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  • richardmitnick 10:41 pm on January 14, 2021 Permalink | Reply
    Tags: "China Opens World's Largest Radio Telescope to International Scientists", , , , , Five-hundred-meter Aperture Spherical Telescope (FAST), , Sky & Telescope   

    From Sky & Telescope: “China Opens World’s Largest Radio Telescope to International Scientists” 

    From Sky & Telescope

    January 13, 2021
    Andrew Jones

    China is making its Five-hundred-meter Aperture Spherical Telescope (FAST) available to international scientists in the wake of the collapse of the Arecibo telescope in Puerto Rico late last year.

    NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft), which has now collapsed.

    FAST [Five-hundred-meter Aperture Spherical Telescope] radio telescope, with phased arrays from CSIRO engineers Australia located in the Dawodang depression in Pingtang County, Guizhou Province, South China.

    1
    This diagram represents a pulsar detected during FAST’s trial period. The telescope came fully online in January 2020.
    National Astronomical Observatories of China [国家天文台] at CAS [中国科学院](CN)

    The National Astronomical Observatories of China [国家天文台](NAOC)(CN), the telescope’s operator, confirmed on January 4th that scientists outside of China will be able to apply for time using the facility on April 1st. A timetable for observation will then be published by August 1st.

    Jiang Peng, FAST’s chief engineer, said about 10% of the observation time will be allocated to foreign scientists in the first year of the telescope’s opening to the global scientific community.

    The facility’s scientific committee also stated that FAST will become increasingly open to international teams. FAST’s collecting area and sensitivity are expected to make a range of contributions to radio astronomy and are therefore of great interest internationally.

    Also known as Tianyan, or the Eye of Heaven, FAST is the world’s largest single-dish telescope, situated in a karst depression in Pingtang, Guizhou province in southwest China. Nearby settlements were relocated to reduce electromagnetic emissions which could interfere with the telescope’s sensitive operations.

    FAST and Arecibo

    Like Arecibo, FAST’s receivers are suspended high above the dish. The dish itself consists of 4,450 triangular panels, which can be controlled by more than 2,000 mechanical winches. This allows researchers to maneuver to focus on different areas of the sky.

    With a deeper dish and panel system, FAST can cover a swath of sky within 40° of its zenith, while Arecibo was limited to 20°. However, unlike Arecibo, its receivers do not have radar capability, so it cannot investigate near-Earth objects.

    FAST is more than 2.5 times more sensitive than Arecibo, according to the National Astronomical Observatories, under the Chinese Academy of Sciences, which means that FAST can see fainter sources from farther away. FAST also has a greater effective collecting area (71,000 square meters), than the 305-meter-wide Arecibo (50,000 square meters).

    Wang Qiming, chief inspector of FAST’s operations and development center, told AFP in December, that he had visited Arecibo, which influenced China’s own plans.

    “We drew a lot of inspiration from its structure, which we gradually improved to build our telescope,” Wang said.

    The telescope began operations in September 2016 and officially entered service on January 11, 2020.


    Trial Operation for China’s FAST Telescope to End Soon

    FAST Possibilities

    FAST features an innovative 19-beam receiver developed by Chinese and Australian scientists that enables sensitive observations for a number of scientific goals.

    Researchers will be able to conduct studies and observations across a range of areas of interest, including pulsar discovery, galaxy evolution, and the large-scale nature of the universe. For example, FAST detected more than 240 pulsars and pulsar candidates by November 2020. These include an eclipsing binary millisecond pulsar in globular cluster Messier 92. The total number of pulsars FAST detects should reach 1,000 over the next five years, according to director of the FAST Science Committee, Wu Xiangping. Lists of detected pulsars can be found here, as well as those discovered through a Galactic Plane Pulsar Snapshot survey here.

    The giant facility has also contributed to the study of fast radio bursts (FRBs) and magnetars, and it has made observations for the Search for extraterrestrial intelligence (SETI), including microware surveys to look for weak space signals.

    FAST is also monitoring some of the pulsars it has detected to help find the signal of gravitational waves at nanohertz frequencies, joining efforts underway in the U.S., Europe, and Australia since 2005.

    The facility may also extend China’s deep-space exploration and communication capabilities to the edge of the solar system.

    “Although this telescope was built by the Chinese people, we should have the mind of a big country and contribute to the exploration of the mysteries of the universe.” Wu Xiangping said in November.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 9:51 am on October 31, 2020 Permalink | Reply
    Tags: "Astronomers Chart Star Formation History- Glimpse Fate of the Universe", , , , , , , , Sky & Telescope   

    From Sky & Telescope: “Astronomers Chart Star Formation History- Glimpse Fate of the Universe” 

    From Sky & Telescope

    October 26, 2020
    Monica Young

    Astronomers have tallied how star-making material evolved over cosmic time — and predicted how long stars will keep forming before the universe goes dark.

    1
    ALMA has captured a gold mine of galaxies in the Hubble Ultra Deep Field: Those rich in carbon monoxide gas (which traces molecular hydrogen) have lots of star-forming potential (colored orange). Those galaxies imaged solely by Hubble appear in blue. This image from the ALMA Spectroscopic Survey (ASPECS) covers one-sixth of the full Hubble Ultra Deep Field.
    Credit: B. Saxton (NRAO / AUI / NSF) / ALMA (ESO / NAOJ / NRAO) / NASA / ESA Hubble.

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

    Astronomers have always been historians, looking back through time to piece together the story of the universe.

    Now, they have a new primary source in hand, a historical record of molecular hydrogen gas — the stuff that makes stars. The new observations enable not only a sweeping survey of the past, but a glimpse into our cosmic future.

    A History of Star Stuff

    Astronomers have spent decades charting the rise and fall of galaxies’ star formation over time. The stellar baby boom occurred about 10 billion years ago, at so-called “cosmic noon” [Annual Review of Astronomy & Astrophysics 2020]. During these early years of the universe, galaxies were bursting with newborn stars, sometimes birthing thousands per year. But rates have been falling ever since.

