,000 or even 100,000 times more luminous. The predictions of current models for gas dynamics in very faint active galaxies clearly failed.”

    The disk is so deeply embedded in the black hole’s intense gravitational field that the light from the gas disk is modified, according to Einstein’s theories of relativity, giving astronomers a unique look at the dynamic processes close to a black hole.

    Hubble clocked material whirling around the black hole as moving at more than 10% of the speed of light. At those extreme velocities, the gas appears to brighten as it travels toward Earth on one side, and dims as it speeds away from our planet on the other side (an effect called relativistic beaming). Hubble’s observations also show that the gas is so entrenched in the gravitational well the light is struggling to climb out, and therefore appears stretched to redder wavelengths. The black hole’s mass is around 250 million Suns.

    The researchers used Hubble’s Space Telescope Imaging Spectrograph (STIS) to observe matter swirling deep inside the disk. A spectrograph is a diagnostic tool that divides light from an object into its many individual wavelengths to determine its speed, temperature, and other characteristics at a very high precision. The astronomers needed STIS’s sharp resolution to isolate the faint light from the black-hole region and block out contaminating starlight.

    “Without Hubble, we wouldn’t have been able to see this because the black-hole region has a low luminosity,” Chiaberge said. “The luminosities of the stars in the galaxy outshine anything in the nucleus. So if you observe it from the ground, you’re dominated by the brightness of the stars, which drowns the feeble emission from the nucleus.”

    The team hopes to use Hubble to hunt for other very compact disks around low-wattage black holes in similar active galaxies.

    The team’s paper will appear online today in the Monthly Notices of the Royal Astronomical Society.

    The international team of astronomers in this study consists of Stefano Bianchi (Università degli Studi Roma Tre, Rome, Italy); Robert Antonucci (University of California, Santa Barbara, California); Alessandro Capetti (INAF – Osservatorio Astrofisico di Torino, Pino Torinese, Italy); Marco Chiaberge (Space Telescope Science Institute and Johns Hopkins University, Baltimore, Maryland); Ari Laor (Israel Institute of Technology, Haifa, Israel); Loredana Bassani (INAF/IASF Bologna, Italy); Francisco Carrera (CSIC-Universidad de Cantabria, Santander, Spain); Fabio La Franca, Andrea Marinucci, Giorgio Matt, and Riccardo Middei (Università degli Studi Roma Tre, Roma, Italy); and Francesca Panessa (INAF Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy).

    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 Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:43 am on July 2, 2019 Permalink | Reply
    Tags: "Atmosphere of Mid-Size Planet Revealed by Hubble and Spitzer", , , , , Mysterious World Is Unlike Anything Found in Our Solar System., NASA ESA Hubble, , One possible explanation is that the planet formed as a 10-Earth-mass rocky core that then accumulated hydrogen very close to its star rather than migrated in which is the conventional wisdom., Plamet GJ 3470 b, Weighing in at 12.6 Earth masses GJ 3470 b is more massive than Earth but less massive than Neptune   

    From NASA/ESA Hubble Telescope: “Atmosphere of Mid-Size Planet Revealed by Hubble and Spitzer” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    1

    Mysterious World Is Unlike Anything Found in Our Solar System.

    Our solar system contains two major classes of planets. Earth is a rocky terrestrial planet, as are Mercury, Venus, and Mars. At about the distance of the asteroid belt, there is a “frost line” where space is so cold more volatile material, like water, can remain frozen. Out here live the gas giants–Jupiter, Saturn, Uranus, and Neptune–which have bulked up on hydrogen and helium and other volatiles.

    Astronomers are curious about a new class of planet not found in the Solar System. Weighing in at 12.6 Earth masses the planet is more massive than Earth, but less massive than Neptune (hence, intermediate between the rocky and gaseous planets in the Solar System). What’s more, the planet, GJ 3470 b, is so close to its red dwarf star that it completes one orbit in just three days! As odd as it seems, planets in this mass range are likely the most abundant throughout the galaxy, based on surveys by NASA’s Kepler space telescope. But they are not found in our own solar system.

    Astronomers enlisted the combined multi-wavelength capabilities of NASA’s Hubble and Spitzer space telescopes to assemble for the first time a “fingerprint” of the chemical composition of GJ 3470 b’s atmosphere, which turns out to be mostly hydrogen and helium, and surprisingly, largely lacking heavier elements. One possible explanation is that the planet formed as a 10-Earth-mass rocky core that then accumulated hydrogen very close to its star, rather than migrated in which is the conventional wisdom for star-hugging planets.

