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  • richardmitnick 10:36 pm on May 16, 2018 Permalink | Reply
    Tags: Ant Nebula, , , , , ESA/Herschel   

    From European Space Agency: “A SPACE ANT FIRES ITS LASERS” 

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    From European Space Agency

    16 May 2018

    Isabel Aleman

    University of Sao Paulo, Brazil
    Leiden Observatory, The Netherlands

    Email: isabel.aleman@usp.br

    Toshiya Ueta
    University of Denver
    Email: toshiya.ueta@du.edu

    Albert Zijlstra
    University of Manchester / University of Hong Kong
    Email: albert.zijlstra@manchester.ac.uk

    Göran Pilbratt
    ESA Herschel project scientist
    Email: gpilbratt@cosmos.esa.int

    Markus Bauer








    ESA Science Communication Officer









    Tel: +31 71 565 6799









    Mob: +31 61 594 3 954









    Email: markus.bauer@esa.int

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    Ant Nebula

    A rare phenomenon connected to the death of a star has been discovered in observations made by ESA’s Herschel space observatory: an unusual laser emission from the spectacular Ant Nebula, which suggests the presence of a double star system hidden at its heart.

    ESA/Herschel spacecraft active from 2009 to 2013

    When low- to middleweight stars like our Sun approach the end of their lives they eventually become dense, white dwarf stars. In the process, they cast off their outer layers of gas and dust into space, creating a kaleidoscope of intricate patterns known as a planetary nebula.

    The infrared Herschel observations have shown that the dramatic demise of the central star in the core of the Ant Nebula is even more theatrical than implied by its colourful appearance in visible images – such as those taken by the NASA/ESA Hubble Space Telescope. As revealed by the new data, the Ant Nebula also beams intense laser emission from its core.

    While lasers in everyday life today might mean special visual effects in music concerts, in space, focused emission is detected at different wavelengths under specific conditions. Only a few of these space infrared lasers are known.

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    Stellar evolution

    By coincidence, astronomer Donald Menzel who first observed and classified this particular planetary nebula in the 1920s (it is officially known as Menzel 3 after him) was also one of the first to suggest that in certain conditions natural ‘light amplification by stimulated emission of radiation’ – from which the acronym ‘laser’ derives – could occur in gaseous nebulae. This was well before the discovery and first successful operation of lasers in laboratories in 1960, an occasion which is now celebrated annually on 16 May as International Day of Light.

    “When we observe Menzel 3, we see an amazingly intricate structure made up of ionized gas, but we cannot see the object in its centre producing this pattern,” says Isabel Aleman, lead author of a paper describing the new results [Herschel Planetary Nebula Survey (HerPlaNS): Hydrogen Recombination Laser Lines in Mz 3 MNRAS.

    “Thanks to the sensitivity and wide wavelength range of the Herschel observatory, we detected a very rare type of emission called hydrogen recombination line laser emission, which provided a way to reveal the nebula’s structure and physical conditions.”

    This kind of laser emission needs very dense gas close to the star. Comparison of the observations with models found that the density of the laser-emitting gas is around ten thousand times higher than that of the gas seen in typical planetary nebulae and in the lobes of the Ant Nebula itself.

    Normally, the region close to the dead star – close in this case being about the distance of Saturn from the Sun – is quite empty, because most of its material is ejected outwards. Any lingering gas would soon fall back onto it.

    “The only way to keep gas close to the star is if it is orbiting around it in a disc,” says co-author Albert Zijlstra. “In this case, we have actually observed a dense disc in the very centre that is seen approximately edge-on. This orientation helps to amplify the laser signal. The disc suggests the white dwarf has a binary companion, because it is hard to get the ejected gas to go into orbit unless a companion star deflects it in the right direction.”

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    Herschel in the cleanroom.No image credit.

    Astronomers have not yet seen the expected second star, but they think that the mass from the dying companion star is being ejected and then captured by the compact central star of the original planetary nebula, producing the disc where the laser emission is produced.

    “We used Herschel to characterise various components of gas and dust in nebula around old stars, but we were not necessarily looking for a laser phenomenon,” adds Toshiya Ueta, principal investigator of the Herschel Planetary Nebula Survey project. “Such emission has only been identified in a handful of objects before; this was a remarkable discovery that we did not anticipate. There is certainly more to stellar nebulae than meets the eye!”