    To explore this rise and fall, astronomers went a step earlier in the process, charting not just the stars born but the material used to make them. Molecular hydrogen gas is cool enough that hydrogen atoms pair up — and it’s also cool enough to collapse into stars. Fabian Walter (Max Planck Institute for Astronomy, Germany) and colleagues used the Atacama Large Millimeter/submillimeter Array (ALMA) to survey the Hubble Ultra Deep Field (HUDF), one of the best-studied regions of the sky. The results of that survey appear in The Astrophysical Journal.


    ASPECS Project: ALMA and Hubble UDF

    ALMA is a 66-dish array in Chile capable of spying cool gas and dust in galaxies whose light has been traveling for up to 12 billion years. “This is one of the largest programs executed at ALMA,” Walter says, adding that the program used almost 200 hours of ALMA observing time. Along with other studies of the HUDF, ALMA provided the data Walter and colleagues needed to trace the flow of gas into galaxies and into stars.

    The gas that falls into galaxies is generally ionized, which means that the hydrogen atom is missing its electron. That gas has to cool, first recombining with electrons and then combining again into molecules, before it can form stars. Walter and colleagues are able to track both atomic and molecular gas to follow the flow of gas from the outermost reaches of a galaxy into its star-forming heart.

    “I think we already knew that’s how it has to work, but this paper nicely quantifies, perhaps for the first time, the global rate at which that happened, averaged over all galaxies, and over most of cosmic history,” says Mark Dickinson (NOAO), who was not involved in the study.

    3
    This diagram shows the flow of gas from the outermost reaches of a galaxy into its star-forming core. Feedback also occurs, tossing some gas back out again.Credit: Tumlinson et al. / Annual Reviews of Astronomy & Astrophysics 2018.

    The observations clearly show that galaxies never, at any one point in time, hold all the gas they need to make all their stars. The gas has to come from outside — the inflow of gas necessary for star formation has continued for all observed cosmic history.

    “Those are very challenging millimeter and radio measurements that were impossible not long ago,” Dickinson notes. “I think the Walter et al. paper sets an important benchmark for future analyses as new data are collected.”

    The Fate of the Universe

    As ever, examining the past also hints at the future. Star formation rates have declined ever since cosmic noon 10 billion years ago. The inflow of gas will only continue to decline, the researchers write: “The cosmic star formation rate density will continue its steady descent to the infinitesimal.”

    It’s a one-way street, Walter says: “I cannot think of a simple way to ‘reverse’ or ‘restart’ this trend.”

    The good news is that we have billions of years before the universe goes dark. And even as the influx of star-making material continues to decrease over the next 5 billion years, galaxies will continue making new stars with what they still receive. We’re hardly at the end of times just yet.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 8:26 am on September 17, 2020 Permalink | Reply
    Tags: "Study Suggests Jupiter Could Have 600 Moons", , , , , Sky & Telescope,   

    From University of British Columbia CA via Sky & Telescope: “Study Suggests Jupiter Could Have 600 Moons” 

    U British Columbia bloc

    From University of British Columbia CA

    via

    From Sky & Telescope

    September 8, 2020
    Govert Schilling

    From University of British Columbia CA
    Edward Ashton
    Matthew Beaudoin
    Brett Gladman

    New detections of candidate moons suggest that the king of planets could have hundreds of smaller satellites.

    1
    Ganymede and Europa, the largest and smallest of Jupiter’s four Galilean moons, cast their shadows on Jupiter. The newly discovered detections reported here are evidence of much smaller moons in farther-out orbits.
    Credit: Damian Peach.

    Jupiter could have some 600 moons measuring at least 800 meters (2,600 feet) in diameter, according to a team of Canadian astronomers. They will present their findings on September 25th at the virtual Europlanet Science Congress 2020. Most of the moons are in wide, irregular, and retrograde orbits.

    Over the past 20 years, astronomers have found dozens of small Jovian moons thanks to the advance of large digital cameras. Back in 2003, Scott Sheppard (Carnegie Institution of Science) already estimated that the number of irregular moons larger than a kilometer would probably be around one hundred.

    Now, Edward Ashton, Matthew Beaudoin, and Brett Gladman (University of British Columbia, Vancouver) have detected about four dozen possible new Jovian moons that are even smaller. Extrapolating from the sky area they have searched (about one square degree), they conclude that there could be some 600 of these tiny objects orbiting the giant planet.

    The team studied 60 archival 140-second exposures of a field close to Jupiter, all of them taken within a 3-hour period on September 8, 2010, with the 340-megapixel MegaPrime camera at the Canada-France-Hawai‘i Telescope on Mauna Kea. The astronomers digitally combined the images in 126 different ways, one for every possible combination of speed and direction at which a potential Jovian moon might move across the sky.

    CFHT MegaPrime camera.


    CFHT Telescope, Maunakea, Hawaii, USA, at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level.

    2
    This discovery image shows one of the brightest new candidate moons (preliminary designation: j22r94a24). The new moon is at the center of the image; stars appear as streaks due to the shift-and-stack process used to combine multiple exposures.
    Edward Ashton (University of British Columbia CA).

    This method revealed 52 objects down to magnitude 25.7, corresponding to diameters of some 800 meters. Seven of the brighter finds turned out to be known irregular satellites of Jupiter; the others are almost certainly retrograde Jovian moons, which orbit the planet in the direction opposite its rotation. A paper describing the results has been accepted for publication in The Planetary Science Journal, The Population of Kilometer-scale Retrograde Jovian Irregular Moons.

    If this sensitive one-square-degree “pencil-beam” search already yields 45 formerly unknown moons, the researchers estimate that the total number of satellites within this size range must be around 600. The current official number of Jovian moons is 79.

    Sheppard (whose team found 20 new satellites of Saturn last year) is not surprised by the new result. “We used a similar shift and stack technique for our Jupiter moon discoveries that were announced in 2018,” he says. “In our paper, we also mentioned detections that we could not confirm as moons, because we didn’t observe them for the months and years required to reliably determine their orbits.”

    3
    This diagram shows the orbits of Jupiter’s 79 confirmed moons. The planet’s prograde moons (purple, blue) orbit relatively close to Jupiter while its retrograde moons (red) are farther out. The newly discovered moons likely belong to the latter group. (Valetudo, a previously discovered moon marked in green, is an exception; it’s farther out but orbits prograde.) Credit: Carnegie Inst. for Science / Roberto Molar Candanosa.