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Björn Benneke
    University of Montreal, Canada
    bbenneke@astro.umontreal.ca

    2
    About This Image

    Structure of Exoplanet GJ 3470 b

    This artist’s illustration shows the theoretical internal structure of the exoplanet GJ 3470 b. It is unlike any planet found in the Solar System. Weighing in at 12.6 Earth masses the planet is more massive than Earth but less massive than Neptune. Unlike Neptune, which is 3 billion miles from the Sun, GJ 3470 b may have formed very close to its red dwarf star as a dry, rocky object. It then gravitationally pulled in hydrogen and helium gas from a circumstellar disk to build up a thick atmosphere. The disk dissipated many billions of years ago, and the planet stopped growing. The bottom illustration shows the disk as the system may have looked long ago. Observations by NASA’s Hubble and Spitzer space telescopes have chemically analyzed the composition of GJ 3470 b’s very clear and deep atmosphere, yielding clues to the planet’s origin. Many planets of this mass exist in our galaxy.

    Two NASA space telescopes have teamed up to identify, for the first time, the detailed chemical “fingerprint” of a planet between the sizes of Earth and Neptune. No planets like this can be found in our own solar system, but they are common around other stars.

    The planet, Gliese 3470 b (also known as GJ 3470 b), may be a cross between Earth and Neptune, with a large rocky core buried under a deep crushing hydrogen and helium atmosphere. Weighing in at 12.6 Earth masses, the planet is more massive than Earth, but less massive than Neptune (which is more than 17 Earth masses).

    Many similar worlds have been discovered by NASA’s Kepler space telescope, whose mission ended in 2018. In fact, 80% of the planets in our galaxy may fall into this mass range. However, astronomers have never been able to understand the chemical nature of such a planet until now, researchers say.

    By inventorying the contents of GJ 3470 b’s atmosphere, astronomers are able to uncover clues about the planet’s nature and origin.

    “This is a big discovery from the planet formation perspective. The planet orbits very close to the star and is far less massive than Jupiter—318 times Earth’s mass—but has managed to accrete the primordial hydrogen/helium atmosphere that is largely “unpolluted” by heavier elements,” said Björn Benneke of the University of Montreal, Canada. “We don’t have anything like this in the solar system, and that’s what makes it striking.”

    Astronomers enlisted the combined multi-wavelength capabilities NASA’s Hubble and Spitzer space telescopes to do a first-of-a-kind study of GJ 3470 b’s atmosphere.

    NASA/Spitzer Infrared Telescope

    This was accomplished by measuring the absorption of starlight as the planet passed in front of its star (transit) and the loss of reflected light from the planet as it passed behind the star (eclipse).

    Planet transit. NASA/Ames

    All totaled, the space telescopes observed 12 transits and 20 eclipses. The science of analyzing chemical fingerprints based on light is called “spectroscopy.”

    “For the first time we have a spectroscopic signature of such a world,” said Benneke. But he is at a loss for classification: Should it be called a “super-Earth” or “sub-Neptune?” Or perhaps something else?

    Fortuitously, the atmosphere of GJ 3470 b turned out to be mostly clear, with only thin hazes, enabling the scientists to probe deep into the atmosphere.

    “We expected an atmosphere strongly enriched in heavier elements like oxygen and carbon which are forming abundant water vapor and methane gas, similar to what we see on Neptune”, said Benneke. “Instead, we found an atmosphere that is so poor in heavy elements that its composition resembles the hydrogen/helium rich composition of the Sun.”

    Other exoplanets called “hot Jupiters” are thought to form far from their stars, and over time migrate much closer. But this planet seems to have formed just where it is today, says Benneke.

    The most plausible explanation, according to Benneke, is that GJ 3470 b was born precariously close to its red dwarf star, which is about half the mass of our Sun. He hypothesizes that essentially it started out as a dry rock, and rapidly accreted hydrogen from a primordial disk of gas when its star was very young. The disk is called a “protoplanetary disk.”

    “We’re seeing an object that was able to accrete hydrogen from the protoplanetary disk, but didn’t runaway to become a hot Jupiter,” said Benneke. “This is an intriguing regime.”

    One explanation is that the disk dissipated before the planet could bulk up further. “The planet got stuck being a sub-Neptune,” said Benneke.

    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 Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 10:17 am on July 1, 2019 Permalink | Reply
    Tags: , , , , , NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “Hubble Captures the Galaxy’s Biggest Ongoing Stellar Fireworks Show” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    July 01, 2019

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Nathan Smith
    University of Arizona, Tucson, Arizona
    520-621-4513
    nathans@as.arizona.edu

    Jon Morse
    BoldlyGo Institute, New York, New York
    646-380-1813
    jamorse@boldlygo.org

    1

    2
    Compass Image for Eta Carinae
    These images are a composite of separate exposures acquired by the WFC3/UVIS instrument on the Hubble Space Telescope. Several filters were used to sample narrow and wide wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: F280N Green: F336W Red: F658N

    Eta Carinae (Observations in UV Light Uncover Magnesium Embedded in Warm Gas)

    Imagine slow-motion fireworks that started exploding 170 years ago and are still continuing. This type of firework is not launched into Earth’s atmosphere, but rather into space by a doomed super-massive star, called Eta Carinae, the largest member of a double-star system. A new view from NASA’s Hubble Space Telescope, which includes ultraviolet light, shows the star’s hot, expanding gases glowing in red, white, and blue. Eta Carinae resides 7,500 light-years away.