    “This study suggests that the distinctive Ant Nebula as we see it today was created by the complex nature of a binary star system, which influences the shape, chemical properties, and evolution in these final stages of a star’s life,” says Göran Pilbratt, ESA’s Herschel project scientist.

    “Herschel offered the perfect observing capabilities to detect this extraordinary laser in the Ant Nebula. The findings will help constrain the conditions under which this phenomenon occurs, and help us to refine our models of stellar evolution. It is also a happy conclusion that the Herschel mission was able to connect together Menzel’s two discoveries from almost a century ago.”

    See the full article here .

    Please help promote STEM in your local schools.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 8:14 am on March 26, 2018 Permalink | Reply
    Tags: , , , , , ESA/Herschel,   

    From ESA: “Chaotic web of filaments in a Milky Way stellar nursery” 

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    European Space Agency

    26/03/2018

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    Chaotic web of filaments in a Milky Way stellar nursery. ESA/Herschel/PACS, SPIRE/Hi-GAL Project. Acknowledgement: UNIMAP / L. Piazzo, La Sapienza – Università di Roma; E. Schisano / G. Li Causi, IAPS/INAF, Italy

    ESA/Herschel spacecraft

    The plane of the Milky Way is rich in star-forming regions, such as the one pictured in this stunning scene by ESA’s Herschel space observatory. To the far-infrared eye of Herschel, this region reveals an intricate network of gas filaments and dark bubbles interspersed by bright hotspots where new stars come to life.

    The cooler regions, which emit light at longer wavelengths, are displayed in a red-brownish colour. Hotter areas, where star formation is more intense, shine in blue and white tones. Some areas are particularly bright, suggesting a number of luminous, massive stars are forming there.

    Particularly striking is the chaotic web of gas filaments we see in this scene. Astronomers think there is a link between star formation and the filamentary structures in the interstellar medium. In the densest strands, the gas that makes up the filaments becomes unstable and forms clumps of material bound together by gravity. If dense enough, these collapsed blobs of gas eventually go on to become newborn stars.

    Observations by Herschel showed the filamentary complexity to be ubiquitous in the plane of our Galaxy, from a few to hundreds of light-years. In nearby star-forming clouds, within 1500 light-years of the Sun, these filaments seem to be roughly all the same width – about a third of a light-year. This suggests a common physical mechanism in their origin, possibly linked to the turbulent nature of interstellar gas clouds.

    The star-formation region in this image, centred around –70º longitude in galactic coordinates, is located in the Carina neighbourhood, home to the glorious Carina Nebula. Located some 7500 light-years away, Carina is one of the largest clouds of gas and dust in the plane of the Milky Way. It hosts the famous Eta Carinae, one of the most luminous and massive stellar systems in our galaxy.

    Nebula in the constellation Carina, contains the central cluster of huge, hot stars, called NGC 3603. NASA/ESA Hubble

    Eta Carinae Image Credit: N. Smith, J. A. Morse (U. Colorado) et al., NASA

    Herschel, which operated from 2009 until 2013, was a large space telescope observing in the far-infrared and submillimetre parts of the spectrum. This spectral range is ideal to observe the glow from cool dust in the regions where stars form. As part of Hi-GAL, the Herschel infrared Galactic Plane Survey, the observatory surveyed the plane of our Galaxy, exploring the Milky Way’s star-formation regions in unprecedented detail. This image, a product of Hi-GAL, combines observations at three different wavelengths: 70 microns (blue), 160 microns (green) and 250 microns (red).

    See the full article here .

    Please help promote STEM in your local schools.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 7:47 am on September 22, 2017 Permalink | Reply
    Tags: , , , , , ESA/Herschel, From stars to galaxies   

    From ESA: “From stars to galaxies”, ESA/Herschel 

    ESA Space For Europe Banner

    European Space Agency

    9.22.17

    Explore stellar nurseries in our Milky Way and other galaxies as viewed through the infrared eye of the Herschel space observatory.