    Likewise, the Canadian team cannot yet claim new discoveries for their 45 new detections, let alone for the extrapolated 600. “It takes a lot of large telescope time to get reliable orbits for these very small and numerous moons,” says Sheppard, “so one has to decide if that is scientifically valuable.”

    According to Ashton, there are currently no plans for follow-up observations of the new moons. “It would be nice to confirm them,” he says, “but there is no way to track them without starting from scratch.” However, the tiny moons will certainly be found again by future instruments like the Vera C. Rubin Observatory.

    Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes, altitude 2,715 m (8,907 ft).

    “They will then be linked back, so our observations will eventually be incorporated.”

    The new detections raise the question of how small an object can be and still be called a moon. “Eventually one descends to ring particles, and some kind of cutoff will be useful,” says Ashton. But Sheppard doesn’t believe we need “any more definition of what is a moon.” Anyway, he says, the International Astronomical Union will not name planetary moons smaller than one kilometer in size.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

    U British Columbia Campus

    The University of British Columbia CA is a global centre for research and teaching, consistently ranked among the 40 best universities in the world. Since 1915, UBC’s West Coast spirit has embraced innovation and challenged the status quo. Its entrepreneurial perspective encourages students, staff and faculty to challenge convention, lead discovery and explore new ways of learning. At UBC, bold thinking is given a place to develop into ideas that can change the world.

     
  • richardmitnick 8:25 am on September 12, 2020 Permalink | Reply
    Tags: "Astronomers Map Andromeda’s Halo" again, , , , , New research on the hot gas surrounding Andromeda shows that it’s likely already overlapping the Milky Way’s halo., Sky & Telescope   

    From Sky & Telescope: “Astronomers Map Andromeda’s Halo” 

    From Sky & Telescope

    September 10, 2020
    Monica Young

    1
    This illustration depicts what Andromeda’s gaseous halo might look like if it were visible to humans on Earth. At three times the size of the Big Dipper, the halo would be “easily the biggest feature on the nighttime sky,” per the NASA statement. (NASA, ESA, J. DePasquale and E. Wheatley (STScI), and Z. Levay (background image)).

    2
    This illustration shows the location of the 43 distant background quasars scientists used to probe Andromeda’s outermost regions. The purple shows an artist’s concept of what the hot gaseous halo might look like.
    NASA / ESA / E. Wheatley (STScI).

    Astronomers have observed 43 quasars in back of our sister galaxy, Andromeda, using the distant beacons to map its halo of hot gas.

    If it’s clear tonight, you might go outside and find the Andromeda Galaxy between the Cassiopeia and Andromeda constellations. Our galactic sibling is currently 2.2 million light-years away, so it appears as a spindle-shape bit of fuzz that requires dark skies to see. A few billion years from now, our descendants will have an even better view, as we’re headed almost straight for it.

    Even today, though, new observations show the two galaxies are already “touching.” New research on the hot gas surrounding Andromeda shows that it’s likely already overlapping the Milky Way’s halo.

    Milkdromeda -Andromeda on the left-Earth’s night sky in 3.75 billion years-NASA.

    “We know galaxies rotate,” says Roeland van der Marel (Space Telescope Science Institute), who led a team in publishing the results in The Astrophysical Journal, 2019. But, he adds, this rotation has never been measured in three dimensions and on the level of individual stars. “But with less than two years of Gaia data, we were able to measure the 250 million-year revolution of Andromeda.” To put this in perspective, van der Marel says, the stars that Gaia was staring at move at the same speed that a human hair would grow as seen at the distance of the Moon.

    Hot Gas Hiding in Plain Sight

    Every large galaxy is surrounded by gas so hot (between 10,000 and 100,000 degrees) that it hasn’t settled yet. But this gas is hard to see — it doesn’t emit much light itself, so astronomers see it mostly as part of foreground “clouds” that absorb light from background sources.

    In The Astrophysical Journal, September 1st, Nicolas Lehner (University of Notre Dame) and colleagues used an unprecedented number of such background sources to map the hot halo around Andromeda.

    Quasars are the bright centers of galaxies, where black holes devour gas — they’re luminous enough to shine from the earliest ages of the universe. Nevertheless, they’re points of light, and most foreground galaxies are quite small on the sky. So, despite the trillions of galaxies in our cosmos, there aren’t typically a lot of quasars in back of any one galaxy — maybe one or two.

    But Andromeda is close enough — and therefore appears large enough — that Lehner and colleagues identified and observed 43 distant quasars near it on the sky. (This study extends previous research by the same team using 18 quasars [The Astrophysical Journal]). Using the Hubble Space Telescope, the researchers measured spectra of these background quasars, essentially taking 43 different “core samples” through the halo to map out its structure.

    Andromeda is a big one and has had its share of galactic scrapes. So it’s not surprising that its halo is a jumbled mess. But with the new map, Lehner’s team sees the halo essentially has two distinct regions: a disturbed inner shell and a smoother outer section. The outer section represents gas leftover from the galaxy’s formation; the inner shell has been stirred up in the more recent past, likely by supernovae in the galaxy’s disk.

    A Common Halo

    The team also found that the halo is huge — it extends almost 2 million light-years from the galaxy’s center. If we could see it, it would be three times the width of the Big Dipper!

    If the Milky Way’s halo has a similar size, and there’s no reason to think it shouldn’t, then the two halos actually overlap in space. That’s not to say that their collision has begun: The halo gas is so spread out, and the relative velocities so low, that the gas doesn’t collide per se. Instead, the Milky Way and Andromeda might share a common halo, as shown in simulations.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 12:59 pm on September 2, 2020 Permalink | Reply
    Tags: "Twinkling Quasar Hints at Mysterious Nearby Plasma Cloud", , , , , , Sky & Telescope, The discovery is the first published scientific result obtained with the new wide-angle Apertif receivers (Aperture Tile In Focus) on ASTRON’s venerable 14-dish Westerbork Synthesis Radio Telescope.   

    From Sky & Telescope: “Twinkling Quasar Hints at Mysterious Nearby Plasma Cloud” 

    From Sky & Telescope

    September 1, 2020
    Govert Schilling

    Radio observations have turned up evidence of a cloud of hot plasma near — or even in — the solar system. But its distance estimate is still up for debate.