    The celestial outburst takes the shape of a pair of ballooning lobes of dust and gas and other filaments that were blown out from the petulant star. The star may have initially weighed more than 150 Suns. For decades, astronomers have speculated about whether it is on the brink of total destruction.

    The fireworks started in the 1840s when Eta Carinae went through a titanic outburst, called the Great Eruption, making it the second-brightest star visible in the sky for over a decade. Eta Carinae, in fact, was so bright that for a time it became an important navigational star for mariners in the southern seas.

    The star has faded since that eruption and is now barely visible to the unaided eye. But the fireworks aren’t over yet because Eta Carinae still survives. Astronomers have used almost every instrument on Hubble over the past 25 years to study the rambunctious star.

    Using Hubble’s Wide Field Camera 3 to map the ultraviolet-light glow of magnesium embedded in warm gas (shown in blue), astronomers were surprised to discover the gas in places they had not seen it before.

    NASA/ESA Hubble WFC3

    Scientists have long known that the outer material thrown off in the 1840s eruption has been heated by shock waves after crashing into the doomed star’s previously ejected material. In the new images, the team had expected to find light from magnesium coming from the same complicated array of filaments as seen in the glowing nitrogen (shown in red). Instead, a completely new luminous magnesium structure was found in the space between the dusty bipolar bubbles and the outer shock-heated nitrogen-rich filaments.

    “We’ve discovered a large amount of warm gas that was ejected in the Great Eruption but hasn’t yet collided with the other material surrounding Eta Carinae,” explained Nathan Smith of Steward Observatory at the University of Arizona in Tucson, Arizona, lead investigator of the Hubble program. “Most of the emission is located where we expected to find an empty cavity. This extra material is fast, and it ‘ups the ante’ in terms of the total energy for an already powerful stellar blast.”

    The newly revealed gas is important for understanding how the eruption began, because it represents the fast and energetic ejection of material that may have been expelled by the star shortly before the expulsion of the bipolar lobes. Astronomers need more observations to measure exactly how fast the material is moving and when it was ejected.

    The streaks visible in the blue region outside the lower-left lobe are a striking feature in the image. These streaks are created when the star’s light rays poke through the dust clumps scattered along the bubble’s surface. Wherever the ultraviolet light strikes the dense dust, it leaves a long, thin shadow that extends beyond the lobe into the surrounding gas. “The pattern of light and shadow is reminiscent of sunbeams that we see in our atmosphere when sunlight streams past the edge of a cloud, though the physical mechanism creating Eta Carinae’s light is different,” noted team member Jon Morse of BoldlyGo Institute in New York.

    This technique of searching in ultraviolet light for warm gas could be used to study other stars and gaseous nebulas, the researchers say.

    “We had used Hubble for decades to study Eta Carinae in visible and infrared light, and we thought we had a pretty full accounting of its ejected debris. But this new ultraviolet-light image looks astonishingly different, revealing gas we did not see in other visible-light or infrared images,” Smith said. “We’re excited by the prospect that this type of ultraviolet magnesium emission may also expose previously hidden gas in other types of objects that eject material, such as protostars or other dying stars. Only Hubble can take these kinds of pictures.”

    Eta Carinae has had a violent history, prone to chaotic eruptions that blast parts of itself into space like an interstellar geyser. One explanation for the monster star’s antics is that the convulsions were caused by a complex interplay of as many as three stars, all gravitationally bound in one system. In this scenario, the most massive member would have swallowed one of the stars, igniting the massive Great Eruption of the mid-1800s. Evidence for that event lies in the huge, expanding bipolar lobes of hot gas surrounding the system.

    A fortuitous trick of nature also allowed astronomers in a previous Hubble study to analyze the Great Eruption in detail. Some of the light from the eruption took an indirect path to Earth and is just arriving now. The wayward light was heading away from our planet when it bounced off dust clouds lingering far from the turbulent stars and was rerouted to Earth, an effect called a “light echo.”