    ESA/Herschel spacecraft

    Herschel’s view of new stars and molecular clouds

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    Credits: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech), CC BY-SA 3.0 IGO

    The bubbles and wisps portrayed in this image by ESA’s Herschel observatory reveal great turmoil in the W3/W4/W5 complex of molecular clouds and star-forming regions. Located over 6000 light-years away, in the northern constellation Cassiopeia, it is one of the best regions in which to study the life and death of massive stars in our Milky Way galaxy.

    Observing the sky at far-infrared and submillimetre wavelengths from 2009 to 2013, Herschel could catch the faint glow of dust grains interspersed in these clouds. Astronomers can use this glow to trace the otherwise dark gas where star formation unfolds.

    The three regions that make up the complex – W3, W4 and W5 – owe their name to astronomer Gart Westerhout, who identified them in the 1950s as the third, fourth and fifth sources of his survey of the Galaxy at radio wavelengths.

    The bright, white region towards the top right of the image, hosting three brilliant spots, is W3, a giant molecular cloud containing one of the most active factories of massive stars in the outer Milky Way. For its star-making activity, the cloud draws from a total reservoir of raw material equivalent to several hundred thousand times the mass of our Sun.

    The large, blue-greenish cavity to the lower left of W3 is W4, a bubble carved by winds and supernova explosions of the massive stars in IC1805, the star-forming region at its core.

    The other large cavity, on the left side of the image, is W5, consisting of two adjacent bubbles powered by intense winds and explosions of the massive stars that are coming to life in several stellar nurseries nestled within this region.

    Many seeds of new stars in this complex, especially in W3 and W5, have been observed along pillars, edges and other features that are being sculpted in the cloud material by the mighty effects of nearby massive stars. This suggests that each generation of stars is triggering the formation of the next one.

    While these regions are prime locations to study the poorly understood processes that lead to the formation of massive stars, they also host large amounts of young, low-mass stars, providing astronomers with an extraordinary laboratory to investigate the full complexity of star formation in the Milky Way.

    This two-colour image combines Herschel observations at 70 microns (cyan) and 100 microns (orange), and spans about 8.4° by 2.9°; north is up and east to the left.

    Full story: How Herschel unlocked the secrets of star formation
    Credits: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech), CC BY-SA 3.0 IGO

    Herschel’s view of the Taurus molecular cloud

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    Credits: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech), CC BY-SA 3.0 IGO

    This mosaic combines several observations of the Taurus Molecular Cloud performed by ESA’s Herschel observatory. Located about 450 light-years from us, in the constellation Taurus, the Bull, this vast complex of interstellar clouds is where a myriad of stars are being born, and is the closest large region of star formation.

    Observing the sky at far-infrared and submillimetre wavelengths from 2009 to 2013, Herschel could catch the faint glow of dust grains dispersed through these clouds. Astronomers can use this glow to trace the otherwise dark gas where star formation unfolds.

    The darker, blue-hued areas throughout the image correspond to colder, less dense portions of the cloud, while the brighter, red-hued regions are the densest environments, where the star-forming activity is most intense.

    The densest regions are distributed along an intricate network of filaments, teeming with bright clumps: the seeds of future stars. This is a textbook example of the filamentary structures that were spotted by Herschel nearly everywhere in the Galaxy, demonstrating the key role of filaments in star formation.

    Embedded in the bright clump towards the top left of the image is Lynds 1544, a pre-stellar core that will later turn into a star. Here, Herschel detected water vapour – the first time this molecule was ever found in a prestellar core – in an amount that exceeds, by over 2000 times, the water content of Earth’s oceans.

    Herschel observations of the tangled structures in the top right of the image have shown that the material along filaments is not at all static. In fact, the most prominent filaments appear to be drawing matter from their surroundings through a network of lower-density filaments, known as striations, perpendicular to the main filament. In these regions, astronomers found that magnetic fields tend to be perpendicular to the densest, star-forming filaments and parallel to the striations, indicating that they must also play an important role in the processes that lead to stellar birth.

    This four-colour image combines Herschel observations at 160 microns (blue), 250 microns (green), 350 microns (split between green and red) and 500 microns (red), and spans 13.8° by 7.3°; north is up and east to the left.