    1
    Discovery radio image of the new rapidly twinkling quasar J1402+5347 (bottom); the spiral galaxy M101 is at the top. The radial spikes are an artifact caused by the source’s rapid variability in combination with the east-west orientation of the Westerbork interferometer. Credit: Tom Oosterloo / ASTRON.

    Radio astronomers have detected a cloud of hot plasma at the edge of the solar system, and no one has a clue about its nature or origin.

    Researchers didn’t observe the mystery cloud directly. Instead, they saw its effect on the radio waves of a background quasar known as J1402+5347. Its presence caused the quasar’s light to flicker on a timescale of minutes. “It’s a spectacular twinkler, and a very nice surprise,” says Mark Walker (Manly Astrophysics, Australia), who studies intra-hour variability of quasars but wasn’t involved in the new work.

    Until recently, astronomers knew of three rapidly twinkling quasars, whose scintillations suggested the presence of plasma clouds at distances of a few tens of light-years. But the new cloud is much closer, says study lead Tom Oosterloo (ASTRON Netherlands Institute for Radio Astronomy).

    Interstellar radio scintillation produces a speckle pattern, comparable to the speckle pattern in the optical image of a star that results from atmospheric turbulence. As Earth moves through that pattern, astronomers observe rapid brightness variations. “From the observed twinkle frequency of J1402+5347,” Oosterloo says, “we deduce a distance of just 0.8 light-years for the plasma screen, which is within the solar system’s Oort cloud.”

    2
    Schematic of radio waves from a quasar traveling through a plasma cloud and arriving at Apertif.
    ASTRON / Credit: Studio Eigen Merk.

    The discovery is the first published scientific result obtained with the new wide-angle Apertif receivers (Aperture Tile In Focus) on ASTRON’s venerable 14-dish Westerbork Synthesis Radio Telescope. Apertif increased the instrument’s field of view by a factor of 40, making it much easier to find rare sources.

    The plasma cloud, thought to be at least a few billion kilometers (several astronomical units) across, could be an interloper from interstellar space. Or it could be some kind of remnant from the formation of the solar system, says Oosterloo. “That would be really exciting.”

    However, Walker isn’t so sure about the cloud’s estimated proximity, which is based on a simple, idealized model. Each of the previously known twinkling quasars appeared to be associated with a nearby hot star (Vega, Spica, and Alhakim or Iota Centauri, respectively), suggesting that the intervening plasma was somehow expelled by the star.

    As Oosterloo and his colleagues discuss in their Astronomy & Astrophysics paper, the new quasar’s sky position is close to Alkaid (Eta Ursae Majoris), which is just over 100 light-years from Earth. “It’s very unlikely that we’d get a random coincidence between [a twinkler] and a hot star like Alkaid,” says Walker. “The chances are less than one in 1,000 for a match as close as this — so my guess is that they are indeed physically related.”

    3
    Some of the fourteen 25-meter dishes of the Westerbork Synthesis Radio Telescope in the Netherlands. The white boxes in the focal points of the antennas contain the new wide-angle Apertif receivers. Credit:
    ASTRON.

    But according to Oosterloo, that would imply an improbably compact and extremely elongated plasma cloud. Moreover, since the team serendipitously found the new intra-hour variable quasar in April 2019, they’ve discovered 10 more of these rare sources that do not seem to be associated with nearby stars, though the intervening plasma appears to be many light-years away in these newer cases.

    Radio astronomer Hayley Bignall (CSIRO, Australia), who was also not involved in the new study, says she would “naively agree with the arguments the authors make for a very nearby plasma screen. On its own, I would say the case for the very small distance is compelling, but not 100% convincing.” Follow-up observations at other wavelengths and the study of additional twinkling quasars would help strengthen or refute the claim, Bignall says.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 4:04 pm on August 28, 2020 Permalink | Reply
    Tags: "See the Invisible: A Gallery of Magnetic Fields", , Invisible magnetic fields play a role in everything from star formation to galaxy evolution to black hole phenomena. But astronomers still debate what that role is., NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA), Sky & Telescope   

    From Sky & Telescope: “See the Invisible: A Gallery of Magnetic Fields” 

    From Sky & Telescope

    August 24, 2020
    Monica Young

    Invisible magnetic fields play a role in everything from star formation to galaxy evolution to black hole phenomena. But astronomers still debate what that role is.

    The HAWC+ instrument, a far-infrared imager and polarimeter aboard the Stratospheric Observatory for Infrared Astronomy (SOFIA), is helping portray magnetism’s role in a beautiful way. Flying above much of Earth’s atmosphere aboard a modified Boeing 747, HAWC+ has measured the polarization of far-infrared radiation, gauging how well the light waves are aligned with each other.

    NASA/DLR SOFIA modified Boeing 747 aircraft.

    NASA SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera.

    Usually, light waves are not aligned with each other at all. But dust grains line up in the space between stars due to interstellar magnetic fields, so the infrared radiation dust emits is polarized. HAWC+ thus enables astronomers to infer the alignment and strength of the magnetic field.

    1
    This composite image of the Serpens South Cluster shows the magnetic fields, as observed by SOFIA, as streamlines over an image from the Spitzer Space Telescope. The strong, dense flow of gas in the dark filament at lower left has dragged the magnetic field lines so that they run along the length of the filament. Credit NASA/DLR SOFIA / T. Pillai / J. Kauffmann; NASA / JPL-Caltech / L. Allen.

    NASA/Spitzer Infrared telescope no longer in service.

    In the August 20th Nature Astronomy, Thushara Pillai (Boston University and Max Planck Institute for Radio Astronomy, Germany) and colleagues used HAWC+ to measure the magnetic fields in a stellar nursery known as Serpens South. Denser filaments permeate such clouds, channeling gas into young star clusters.

    Magnetic fields also permeate star-forming clouds — but what they do there remains unclear, as the field strength is 10,000 times weaker than Earth’s magnetic field and therefore difficult to measure.

    Previous measurements using the Planck satellite have shown that the magnetic field tends to run parallel to lower-density filaments and perpendicular to higher-density filaments, suggesting that magnetism might moderate star formation by counteracting the pull of gravity.

    ESA/Planck 2009 to 2013.