    The stellar behemoth will eventually reach its fireworks show finale when it explodes as a supernova. This may have already happened, although the geyser of light from such a brilliant blast hasn’t yet reached Earth.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 10:43 am on June 16, 2019 Permalink | Reply
    Tags: , , , , NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “Hubble Observes Tiny Galaxy with Big Heart” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    13 June 2019
    Bethany Downer
    ESA/Hubble, Public Information Officer
    Garching bei München, Germany
    Email: bethany.downer@partner.eso.org

    1
    Nestled within this field of bright foreground stars lies ESO 495-21, a tiny galaxy with a big heart. ESO 495-21 may be just 3000 light-years across, but that is not stopping the galaxy from furiously forming huge numbers of stars. It may also host a supermassive black hole; this is unusual for a galaxy of its size, and may provide intriguing hints as to how galaxies form and evolve.

    2
    Ground-based view of the sky around the galaxy ESO 495-21

    Located about 30 million light-years away in the constellation of Pyxis (The Compass), ESO 495-21 is a dwarf starburst galaxy — this means that it is small in size, but ablaze with rapid bursts of star formation. Starburst galaxies form stars at exceptionally high rates, creating stellar newborns of up to 1000 times faster than the Milky Way.

    Hubble has studied the bursts of activity within ESO 495-21 several times. Notably, the space telescope has explored the galaxy’s multiple super star clusters, very dense regions only a few million years old and packed with massive stars. These spectacular areas can have a huge impact on their host galaxies. Studying them allows astronomers to investigate the earliest stages of their evolution, in a bid to understand how massive stars form and change throughout the Universe.

    As well as hosting the cosmic fireworks that are super star clusters, ESO 495-21 also may harbour a supermassive black hole at its core. Astronomers know that almost every large galaxy hosts such an object at its centre, and, in general, the bigger the galaxy, the more massive the black hole. Our home galaxy, the Milky Way, houses a supermassive black hole, Sagittarius A*, which is over four million times as massive as the Sun. ESO 495-21, also known as Henize 2-10) is a dwarf galaxy, only three percent the size of the Milky Way, and yet there are indications that the black hole at its core is over a million times as massive as the Sun — an extremely unusual scenario.

    This black hole may offer clues as to how black holes and galaxies evolved in the early Universe. The origin of the central supermassive black holes in galaxies is still a matter of debate — do the galaxies form first and then crush material at their centres into black holes, or do pre-existing black holes gather galaxies around them? Do they evolve together — or could the answer be something else entirely?

    With its small size, indistinct shape, and rapid starburst activity, astronomers think ESO 495-21 may be an analogue for some of the first galaxies to have formed in the cosmos. Finding a black hole at the galaxy’s heart is therefore a strong indication that black holes may have formed first, with galaxies later developing and evolving around them.

    The data comprising this image were gathered by two of the instruments aboard the NASA/ESA Hubble Space Telescope: the Advanced Camera for Surveys and already decommissioned Wide Field Planetary Camera 2.

    NASA Hubble Advanced Camera forSurveys

    NASA/Hubble WFPC2. No longer in service.

    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 Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 3:23 pm on June 3, 2019 Permalink | Reply
    Tags: "A Pair of Fledgling Planets Directly Seen Growing Around a Young Star", , , , , NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “A Pair of Fledgling Planets Directly Seen Growing Around a Young Star” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    Jun 3, 2019

    Christine Pulliam
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4366
    cpulliam@stsci.edu

    1
    Gas giants are carving a gap within a planet-forming disk. In order to grow to Jupiter size or larger, a gas giant planet must slurp large quantities of hydrogen and other gases from the disk in which it forms. Astronomers have looked for evidence of this process, but direct observations are challenging because planets become lost in the glare of their star. A team has succeeded in making ground-based observations of two planets accreting matter from a disk. It represents only the second multi-planet system to be directly imaged.

    Astronomers have directly imaged two exoplanets that are gravitationally carving out a wide gap within a planet-forming disk surrounding a young star. While over a dozen exoplanets have been directly imaged, this is only the second multi-planet system to be photographed. (The first was a four-planet system orbiting the star HR 8799.) Unlike HR 8799, though, the planets in this system are still growing by accreting material from the disk.

    “This is the first unambiguous detection of a two-planet system carving a disk gap,” said Julien Girard of the Space Telescope Science Institute in Baltimore, Maryland.

    The host star, known as PDS 70, is located about 370 light-years from Earth. The young 6-million-year-old star is slightly smaller and less massive than our Sun, and is still accreting gas. It is surrounded by a disk of gas and dust that has a large gap extending from about 1.9 to 3.8 billion miles.

    PDS 70 b, the innermost known planet, is located within the disk gap at a distance of about 2 billion miles from its star, similar to the orbit of Uranus in our solar system. The team estimates that it weighs anywhere from 4 to 17 times as much as Jupiter. It was first detected in 2018.

    PDS 70 c, the newly discovered planet, is located near the outer edge of the disk gap at about 3.3 billion miles from the star, similar to Neptune’s distance from our Sun. It is less massive than planet b, weighing between 1 and 10 times as much as Jupiter. The two planetary orbits are near a 2-to-1 resonance, meaning that the inner planet circles the star twice in the time it takes the outer planet to go around once.