    Full story: The cosmic water trail uncovered by Herschel

    Herschel’s view of the Pinwheel Galaxy

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    This image shows the Pinwheel Galaxy, also known as Messier 101, as viewed by ESA’s Herschel observatory. Lying more than 20 million light-years from us, this spiral galaxy is similar in shape to our Milky Way, but it is almost twice as large.

    Herschel’s observations at far-infrared and submillimetre wavelengths reveal the glow of cosmic dust, which is a minor but crucial ingredient in the interstellar material in the galaxy’s spiral arms. This mixture of gas and dust provides the raw material to produce the galaxy’s future generations of stars.

    The Pinwheel Galaxy is in the constellation Ursa Major, the Big Dipper. Thanks to its orientation, we can enjoy a face-on view of the beautiful spiral structure of the galaxy’s disc.

    The spiral arms are dotted with several bright, blue-hued spots of light: these are regions where large numbers of massive stars are being born.

    This three-colour image combines Herschel observations at 70 and 100 microns (blue), 160 and 250 microns (green), and 350 and 500 microns (red). North is up and east to the left.

    Full story: Herschel’s chronicles of galaxy evolution

    Herschel’s view of NGC 1097

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    Credits: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech),

    Portrayed in this image by ESA’s Herschel observatory is NGC 1097, a barred spiral galaxy located some 50 million light-years from us, in the southern constellation Fornax, the Furnace.

    The blue regions sprinkled across the galaxy’s two spiral arms are sites of intense star formation. There, the energy from newborn stars has heated up the dust interspersed in the interstellar gas, making it glow at the far-infrared and submillimetre wavelengths probed by Herschel.

    The dwarf elliptical galaxy NGC 1097A, a small satellite of NGC 1097, can be seen as the fuzzy blue blob in the top right, halfway between the two spiral arms.

    The bright core of the NGC 1097, surrounded by a glowing ring where most of the galaxy’s prodigious star formation is taking place, conceals a supermassive black hole about a hundred million times the mass of our Sun. This black hole is devouring matter from its vicinity, causing the galactic core to shine brightly across the electromagnetic spectrum, from X-rays to radio waves.

    This galaxy was discovered – and originally identified as a nebula – in the late 18th century in optical observations by William Herschel, the astronomer after whom the observatory is named. Despite the source’s location in the southern sky, it was still visible a few degrees above the horizon at the site in England where Herschel made his observations.

    This three-colour image combines Herschel observations at 70 and 100 microns (blue), 160 and 250 microns (green), and 350 and 500 microns (red). North is up and east to the left.

    Herschel’s view of a star nursery

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    Credits: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech), CC BY-SA 3.0 IGO

    This image shows Rho Ophiuchi, a vast stellar nursery where new stars take shape from billowing clouds of gas, as viewed by ESA’s Herschel observatory. Located about 440 light-years from us, in the constellation Ophiuchus, the Serpent Bearer, Rho Ophiuchi is one of the nearest star-forming regions to Earth.

    Some of these clouds appear dark when observed at optical and near-infrared wavelengths owing to the presence of dust, a minor but crucial component of the interstellar medium that pervades our Galaxy. However, they appeared anything but dark to the infrared eye of Herschel.

    Observing the sky at far-infrared and submillimetre wavelengths from 2009 to 2013, Herschel could catch the faint glow of dust grains interspersed in these clouds. Astronomers can use this glow to trace the otherwise dark gas where star formation unfolds.

    Herschel’s view reveals a tangled network of filaments, weaving their way from the darker, less dense regions on the left of the image towards the brighter, denser parts of the cloud, on the right. The bright clumps embedded in the cloud are the seeds of future stars and planets.

    Filaments like these were uncovered by Herschel throughout the Galaxy, indicating that these structures play a fundamental role in the processes that lead to the birth of stars.

    This three-colour image combines Herschel observations at 70 microns (blue), 160 microns (green) and 250 microns (red), and spans 7.9° by 4.6°; north is up and east to the left.

    See the full article here .