    However, the new HAWC+ measurements taken by Pillai’s team indicate that along the densest, darkest filaments in Serpens South, the magnetic fields once again run parallel. “In some dense filaments the magnetic field succumbs to the flow of matter and is pulled into alignment with the filament,” Pillai explains. In these regions, the weakly magnetized gas is feeding the growth of young stellar clusters like a conveyor belt.

    This is only the latest result to come out of HAWC+. A selection of other composite images below visualize the magnetic field lines in the star-forming Orion Nebula, the Cigar Galaxy (M82), and in the region around our galaxy’s supermassive black hole.

    3
    Streamlines overlaid on an image of the Orion Nebula show the magnetic field morphology determined from 53-micron polarization maps obtained with SOFIA’s HAWC+ instrument. Here, the magnetic fields appear to run counter to gravity, slowing down star formation. The European Southern Observatory’s Very Large Telescope took the background image, which shows the Trapezium stars in white and the Becklin-Neugebauer object in pink. NASA/DLR SOFIA / D. Chuss / L. Proudfit.

    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.

    4
    A composite image of the Cigar Galaxy (Messier 82) shows the magnetic field detected by the HAWC+ instrument onboard SOFIA. Displayed as streamlines, the magnetic field appears to follow the bipolar outflows (red) generated by the intense starbirth in the center of the galaxy. Read more about the result in Tracing the Cigar Galaxy’s Superwind. The image combines visible starlight (gray) and a tracing of hydrogen gas (red) observed from the Kitt Peak Observatory, with near-infrared and mid-infrared starlight and dust (yellow) observed by SOFIA and the Spitzer Space Telescope [above].
    NASA/DLR SOFIA / E. Lopez-Rodiguez; NASA / Spitzer / J. Moustakas et al.

    Kitt Peak National Observatory of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft).

    4
    A far-infrared image of the galactic center of the Milky Way taken by two instruments aboard the SOFIA observatory (color image) traces dusty arcs that surround and possibly feed the supermassive black hole at the center of our Milky Way Galaxy. Streamlines show the magnetic field morphology from SOFIA HAWC+ polarization maps. The magnetic field here is strong enough to counter the gas’s turbulence, and the field lines appear to provide channels for gas flow (from the outside in or vice versa). The background star field is from the Hubble Space Telescope.
    NASA/ DLR SOFIA/D. Dowell/W. Reach/L Proudfit.

    The SOFIA 106-inch telescope and instruments image infrared light from on high, flying aboard a modified Boeing 747SP jetliner. Unfortunately, operations have been suspended due to the ongoing COVID-19 pandemic; however, the SOFIA science center remains active and astronomers continue to work with the data that SOFIA has already collected.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 1:12 pm on July 31, 2020 Permalink | Reply
    Tags: "Our Unexpectedly Smooth Universe May Point to New Physics", , , , , Sky & Telescope   

    From Sky & Telescope: “Our Unexpectedly Smooth Universe May Point to New Physics” 

    From Sky & Telescope

    July 31, 2020
    Govert Schilling

    The latest data release from a survey of 31 million galaxies reveals that our universe is even smoother than we thought it was.

    The universe is smoother than expected.

    The latest data release from the Kilo-Degree Survey (KIDS) confirms earlier indications that the current distribution of gravitating matter is less clumpy than predicted by the standard model scientists use for cosmology.

    Using the 268-megapixel OmegaCAM on the 2.6-meter Very Large Telescope’s Survey Telescope at Cerro Paranal in Chile, the European KIDS collaboration has studied 31 million remote galaxies in two large swaths of sky totaling 1,006 square degrees.

    ESO OmegaCAM on VST at ESO’s Cerro Paranal observatory,with an elevation of 2,635 metres (8,645 ft) above sea level

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light.
    with an elevation of 2,635 metres (8,645 ft) above sea level

    Intervening matter (both visible and dark) slightly bends the light from these galaxies via weak gravitational lensing, producing tiny distortions in their shapes (see Sky & Telescope’s September 2016 issue). Precise analysis of this cosmic shear reveals how the matter is distributed.

    2
    A zoom-in on a part of the KIDS map, showing a patch of universe approximately 1.5 x 1 billion light-years across. In this false-color image, high-density regions are shown in yellow and low-density regions are in pink. Credit: B.Giblin / K.Kuijken / KIDS team.

    The European Planck mission mapped the Big Bang’s afterglow, known as the cosmic microwave background [CMB], and scientists have modeled the minute fluctuations in the glow’s temperature using the standard cosmology, which includes dark energy and dark matter.

    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    This model, sometimes referred to as ΛCDM, predicts that galaxies and galaxy clusters should group together a certain amount in the present-day universe.

    Lamda Cold Dark Matter Accerated Expansion of The universe http scinotions.com the-cosmic-inflation-suggests-the-existence-of-parallel-universes
    Alex Mittelmann, Coldcreation

    However, the KIDS map yields a measurement of this clustering, known as S8, that is 8.3% smaller than expected. The results have been submitted for publication in Astronomy & Astrophysics, and are currently available in preprint form [link is unclear].

    According to KIDS project lead Koen Kuijken (Leiden Observatory, The Netherlands), the team has taken care to minimize all potential systematic errors, both in the observations and in their analysis. “Compared to our 2016 data release [based on half as much data], the difference with the ΛCDM predictions is a bit smaller, but the error bars are much tighter,” he says.

    The statistical significance of the result is 3 sigma, which means there’s only a 1 in a 1,000 chance that the findings could be caused by scientists having looked at a particularly unusual part of the universe, according to team member Benjamin Joachimi (University College London) in a press statement.

    The ΛCDM model also predicts a value for the Hubble constant — a measure of the current expansion rate of the universe — that is not borne out by measurements of objects in relatively nearby galaxies (see the June 2019 issue of Sky & Telescope). New results continue to extend that cosmic controversy. The two issues may be related, says Kuijken, but it’s too early to say if they really point to a fundamental problem with the standard cosmological model. “Maybe it’s just a matter of relatively small modifications.”

    But according to theorist Avi Loeb (Harvard University), progress in physics traditionally follows anomalies. “If the anomaly in S8 and the Hubble constant stands the test of time, then both may imply new physics,” he explains. “It would be attractive to kill two birds with one stone. So far, however, I have not seen an elegant theoretical idea that can account for the Hubble tension, let alone the anomaly in S8.”