    The discovery of these two worlds is significant because it provides direct evidence that forming planets can sweep enough material out of a protoplanetary disk to create an observable gap.

    “With facilities like ALMA, Hubble, or large ground-based optical telescopes with adaptive optics we see disks with rings and gaps all over.

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

    The open question has been, are there planets there? In this case, the answer is yes,” explained Girard.

    The team detected PDS 70 c from the ground, using the MUSE spectrograph on the European Southern Observatory’s Very Large Telescope (VLT).

    ESO MUSE on the VLT on Yepun (UT4)

    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,

    Their new technique relied on the combination of the high spatial resolution provided by the 8-meter telescope equipped with four lasers and the instrument’s medium spectral resolution that allows it to “lock onto” light emitted by hydrogen, which is a sign of gas accretion.

    “This new observing mode was developed to study galaxies and star clusters at higher spatial resolution. But this new mode also makes it suitable for exoplanet imaging, which was not the original science driver for the MUSE instrument,” said Sebastiaan Haffert of Leiden Observatory, lead author on the paper.

    “We were very surprised when we found the second planet,” Haffert added.

    In the future, NASA’s James Webb Space Telescope may be able to study this system and other planet nurseries using a similar spectral technique to narrow in on various wavelengths of light from hydrogen. This would allow scientists to measure the temperature and density of gas within the disk, which would help our understanding of the growth of gas giant planets. The system might also be targeted by the WFIRST mission, which will carry a high-performance coronagraph technology demonstration that can block out the star’s light to reveal fainter light from the surrounding disk and companion planets.

    These results were published in the June 3 issue of Nature Astronomy.

    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 Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:12 am on May 25, 2019 Permalink | Reply
    Tags: , , , , Messier 90, NASA ESA Hubble,   

    From Science Times: “Curious Hubble Discovers A Galaxy Moving Closer To Earth” 

    Science Times

    From Science Times

    May 25, 2019
    Lysette Maurice N. Sandoval

    NASA/ESA Hubble Telescope

    1
    Messier 90. by Sloan Digital Sky Survey.

    The Hubble continues to spy on the Earth’s neighbors. Most of the data that it sends back is used by scientist to find out what else human could expect from life in the outer space. The Hubble recently sent an image of the Messier 90, an amazing spiral galaxy. The images seem to show that it is close to Earth but it is in fact 60 million light years away from the Milky Way. It is located near the Virgo constellation. The galaxy is, in fact, a part of the Virgo Cluster which is made up of about different types of galaxies that is 1,200 strong ones.

    Ultraviolet, infrared and visible light all make up the image that was sent back to Earth. It was taken using the Wide Field and Planetary Camera 2 on the NASA Hubble Space Telescope. The camera used is made up of four light detectors that overlap each other in their field views. One of the cameras gave a rather higher magnification compared to what the other three gave. When all the images were put into one photo, the image with the higher magnification needed to resized in order for all the images to align properly. This gave the image that looks like the steps in a staircase.

    Messier 90 is considered as one of the more remarkable galaxies in existence in space. It is also seen as a galaxy that is traveling near the Earth and not away from it. The light from the galaxy shows an incoming motion that has been known as the blueshift phenomenon. Simply put, the light wavelength moves towards us. This movement pushes the light makes it all compressed and turned blue at the end of the spectrum.

    As the universe is seen to expand, most of the galaxies that surround the Milky Way seem to be moving farther. This is the reason why most of these galaxies are seen as red lights because they are moving towards the redshift of the spectrum. This new image of the Messier 90 send by the Hubble appears to be a rare exception.

    There is still much to be learned about the galaxies around us. And although the cluster itself is moving away from our galaxy, some of its constituent galaxies, like the Messier 90, is moving faster than the rest, making it seem as if it is moving towards us. Some of the galaxies in the cluster may be moving in the other direction making it seem as if it is moving far away from us in a faster velocity.

    See the full article here .

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

    Please help promote STEM in your local schools.

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    About Us

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    We provide credible news & info., in-depth reference material about diverse subjects that matter to everyone. We are a source for original and timely science and research information as well as breaking news in the various fields we represent.

     
  • richardmitnick 11:42 am on May 16, 2019 Permalink | Reply
    Tags: , , , , , NASA ESA Hubble   

    From Ethan Siegel: “We Have Now Reached The Limits Of The Hubble Space Telescope” 

    From Ethan Siegel
    May 16, 2019

    1
    The Hubble Space Telescope, as imaged during its last and final servicing mission. The only way it can point itself is from the internal spinning devices that allow it to change its orientation and hold a stable position. But what it can see is determined by its instruments, mirror, and design limitations. It has reached those ultimate limits; to go beyond them, we’ll need a better telescope. (NASA)

    The world’s greatest observatory can go no further with its current instrument set.