    Please help promote STEM in your local schools.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 8:39 am on September 19, 2017 Permalink | Reply
    Tags: , , , , , ESA/Herschel   

    From ESA: “Celebrating Herschel’s legacy” 

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    European Space Agency

    18/09/2017

    ESA/Herschel spacecraft

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    ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech), CC BY-SA 3.0 IGO

    This delicate image showing the intricacies of interstellar bubbles and wisps reveals great turmoil in the W3/W4/W5 complex of molecular clouds and star-forming regions. It was taken by ESA’s Herschel Space Observatory, a trailblazing mission that observed the sky in far-infrared and submillimetre wavelengths between 2009 and 2013.

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    Reservoir of cold gas in the constellation of the Southern Cross
    2 October 2009

    Herschel has delivered spectacular vistas of cold gas clouds lying near the plane of the Milky Way, revealing intense, unexpected activity. The dark, cool region is dotted with stellar factories, like pearls on a cosmic string.

    On 3 September, Herschel aimed its telescope at a reservoir of cold gas in the constellation of the Southern Cross near the Galactic Plane. As the telescope scanned the sky, the spacecraft’s Spectral and Photometric Imaging REceiver, SPIRE, and Photoconductor Array Camera and Spectrometer, PACS instruments snapped the pictures. The region is located about 60° from the Galactic Centre, thousands of light-years from Earth.

    The five original infrared wavelengths have been colour-coded to allow scientists to differentiate extremely cold material (red) from the surrounding, slightly warmer stuff (blue).

    The images reveal structure in cold material in our Galaxy, as we have never seen it before, and even before a detailed analysis, scientists have gleaned information on the quantity of the material, its mass, temperature, composition and whether it is collapsing to form new stars.

    September has often been the month of memorable moments or milestones for Herschel.

    When the satellite was still on Earth, it was in September 2005 that the assembled telescope passed its first tests.

    September 2007 saw the mating of the mission’s ‘brain’ – the payload module with the instruments and the cryostat that would keep them at the required temperature, just above absolute zero – with its ‘heart’, or the service module, that would to keep the spacecraft going.

    During the same month, scientists gathered to plan how to get the most of this extraordinary mission from the observing time that would be available.

    Finally, the satellite was launched on 14 May 2009. A few months later, it was again in September that the first Herschel science observations were performed – a memorable moment for many astronomers across the world.

    Eight years later, as the mission approaches retirement, ESA celebrates the marvellous science that it has achieved and takes stock of the legacy that Herschel leaves behind.

    One of the areas where Herschel has made substantial contributions concerns the processes that lead to the formation of stars, surveying a large number of stellar nurseries like the W3/W4/W5 complex portrayed in this image.

    Read more about Herschel’s unprecedented glimpse into the stellar cradles of our Galaxy and the giant strides that have been taken in our understanding of how stars and their planetary systems come to life.


    Herschel: star formation. Click here for details and large versions of the video. Credit: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: T. Pyle & R. Hurt (JPL-Caltech)

    Among many other exciting findings, Herschel’s observations have also traced the trail of water across the cosmos, and pieced together the evolution of galaxies throughout 14 billion years of the Universe’s history. Follow Herschel Week to read more about these fascinating discoveries and about the legacy that the mission leaves for the future generations of telescopes.

    Join ESA to celebrate Herschel Week and share your memorable #HerschelMoments

    See the full article here .

    Please help promote STEM in your local schools.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 12:19 pm on August 5, 2017 Permalink | Reply
    Tags: , , , , ESA/Herschel, Westerhout 43 region   

    From ESA: “Intense star formation in the Westerhout 43 region” 

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    European Space Agency

    1
    Intense star formation in the Westerhout 43 region. Released 31/07/2017. Copyright ESA/Herschel/PACS, SPIRE/Hi-GAL Project. Acknowledgement: UNIMAP / L. Piazzo, La Sapienza – Università di Roma; E. Schisano / G. Li Causi, IAPS/INAF, Italy

    ESA/Herschel spacecraft

    Hidden from our sight, the Westerhout 43 star-forming region is revealed in full glory in this far-infrared image from ESA’s Herschel space observatory. This giant cloud, where a multitude of massive stars come to life in the billowing gas and dust, is almost 20 000 light-years away from the Sun, in the constellation of Aquila, the Eagle.