    Analysis of the full 1,350-square-degree dataset of the KIDS survey is now underway; the fifth and final data release is expected next year. Another cosmic-shear project, the Dark Energy Survey has just published results from their first survey year [Dark Energy Survey Year 1 Results: Constraining Baryonic Physics in the Universe ( https://arxiv.org/abs/2007.15026 )], yielding a clustering parameter 5.5% smaller than the ΛCDM value. A third project with the Japanese Hyper Suprime-Cam Survey is also expected to publish results within the next few months.

    NAOJ Subaru Hyper Suprime-Cam

    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    Starting three or so years from now, the European Space Agency’s Euclid mission and the Vera C. Rubin Observatory will greatly improve on current surveys, both in sensitivity and in sky coverage. Eventually, it will become clear whether or not we’ll have to discard our cherished theoretical model of the universe.

    ESA/Euclid spacecraft depiction

    Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    “The history of physics teaches us modesty,” says Loeb. “Sometimes nature is much more imaginative than we are.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 3:33 pm on July 16, 2020 Permalink | Reply
    Tags: "European Solar Orbiter Takes Closest-ever Images of the Sun", Sky & Telescope,   

    From Sky & Telescope: “European Solar Orbiter Takes Closest-ever Images of the Sun” 

    From Sky&Telescope

    July 16, 2020
    Monica Young

    ESA/NASA Solar Orbiter depiction

    The first images to be released from the European Space Agency’s Sun-imaging spacecraft show intriguing “campfires” that could help explain a solar mystery.

    Another spacecraft is joining a growing armada of Sun-observing satellites. The European Space Agency’s Solar Orbiter has just made its first close pass by the Sun on June 15th, which took it to within 77 million km (48 million miles), or roughly twice as close to the Sun as Earth is. This first perihelion, which occurred before the Solar Orbiter enters full science operations, has already provided stunning images of the Sun’s outer atmosphere.

    The Solar Orbiter does not go nearly as close to the Sun as NASA’s Parker Solar Probe does, but for good reason.

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker

    The environment that Parker encounters when it comes within 9 solar radii of the Sun’s visible surface is too harsh for any existing camera to directly image the Sun. Solar Orbiter’s distance enables its multiple cameras, which peek out peepholes in the spacecraft’s heat shield, to take in the full disk of the Sun and zoom in to capture details in its atmosphere.

    1
    This mosaic of images shows the full disk of the Sun as viewed by the Extreme Ultraviolet Imager (EUI) and the Polarimetric and Helioseismic Imager (PHI). The yellow images in the top row shows EUI’s view at 17 nanometers, while the red views in the right column show EUI’s view at 30 nm. (Both are false-color images, because the wavelengths imaged are outside the visible range.) While the yellow images show the outermost atmosphere, the solar corona, the red images show a lower layer of the atmosphere named the transition region. The middle panel combines EUI images with ones from the NASA’s Solar Dynamics Observatory.

    NASA SDO

    The left images show magnetic field maps of the Sun derived from PHI data. Finally, the bottom middle image shows the Sun in visible light, sans sunspots.
    Solar Orbiter / EUI Team; PHI Team / ESA & NASA

    First Images and “Campfires”

    The mission has just released the spacecraft’s first images, captured on May 30th, just before perihelion. Taken for calibration purposes, these extreme-ultraviolet images show a quiet area of the Sun, where nothing special was expected to be happening. But the images held a surprise for researchers: Small flares nicknamed “campfires” flicker all over the Sun’s corona.

    “The Sun might look quiet at the first glance, but when we look in detail, we can see those miniature flares everywhere we look,” says David Berghmans (Royal Observatory of Belgium), principal investigator of the Extreme Ultraviolet Imager (EUI), which took the images.

    These mini-flares might play a role in heating the solar corona, the outer atmosphere which is counterintuitively 200 times hotter than the Sun’s visible surface. While there’s no doubt that the Sun’s writhing magnetic fields provide the energy to heat the corona, how the magnetic energy is converted to heat has remained a mystery for decades. The heat from the combined sparks of small but abundant mini-flares (sometimes termed nanoflares) could be responsible.

    The video below captures the flares with details as small as 400 kilometers across. It represents the closest views we’ve ever seen of the Sun.

    (You might notice a small dust bunny in the upper right of the video. “We joke that is our exobiology experiment,” Berghmans says. “In fact it’s a sensor defect.” The defect has earned a variety of nicknames, including “the tardigrade” and “gummy bear.” It even appears to move, due to processing to remove shakiness in the images. In the future, image processing will also remove the defect itself by interpolating from nearby pixels.)


    But it may be too early to draw the comparison between the campfires seen here and the hypothesized nanoflares. The team members must still combine the data from the many instruments the Solar Orbiter carries. And others offer caution as well. “The campfires have been seen before in many guises,” says Hugh Hudson (University of Glasgow, UK). “Associating campfires with nanoflares? I think this is a non-starter simply because of the very nice intermittency that they exhibit, both in space and in time.”

    3
    The Extreme Ultraviolet Imager (EUI) on ESA’s Solar Orbiter spacecraft took these images on 30 May 2020. They show the Sun’s appearance at the extreme ultraviolet wavelength of 17 nanometers. Images at this wavelength reveal the upper atmosphere of the Sun, the million-degree solar corona. EUI has two imagers that take full-disk images (top left) and high-resolution close-ups, respectively.
    Solar Orbiter / EUI Team (ESA & NASA); CSL / IAS / MPS / PMOD / WRC / ROB / UCL / MSSL

    Hudson instead sees more promise in other data the Solar Orbiter offers. “What is very new and very important with Orbiter (not counting its polar views) is just the stereoscopy at such high resolution,” he explains. For the first time, Solar Orbiter will help untangle the three-dimensional layers of the Sun’s atmosphere, especially when working together with other solar observatories on or around Earth.

    What’s Next for the Solar Orbiter

    Within two years, Solar Orbiter will fly within ¼ a.u. of the Sun’s visible surface, resulting in images twice as sharp as the ones released today. And the scientists are only beginning to understand the images that the instruments produce. Berghmans expects that changes to image processing and even spacecraft steering will also improve the images over time.