    The Hubble Space Telescope has provided humanity with our deepest views of the Universe ever. It has revealed fainter, younger, less-evolved, and more distant stars, galaxies, and galaxy clusters than any other observatory. More than 29 years after its launch, Hubble is still the greatest tool we have for exploring the farthest reaches of the Universe. Wherever astrophysical objects emit starlight, no observatory is better equipped to study them than Hubble.

    But there are limits to what any observatory can see, even Hubble. It’s limited by the size of its mirror, the quality of its instruments, its temperature and wavelength range, and the most universal limiting factor inherent to any astronomical observation: time. Over the past few years, Hubble has released some of the greatest images humanity has ever seen. But it’s unlikely to ever do better; it’s reached its absolute limit. Here’s the story.

    2
    The Hubble Space Telescope (left) is our greatest flagship observatory in astrophysics history, but is much smaller and less powerful than the upcoming James Webb (center). Of the four proposed flagship missions for the 2030s, LUVOIR (right) is by far the most ambitious. By probing the Universe to fainter objects, higher resolution, and across a wider range of wavelengths, we can improve our understanding of the cosmos in unprecedented ways. (MATT MOUNTAIN / AURA)

    NASA/ESA/CSA Webb Telescope annotated

    NASA Large UV Optical Infrared Surveyor (LUVOIR)

    From its location in space, approximately 540 kilometers (336 mi) up, the Hubble Space Telescope has an enormous advantage over ground-based telescopes: it doesn’t have to contend with Earth’s atmosphere. The moving particles making up Earth’s atmosphere provide a turbulent medium that distorts the path of any incoming light, while simultaneously containing molecules that prevent certain wavelengths of light from passing through it entirely.

    While ground-based telescopes at the time could achieve practical resolutions no better than 0.5–1.0 arcseconds, where 1 arcsecond is 1/3600th of a degree, Hubble — once the flaw with its primary mirror was corrected — immediately delivered resolutions down to the theoretical diffraction limit for a telescope of its size: 0.05 arcseconds. Almost instantly, our views of the Universe were sharper than ever before.

    3
    This composite image of a region of the distant Universe (upper left) uses optical (upper right) and near-infrared (lower left) data from Hubble, along with far-infrared (lower right) data from Spitzer. The Spitzer Space Telescope is nearly as large as Hubble: more than a third of its diameter, but the wavelengths it probes are so much longer that its resolution is far worse. The number of wavelengths that fit across the diameter of the primary mirror is what determines the resolution.(NASA/JPL-CALTECH/ESA)

    Sharpness, or resolution, is one of the most important factors in discovering what’s out there in the distant Universe. But there are three others that are just as essential:

    the amount of light-gathering power you have, needed to view the faintest objects possible,
    the field-of-view of your telescope, enabling you to observe a larger number of objects,
    and the wavelength range you’re capable of probing, as the observed light’s wavelength depends the object’s distance from you.

    Hubble may be great at all of these, but it also possesses fundamental limits for all four.

    4
    When you look at a region of the sky with an instrument like the Hubble Space Telescope, you are not simply viewing the light from distant objects as it was when that light was emitted, but also as the light is affected by all the intervening material and the expansion of space, that it experiences along its journey. Although Hubble has taken us farther back than any other observatory to date, there are fundamental limits to it, and reasons why it will be incapable of going farther. (NASA, ESA, AND Z. LEVAY, F. SUMMERS (STSCI))

    The resolution of any telescope is determined by the number of wavelengths of light that can fit across its primary mirror. Hubble’s 2.4 meter (7.9 foot) mirror enables it to obtain that diffraction-limited resolution of 0.05 arcseconds. This is so good that only in the past few years have Earth’s most powerful telescopes, often more than four times as large and equipped with state-of-the-art adaptive optics systems, been able to compete.

    To improve upon the resolution of Hubble, there are really only two options available:

    1. use shorter wavelengths of light, so that a greater number of wavelengths can fit across a mirror of the same size,
    2. or build a larger telescope, which will also enable a greater number of wavelengths to fit across your mirror.

    Hubble’s optics are designed to view ultraviolet light, visible light, and near-infrared light, with sensitivities ranging from approximately 100 nanometers to 1.8 microns in wavelength. It can do no better with its current instruments, which were installed during the final servicing mission back in 2009.