    Massing more than seven million Suns, this region is home to over 20 stellar nurseries, which are being heated by the powerful light from newborn stars within. These hubs of star formation stand out in blue hue against the cooler yellow and red surroundings.

    Nestled in the glowing blue bubble of gas at the centre of the image is a cluster of extremely hot and massive Wolf-Rayet and OB stars, which together are over a million times brighter than our Sun. This bubble, hosting the seeds that will grow into several new stellar clusters, is one of the most prolific birthplaces of stars in our Galaxy.

    A less extreme but still very active stellar factory is the large complex of blue bubbles visible in the image towards the right. Scrutinising the Herschel images, astronomers have found evidence of what appears like a network of filaments linking these two intense hubs of star formation.

    Located in a very dynamic region of the Milky Way, at the transition between the central bar of the Galaxy and one of its spiral arms, Westerhout 43 is an excellent laboratory to study how stars – especially massive ones – take shape at the collision of two large flows of interstellar matter.

    Investigating star-forming regions across our Galaxy in unprecedented detail was one of the main goals of Herschel, which was launched in 2009 and operated for almost four years, observing the sky at far-infrared and submillimetre wavelengths. Sensitive to the heat from the small fraction of cold dust mixed in with the clouds of gas where stars form, imaging such regions points astronomers to dense areas of gas where new stars are being born, enabling them to study the action in detail, just as in this image.

    This three-colour image combines Herschel observations at 70 microns (blue), 160 microns (green) and 250 microns (red), and spans about 3º on the long side; north is up and east to the left. The image was obtained as part of Herschel’s Hi-GAL key-project, which imaged the entire plane of the Milky Way in five different infrared bands. A video panorama compiling all Hi-GAL observations was published in April 2016.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 12:13 pm on July 15, 2017 Permalink | Reply
    Tags: , Angular momentum, , , , , Elliptical galaxies, ESA/Herschel, , Shedding light on galaxies' rotation secrets,   

    From EurekaAlert: “Shedding light on galaxies’ rotation secrets” 

    eurekaalert-bloc

    EurekaAlert

    13-Jul-2017

    Media Contact
    Donato Ramani
    ramani@sissa.it
    39-342-802-2237
    http://www.sissa.it/

    Spiral galaxies are strongly rotating whereas the rotation velocity of ellipticals is much lower. A new study investigates the reasons of such a dichotomy revealing that it is imprinted at formation.

    Scuola Internazionale Superiore di Studi Avanzati

    1
    Spiral galaxies are found to be strongly rotating, with an angular momentum higher by a factor of about 5 than ellipticals. What is the origin of such a difference?
    Credit Wikimedia Common.

    The dichotomy concerns the so-called angular momentum (per unit mass), that in physics is a measure of size and rotation velocity. Spiral galaxies are found to be strongly rotating, with an angular momentum higher by a factor of about 5 than ellipticals. What is the origin of such a difference? An international research team investigated the issue in a study just published in the Astrophysical Journal. The team was led by SISSA Ph.D. student JingJing Shi under the supervision of Prof. Andrea Lapi and Luigi Danese, and in collaboration with Prof. Huiyuan Wang from USTC (Hefei) and Dr. Claudia Mancuso from IRA-INAF (Bologna). The researchers inferred from observations the amount of gas fallen into the central region of a developing galaxy, where most of the star formation takes places.

    The outcome is that in elliptical galaxies only about 40% of the available gas fell into that central region. More relevantly, this gas fueling star formation was characterized by a rather low angular momentum since the very beginning. This is in stark contrast with the conditions found in spirals, where most of the gas ending up in stars had an angular momentum appreciably higher. In this vein, the researchers have traced back the dichotomy in the angular momentum of spiral and elliptical galaxies to their different formation history. Elliptical galaxies formed most of their stars in a fast collapse where angular momentum is dissipated. This process is likely stopped early on by powerful gas outflows from supernova explosions, stellar winds and possibly even from the central supermassive black hole. For spirals, on the other hand, the gas infelt slowly conserving its angular momentum and stars formed steadily along a timescale comparable to the age of the Universe.