    Technically, the ground-based Daniel K. Inouye Solar Telescope has better eyesight than Solar Orbiter; its first-light images released in January have a resolution of 30 km. But while the Inouye Telescope is limited to viewing visible light that makes it through Earth’s atmosphere, Solar Orbiter is seeing ultraviolet light and X-rays that our atmosphere blocks.

    Daniel K. Inouye Solar Telescope, DKIST, atop the Haleakala volcano on the Pacific island of Maui, Hawaii, USA, at an altitude of 3,084 m (10,118 ft).

    Solar Orbiter’s viewpoint is also decidedly unique. All views of the Sun — whether from Earth or from Earth-orbiting or even Sun-orbiting satellites — have come from within the ecliptic plane, the plane in which the planets orbit the Sun. The Solar Orbiter will provide the first views of the Sun from a polar perspective. The orbiter flies in an increasingly inclined orbit that will ultimately take it 33° above the equator, giving the spacecraft a polar view of the Sun that we’ve never seen before.

    4
    This diagram depicts the Solar Orbiter’s journey from 2020 to 2030, including flybys past Venus and Earth. Its orbits gradually approach the Sun while simultaneously altering the orbit to a more inclined angle that allows a view of the Sun’s poles. ESA.

    The Solar Orbiter carries 10 instruments, five of them peeping out through the heat shield. Other instruments directly sample the solar wind’s properties from behind the heat shield. They also measure the magnetic field of both the solar wind and the Sun where it came from. Ultimately, the goal is to combine data from all 10 instruments to understand the origin of the solar wind and how it drives space weather near Earth.

    While these first images show huge promise for the mission, researchers and the public alike will have to be patient. Full science operations won’t begin until March 2022. And the spacecraft won’t start probing the solar poles until 2025, with its best polar views coming in 2027. Nevertheless, the campfire discovery already points to what we can gain by imaging the Sun from close up.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 8:43 am on July 8, 2020 Permalink | Reply
    Tags: "Two Bright Supernovae Light Up Nearby Galaxies", , , , , Sky & Telescope   

    From Sky & Telescope: “Two Bright Supernovae Light Up Nearby Galaxies” 

    From Sky & Telescope

    July 7, 2020
    Bob King

    Two bright new supernovae are now within the range of amateur telescopes in the western sky at nightfall.

    1
    Supernova 2020nlb in the galaxy M85 in Virgo was a 17th-magnitude blip at discovery but has grown brighter each night. Now at magnitude 12.2 (July 7th), it’s bright enough to see in a 6-inch telescope. M85’s supernova is currently almost a full magnitude brighter than the 13.1-magnitude field star immediately to its northeast. The supernova sits 1.0″ east and 43.2″ north of the core. North is up.
    Gianluca Masi.

    If you want to see a supernova in your lifetime, why wait around for Betelgeuse to blow up? If you have a 6-inch telescope and access to a dark sky, you can see one right now. Two actually. Both are visible in the western sky at nightfall in the neighboring constellations Virgo and Coma Berenices.

    The first of the pair, dubbed 2020nlb, was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on June 25th in the 10th-magnitude galaxy M85.

    ATLAS telescope, First Asteroid Terrestrial-impact Last Alert system (ATLAS) fully operational 8/15/15 Haleakala , Hawaii, USA, Altitude 4,205 m (13,796 ft)

    Located in Coma Berenices 60 million light-years from Earth, M85 is an elliptical galaxy a quarter again as large our Milky Way. The “M” stands for Charles Messier, an 18th century French astronomer who compiled a list of galaxies, star clusters and nebulae he stumbled on during searches for his favorite prey, comets.

    2
    Located just 3.3″ west and 8″ north of the core, the bright supernova 2020nvb appears “stuck” to NGC 4457’s bright nucleus. North is up. Gianluca Masi.

    Japanese amateur and prolific supernova hunter Koichi Itagaki nabbed SN 2020nvb on July 1 in NGC 4457, a spiral galaxy in Virgo located about 55 million light-years away. Each of these newly discovered supernovae occurred in a close binary system where a tiny, superdense white dwarf star orbits a normal star. The dwarf is only about the size of Earth, but its matter is packed so tightly the object has nearly the same mass as the Sun. You’d need a massive crane to lift even a thimbleful!

    3
    Artist’s view of a white dwarf, surrounded by an accretion disk of material pulled off its larger companion (left). The hot gas funnels down from the disk to the dwarf’s surface where it accumulates until it initiates a runaway fusion process that destroys the star (right). ESO.

    The dwarf’s powerful gravity siphons material from its companion onto its surface until the added weight and pressure of the stolen material initiates a runaway nuclear fusion within the dwarf and boom! — it explodes cataclysmically as a supernova.

    Like breakfast cereals, supernovas come in a variety of types but are broadly divided into Type Ia (white dwarf explosions in close pairs) and Type II (massive star blasts like Betelgeuse). Both 2020nlb and 2020nvb are Type Ia supernovae, among the brightest “candles” in the universe. In fact, the most luminous Type Ia supernovae routinely outshine their entire host galaxy! Betelgeuse is a standalone, gigantic star. One day it will run out of nuclear fuel, halt fusing new elements, and then collapse and explode as a supernova as bright as the gibbous Moon.

    The M85 supernova quickly brightened from magnitude 16.8 at discovery to 12.2 on July 7 and may still be getting brighter. The NGC 4457 supernova is even brighter at magnitude 11.9 and located a little northwest of the center of the galaxy’s nucleus.

    Star-hop to a Supernova

    4
    This wide-view map will orient you. Key guide stars are Denebola in the tail of Leo and Porrima, Eta, and Epsilon Virginis — all visible with the naked eye. See detailed map below. Stars are shown to magnitude 6 and brighter galaxies are included for reference. Stellarium.

    Now that the moon is past full, it’s on its way out of the evening sky, so you’ll have the darkness you’ll need to spot these distant explosions in smaller scopes. I encourage you to start looking for the pair as soon as it gets dark, when they’re highest in the sky and least affected by the atmosphere.