    5
    This image shows Hubble servicing Mission 4 astronauts practice on a Hubble model underwater at the Neutral Buoyancy Lab in Houston under the watchful eyes of NASA engineers and safety divers. The final servicing mission on Hubble was successfully completed 10 years ago; Hubble has not had its equipment or instruments upgraded since, and is now running up against its fundamental limitations. (NASA)

    Light-gathering power is simply about collecting more and more light over a greater period of time, and Hubble has been mind-blowing in that regard. Without the atmosphere to contend with or the Earth’s rotation to worry about, Hubble can simply point to an interesting spot in the sky, apply whichever color/wavelength filter is desired, and take an observation. These observations can then be stacked — or added together — to produce a deep, long-exposure image.

    Using this technique, we can see the distant Universe to unprecedented depths and faintnesses. The Hubble Deep Field was the first demonstration of this technique, revealing thousands of galaxies in a region of space where zero were previously known. At present, the eXtreme Deep Field (XDF) is the deepest ultraviolet-visible-infrared composite, revealing some 5,500 galaxies in a region covering just 1/32,000,000th of the full sky.

    6
    The Hubble eXtreme Deep Field (XDF) may have observed a region of sky just 1/32,000,000th of the total, but was able to uncover a whopping 5,500 galaxies within it: an estimated 10% of the total number of galaxies actually contained in this pencil-beam-style slice. The remaining 90% of galaxies are either too faint or too red or too obscured for Hubble to reveal, and observing for longer periods of time won’t improve this issue by very much. Hubble has reached its limits. (HUDF09 AND HXDF12 TEAMS / E. SIEGEL (PROCESSING))

    Of course, it took 23 days of total data taking to collect the information contained within the XDF. To reveal objects with half the brightness as the faintest objects seen in the XDF, we’d have to continue observing for a total of 92 days: four times as long. There’s a severe trade-off if we were to do this, as it would tie up the telescope for months and would only teach us marginally more about the distant Universe.

    Instead, an alternative strategy for learning more about the distant Universe is to survey a targeted, wide-field area of the sky. Individual galaxies and larger structures like galaxy clusters can be probed with deep but large-area views, revealing a tremendous level of detail about what’s present at the greatest distances of all. Instead of using our observing time to go deeper, we can still go very deep, but cast a much wider net.

    This, too, comes with a tremendous cost. The deepest, widest view of the Universe ever assembled by Hubble took over 250 days of telescope time, and was stitched together from nearly 7,500 individual exposures. While this new Hubble Legacy Field is great for extragalactic astronomy, it still only reveals 265,000 galaxies over a region of sky smaller than that covered by the full Moon.

    Hubble was designed to go deep, but not to go wide. Its field of view is extremely narrow, which makes a larger, more comprehensive survey of the distant Universe all but prohibitive. It’s truly remarkable how far Hubble has taken us in terms of resolution, survey depth, and field-of-view, but Hubble has truly reached its limit on those fronts.

    7
    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)

    Finally, there are the wavelength limits as well. Stars emits a wide variety of light, from the ultraviolet through the optical and into the infrared. It’s no coincidence that this is what Hubble was designed for: to look for light that’s of the same variety and wavelengths that we know stars emit.

    But this, too, is fundamentally limiting. You see, as light travels through the Universe, the fabric of space itself is expanding. This causes the light, even if it’s emitted with intrinsically short wavelengths, to have its wavelength stretched by the expansion of space. By the time it arrives at our eyes, it’s redshifted by a particular factor that’s determined by the expansion rate of the Universe and the object’s distance from us.

    Hubble’s wavelength range sets a fundamental limit to how far back we can see: to when the Universe is around 400 million years old, but no earlier.

    8
    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 all hope that the James Webb Space Telescope will discover them. (NASA, ESA, AND G. BACON (STSCI))

    The most distant galaxy ever discovered by Hubble, GN-z11, is right at this limit. Discovered in one of the deep-field images, it has everything imaginable going for it.

    It was observed across all the different wavelength ranges Hubble is capable of, with only its ultraviolet-emitted light showing up in the longest-wavelength infrared filters Hubble can measure.
    It was gravitationally lensed by a nearby galaxy, magnifying its brightness to raise it above Hubble’s naturally-limiting faintness threshold.
    It happens to be located along a line-of-sight that experienced a high (and statistically-unlikely) level of star-formation at early times, providing a clear path for the emitted light to travel along without being blocked.

    No other galaxy has been discovered and confirmed at even close to the same distance as this object.

    9
    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))

    Hubble may have reached its limits, but future observatories will take us far beyond what Hubble’s limits are. The James Webb Space Telescope is not only larger — with a primary mirror diameter of 6.5 meters (as opposed to Hubble’s 2.4 meters) — but operates at far cooler temperatures, enabling it to view longer wavelengths.