    “Till recent years, in the paradigm of galaxy formation and evolution, elliptical galaxies were thought to have formed by the merging of stellar disks in the distant Universe. Along this line, their angular momentum was thought to be the result of dissipative processes during such merging events” say the researchers. Recently, this paradigm had been challenged by far-infrared/sub-millimeter observations brought about by the advent of space observatories like Herschel and ground based interferometers like the Atacama Large Millimeter Array (ALMA).

    ESA/Herschel spacecraft

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

    These observations have the power of penetrating through interstellar dust and so to unveil the star formation processes in the very distant, dusty galaxies, that constituted the progenitors of local ellipticals. “The net outcome from these observations is that the stars populating present-day ellipticals are mainly formed in a fast dissipative collapse in the central regions of dusty starforming galaxies. After a short timescale of less than 1 billion years the star formation has been quenched by powerful gas outflows”. Despite this change of perspective, the origin of the low angular momentum observed in local ellipticals still remained unclear.

    “This study reconciles the low angular momentum observed in present-day ellipticals with the new paradigm emerging from Herschel and ALMA observations of their progenitors” conclude the scientists. “We demonstrated that the low angular momentum of ellipticals is mainly originated by nature in the central regions during the early galaxy formation process, and not nurtured substantially by the environment via merging events, as envisaged in previous theories”.

    See the full article here .

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    Since 1996, EurekAlert! has served as the leading destination for scientific organizations seeking to disseminate news to reporters and the public. Today, thousands of reporters around the globe rely on EurekAlert! as a source of ideas, background information, and advance word on breaking news stories.

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  • richardmitnick 4:36 pm on June 21, 2017 Permalink | Reply
    Tags: , , , , ESA/Herschel, Moon orbiting the dwarf planet 2007 OR10, , ,   

    From Universe Today: “An Astronomical Detective Tale and the Moon of 2007 OR10” 

    universe-today

    Universe Today

    21 June , 2017
    David Dickinson

    1
    These two images reveal a moon orbiting the dwarf planet 2007 OR10. NASA/Hubble/ESA/STScI

    NASA/ESA Hubble Telescope

    It isn’t every day we get a new moon added to the list of solar system satellites. The combined observational power of three observatories — Kepler, Herschel and Hubble — led an astronomical detective tale to its climatic conclusion: distant Kuiper Belt Object 2007 OR10 has a tiny moon.

    NASA/Kepler Telescope

    ESA/Herschel spacecraft

    See the full article here .

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  • richardmitnick 12:55 pm on October 12, 2016 Permalink | Reply
    Tags: , , ESA/Herschel,   

    From JPL-Caltech: “Building Blocks of Life’s Building Blocks Come From Starlight” 

    NASA JPL Banner

    JPL-Caltech

    October 12, 2016
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

    1
    This immense nebula is the closest large region of star formation, situated about 1,500 light years away in the constellation of Orion. The parts that are easily observed in visible light, known alternatively as the Orion Nebula or Messier 42, correspond to the light blue regions. This is the glow from the warmest dust, illuminated by clusters of hot stars that have only recently been born in this chaotic region. The red spine of material running from corner to corner reveals colder, denser filaments of dust and gas that are scattered throughout the Orion nebula. In visible light this would be a dark, opaque feature, hiding the reservoir of material from which stars have recently formed and will continue to form in the future.

    Herschel data from the PACS instrument observations, at wavelengths of 100 and 160 microns, is displayed in blue and green, respectively, while SPIRE 250-micron data is shown in red. Within the inset image, the emission from ionized carbon atoms (C+), overlaid in yellow, was isolated and mapped out from spectrographic data obtained by the HIFI instrument. A version without the inset is also available.

    Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. While the observatory stopped making science observations in April 2013, after running out of liquid coolant as expected, scientists continue to analyze its data. NASA’s Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel’s three science instruments. The NASA Herschel Science Center, part of IPAC, supports the U.S. astronomical community. Caltech manages JPL for NASA.

    More information about Herschel is available at http://www.herschel.caltech.edu, http://www.nasa.gov/herschel and http://www.esa.int/SPECIALS/Herschel.