    Begin at Denebola, an obvious 2nd-magnitude star about two fists (20°) high in the western sky at twilight’s end, and star hop to M85 using the chart below as guidance. Or start at Epsilon Virginis. Then use the photo to identify the supernova. To reach NGC 4457, start star-hopping at either Porrima or Eta Virginis in Virgo.

    6
    This more detailed map shows stars to magnitude 9. The yellow, arrowed lines are suggested star-hopping routes for you to try out . . . or pick your own.
    Stellarium with additions by the author.

    Use your lowest magnification while star-hopping. Once you’ve arrived at each galaxy increase the power to 100x or higher to pick out the supernovae. Then let your imagination go. Picture each point of light as a star in the process of self-destruction, one of the most powerful and creative acts in the universe.

    Creative? You bet. Supernovae explosions seed interstellar space with lots of elements, including familiar ones like iron, nickel, lead and gold. All that material regathers into great clouds of gas and dust called nebulae, within which are born new generations of stars and planets . . . and well, who knows what else, including life.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 9:53 am on June 6, 2020 Permalink | Reply
    Tags: "First Discoveries of a Pro-Am Exoplanet Survey", , , , , Galactic Plane eXoplanet (GPX) Survey, Paul Benni's Acton Sky Portal a residential private observatory, Sky & Telescope   

    From Sky & Telescope: “First Discoveries of a Pro-Am Exoplanet Survey” 

    SKY&Telescope bloc

    From Sky & Telescope

    June 5, 2020
    Steve Murray

    Amateur astronomer Paul Benni and researcher Artem Burdanov (MIT) reported three new discoveries — a hot Jupiter, a brown dwarf, and an eclipsing binary system — at this week’s virtual meeting of the American Astronomical Society.

    Using readily available commercial equipment, the pair teamed up to survey the sky for exoplanets. It began a few years ago when Burdanov initiated a pilot survey, originally called the Kourovka Planet Search (KPS), with colleagues from the Ural Federal University in Russia. They looked for exoplanets transiting across their stars, searching for the resulting dips in starlight, just as NASA’s Kepler and TESS space telescopes have done.

    Planet transit. NASA/Ames.

    But the survey carried a twist: Burdanov aimed to survey regions of the sky other programs had skipped, namely the crowded plane of our galaxy’s disk.

    1
    The Acton Sky Portal, a residential private observatory, has the RASA 11 survey telescope (left) and a Celestron C14 narrow-field telescope for follow-up observations (right).Credit: Paul Benni

    Benni had been assisting the KPS team with follow up observations since 2013 from his home near Boston, Mass. When Burdanov moved to the University of Liege, Benni continued the project, now termed the Galactic Plane eXoplanet (GPX) Survey, with an upgraded system that included Burdanov’s enhanced image-processing software. The GPX system consisted of a 279-mm (11-in.) Celestron RASA wide-field survey telescope and an FLI ML16200 camera. Benni operated the entire survey from his home observatory, which he calls the Acton Sky Portal.

    To access the galactic plane, which is crowded with stars, GPX trades large sky coverage for high resolution: The system has about 2 arcseconds/pixel, compared to the 4 and 20 arcseconds/pixel for the wider-field Kepler and TESS space telescopes, respectively.

    NASA/Kepler Telescope, and K2 March 7, 2009 until November 15, 2018

    NASA/MIT TESS replaced Kepler in search for exoplanets

    “Other surveys tend to avoid [the galactic plane] or have difficulties in finding transit signals there, as stars tend to blend together in images,” Benni explains. The trade-off also allowed the astronomers to focus on fainter stars, of magnitude 11 to 15. “Other surveys were looking at brighter stars,” adds Benni. “We tried to image a little beyond that to catch something they missed.”

    The Discoveries

    2
    GPX discovered a hot Jupiter around a host star similar to the Sun, shown here in an artist’s illustration. Credit: Kirill Ivanov, Irkutsk State University

    Their first confirmed detection came in 2015, back when the duo was still experimenting with the prototype Kourovka equipment. The team pointed the telescope at a small, randomly selected field near Ursa Major for a few months, accumulate 115 hours’ worth of data, revealing KPS-1b, a transiting hot Jupiter. “The discovery was a fortuitous one,” says Benni. “My son called KPS-1b the ‘lucky duck’ planet.” The find was later validated using radial velocity methods.

    KPS-1b is similar to Jupiter in mass and radius but orbits its 13th-magnitude host star every 1.7 days. “The discovery of KPS-1b inspired us to upgrade the camera and add multiple fields to the surveying capability,” Benni says. “That grew into the GPX system.”

    Using the revamped GPX setup, the team made its second discovery in 2016. GPX-1b, a brown dwarf 20 times Jupiter’s mass orbiting a 12th-magnitude star slightly more massive than the Sun. The star is rotating quickly, which suggests it’s young, perhaps only about 270 million years old.

    The GPX-1b work demonstrated the value of the GPX survey’s unique design and methods: When TESS launched and imaged the same region of the sky, the host star GPX-1 blended with a brighter, 9th-magnitude star less than an arcminute away, and TESS didn’t detect the transits of the brown dwarf companion.

    3
    GPX has a higher resolution than the TESS space telescope (2 arcseconds/pixel instead of 20.25 arcseconds/pixel), enabling it to tease apart the GPX-1 host star from a neighboring star. This in turn allowed GPX to capture the brown dwarf’s transits across GPX-1. Credit: Artem Burdanov and Paul Benni

    Their most recent discovery [MNRAS] came from data collected in 2018: GPX-TF16E-48 is a 15th-magnitude pair of stars, a white dwarf and K-type main sequence star that orbit each other every 7.1 hours. The orbit is edge-on as seen from Earth, making this an eclipsing binary, but it’s a tricky one to spot as the eclipses are only 10 minutes long. Follow-up observations revealed the white dwarf is possibly siphoning gas off its stellar companion and could begin to nova in about 9 million years.

    4
    In the system dubbed GPX-TF16E-48, a white dwarf and K-type main-sequence star orbit each other. The white dwarf appears to be pulling material off its companion, suggesting the pair could go nova in several million years.Credit: Kirill Ivanov, Irkutsk State University

    GPX shows the potential of professional and amateur astronomers to work together, using commercially available equipment to make discoveries that even world-class instruments might miss.

    Further publications on their work are pending. The work continues and, as Benni says, “we keep going.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
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