    At these longer wavelengths, up to 30 microns (as opposed to Hubble’s 1.8), James Webb will be able to see through the light-blocking dust that hampers Hubble’s view of most of the Universe. Additionally, it will be able to see objects with much greater redshifts and earlier lookback times: seeing the Universe when it was a mere 200 million years old. While Hubble might reveal some extremely early galaxies, James Webb might reveal them as they’re in the process of forming for the very first time.

    10
    The viewing area of Hubble (top left) as compared to the area that WFIRST will be able to view, at the same depth, in the same amount of time. The wide-field view of WFIRST will allow us to capture a greater number of distant supernovae than ever before, and will enable us to perform deep, wide surveys of galaxies on cosmic scales never probed before. It will bring a revolution in science, regardless of what it finds, and provide the best constraints on how dark energy evolves over cosmic time. (NASA / GODDARD / WFIRST)

    NASA/WFIRST

    Other observatories will take us to other frontiers in realms where Hubble is only scratching the surface. NASA’s proposed flagship of the 2020s, WFIRST, will be very similar to Hubble, but will have 50 times the field-of-view, making it ideal for large surveys. Telescopes like the LSST will cover nearly the entire sky, with resolutions comparable to what Hubble achieves, albeit with shorter observing times. And future ground-based observatories like GMT or ELT, which will usher in the era of 30-meter-class telescopes, might finally surpass Hubble in terms of practical resolution.

    At the limits of what Hubble is capable of, it’s still extending our views into the distant Universe, and providing the data that enables astronomers to push the frontiers of what is known. But to truly go farther, we need better tools. If we truly value learning the secrets of the Universe, including what it’s made of, how it came to be the way it is today, and what its fate is, there’s no substitute for the next generation of observatories.

    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 9:18 am on May 16, 2019 Permalink | Reply
    Tags: "Hubble Observes Creative Destruction as Galaxies Collide", , , , , Irregular galaxy NGC 4485, NASA ESA Hubble   

    From NASA/ESA Hubble Telescope: “Hubble Observes Creative Destruction as Galaxies Collide” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    16 May 2019
    Bethany Downer
    ESA/Hubble, Public Information Officer
    Garching, Germany
    Email: bethany.downer@partner.eso.org

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    1
    The NASA/ESA Hubble Space Telescope has taken a new look at the spectacular irregular galaxy NGC 4485, which has been warped and wound by its larger galactic neighbour. The gravity of the second galaxy has disrupted the ordered collection of stars, gas and dust, giving rise to an erratic region of newborn, hot, blue stars and chaotic clumps and streams of dust and gas.

    2
    NGC 4485 has been involved in a dramatic gravitational interplay with its larger galactic neighbour NGC 4490 — out of frame to the bottom right in this image. This ruined the original, ordered spiral structure of the galaxy and transformed it into an irregular one. The interaction also created a stream of material about 25 000 light-years long, connecting the two galaxies. The stream, visible to the right of the galaxy is made up of bright knots and huge pockets of gassy regions, as well as enormous regions of star formation in which young, massive, blue stars are born. Below NGC 4485 one can see a bright, orange background galaxy: CXOU J123033.6+414057. This galaxy is the source of X-ray radiation studied by the Chandra X-ray Observatory. It’s distance from Earth is about 850 million light-years.

    NASA/Chandra X-ray Telescope

    The irregular galaxy NGC 4485 has been involved in a dramatic gravitational interplay with its larger galactic neighbour NGC 4490 — out of frame to the bottom right in the top image. Found about 30 million light-years away in the constellation of Canes Venatici (the Hunting Dogs), the strange result of these interacting galaxies has resulted in an entry in the Atlas of Peculiar galaxies: Arp 269.

    Having already made their closest approach, NGC 4485 and NGC 4490 are now moving away from each other, vastly altered from their original states. Still engaged in a destructive yet creative dance, the gravitational force between them continues to warp each of them out of all recognition, while at the same time creating the conditions for huge regions of intense star formation.

    This galactic tug-of-war has created a stream of material about 25 000 light-years long which connects the two galaxies. The stream is made up of bright knots and huge pockets of gassy regions, as well as enormous regions of star formation in which young, massive, blue stars are born. Short-lived, however, these stars quickly run out of fuel and end their lives in dramatic explosions. While such an event seems to be purely destructive, it also enriches the cosmic environment with heavier elements and delivers new material to form a new generation of stars.

    Two very different regions are now apparent in NGC 4485; on the left are hints of the galaxy’s previous spiral structure, which was at one time undergoing “normal” galactic evolution. The right of the image reveals a portion of the galaxy ripped towards its larger neighbour, bursting with hot, blue stars and streams of dust and gas.

    This image, captured by the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, adds light through two new filters compared with an image released in 2014. The new data provide further insights into the complex and mysterious field of galaxy evolution.

    NASA/ESA Hubble WFC3

    See the full ESA/Hubble article here .
    See the full HubbleSite article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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