    Life exists in a myriad of wondrous forms, but if you break any organism down to its most basic parts, it’s all the same stuff: carbon atoms connected to hydrogen, oxygen, nitrogen and other elements. But how these fundamental substances are created in space has been a longstanding mystery.

    Now, astronomers better understand how molecules form that are necessary for building other chemicals essential for life. Thanks to data from the European Space Agency’s Herschel Space Observatory, scientists have found that ultraviolet light from stars plays a key role in creating these molecules, rather than “shock” events that create turbulence, as was previously thought.

    Scientists studied the ingredients of carbon chemistry in the Orion Nebula, the closest star-forming region to Earth that forms massive stars. They mapped the amount, temperature and motions of the carbon-hydrogen molecule (CH, or “methylidyne” to chemists), the carbon-hydrogen positive ion (CH+) and their parent: the carbon ion (C+). An ion is an atom or molecule with an imbalance of protons and electrons, resulting in a net charge.

    “On Earth, the sun is the driving source of almost all the life on Earth. Now, we have learned that starlight drives the formation of chemicals that are precursors to chemicals that we need to make life,” said Patrick Morris, first author of the paper and researcher at the Infrared Processing and Analysis Center at Caltech in Pasadena.

    In the early 1940s, CH and CH+ were two of the first three molecules ever discovered in interstellar space. In examining molecular clouds — assemblies of gas and dust — in Orion with Herschel, scientists were surprised to find that CH+ is emitting rather than absorbing light, meaning it is warmer than the background gas. The CH+ molecule needs a lot of energy to form and is extremely reactive, so it gets destroyed when it interacts with the background hydrogen in the cloud. Its warm temperature and high abundance are therefore quite mysterious.

    Why, then, is there so much CH+ in molecular clouds such as the Orion Nebula? Many studies have tried to answer this question before, but their observations were limited because few background stars were available for studying. Herschel probes an area of the electromagnetic spectrum — the far infrared, associated with cold objects — that no other space telescope has reached before, so it could take into account the entire Orion Nebula instead of individual stars within. The instrument they used to obtain their data, HIFI, is also extremely sensitive to the motion of the gas clouds.

    One of the leading theories about the origins of basic hydrocarbons has been that they formed in “shocks,” events that create a lot of turbulence, such as exploding supernovae or young stars spitting out material. Areas of molecular clouds that have a lot of turbulence generally create shocks. Like a large wave hitting a boat, shock waves cause vibrations in material they encounter. Those vibrations can knock electrons off atoms, making them ions, which are more likely to combine. But the new study found no correlation between these shocks and CH+ in the Orion Nebula.

    Herschel data show that these CH+ molecules were more likely created by the ultraviolet emission of very young stars in the Orion Nebula, which, compared to the sun, are hotter, far more massive and emit much more ultraviolet light. When a molecule absorbs a photon of light, it becomes “excited” and has more energy to react with other particles. In the case of a hydrogen molecule, the hydrogen molecule vibrates, rotates faster or both when hit by an ultraviolet photon.

    It has long been known that the Orion Nebula has a lot of hydrogen gas. When ultraviolet light from large stars heats up the surrounding hydrogen molecules, this creates prime conditions for forming hydrocarbons. As the interstellar hydrogen gets warmer, carbon ions that originally formed in stars begin to react with the molecular hydrogen, creating CH+. Eventually the CH+ captures an electron to form the neutral CH molecule.

    “This is the initiation of the whole carbon chemistry,” said John Pearson, researcher at NASA’s Jet Propulsion Laboratory, Pasadena, California, and study co-author. “If you want to form anything more complicated, it goes through that pathway.”

    Scientists combined Herschel data with models of molecular formation and found that ultraviolet light is the best explanation for how hydrocarbons form in the Orion Nebula.

    The findings have implications for the formation of basic hydrocarbons in other galaxies as well. It is known that other galaxies have shocks, but dense regions in which ultraviolet light dominates heating and chemistry may play the key role in creating fundamental hydrocarbon molecules there, too.

    “It’s still a mystery how certain molecules get excited in the cores of galaxies,” Pearson said. “Our study is a clue that ultraviolet light from massive stars could be driving the excitation of molecules there, too.”

    See the full article here .

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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    NASA image

     
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