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  • richardmitnick 10:40 am on May 24, 2021 Permalink | Reply
    Tags: "Record-Setting Flare Spotted on the Nearest Star to the Sun", , , , , , Proxima Centauri,   

    From University of Colorado Boulder (US) via Eos: “Record-Setting Flare Spotted on the Nearest Star to the Sun” 

    U Colorado

    From University of Colorado Boulder (US)

    via

    AGU
    Eos news bloc

    Eos

    5.24.21
    Katherine Kornei

    1
    An enormous stellar flare erupts from Proxima Centauri in this artist’s representation. Credit: S. Dagnello, National Radio Astronomy Observatory (US)/Associated Universities Inc (US)/National Science Foundation (US).

    As stellar neighbors go, the Sun is a pretty good one—it occasionally produces a sizeable solar flare, but mostly, it leaves Earth well enough alone. The Proxima Centauri solar system isn’t so lucky, however: Blasts of electromagnetic radiation from Proxima Centauri, the next nearest star to our own, can be potentially lethal to nearby planets.

    Researchers recently spotted the brightest stellar flare ever detected from Proxima Centauri. That flare might have contributed to stripping away the atmosphere of one of its planets, a roughly Earth mass world that potentially hosts liquid water on its surface.

    Destroyer of Atmospheres

    Proxima Centauri is located 4.2 light-years away, yet it’s much too faint to see with the naked eye. (Polaris, the North Star, is more than 400 light-years distant, for comparison.) Proxima Centauri’s faintness stems from its low mass—it’s what astronomers refer to as an M dwarf star, defined as having a mass between roughly 10% and 50% the mass of the Sun. M dwarf stars are the most common stars in the Milky Way, but they come with a reputation, said Meredith MacGregor, an astronomer at the University of Colorado Boulder (US). “M dwarfs are vastly more active than the Sun.”

    That means they regularly emit stellar flares, blasts of electromagnetic radiation launched by their host star’s magnetic field. These streams of photons can be destructive, said MacGregor. When high-energy ultraviolet radiation collides with a planet’s atmosphere, it can disassociate molecules like water and ozone, splitting them into their constituent atoms. Some of those lighter atoms can then drift away and escape. “You can basically erode away the atmosphere of a planet,” said MacGregor.

    And They’re Off!

    In 2015, unbeknownst to earthly observers, Proxima Centauri let loose an enormous flare. The photons streamed through the Proxima Centauri solar system—with its two known planets—and continued out into interstellar space.

    A little more than 4 years later, MacGregor and her colleagues were observing Proxima Centauri using up to nine research telescopes simultaneously, five on the ground and four orbiting Earth. (Such coordinated observing is an astronomical tour de force, and it required a whole lot of communication among different observing facilities, said MacGregor.) On 1 May 2019, the team spotted a whopper of a flare. “This star is brightening in the ultraviolet by a factor of 14,000 in just a couple of seconds,” said MacGregor. “That challenges our picture of flaring.”

    It’s the brightest stellar flare ever detected from Proxima Centauri and about 100 times brighter than the largest flares produced by the Sun, MacGregor and her collaborators deduced. This event is a record setter, said MacGregor, but it’s probably not unique. “The star is doing this very frequently.”

    Similarities Across the Spectrum

    he researchers made a surprising discovery: The flare behaved remarkably similarly in observations at millimeter wavelengths (in the radio part of the electromagnetic spectrum) and in the ultraviolet. It brightened and diminished at very nearly the same times in both data sets, said MacGregor. “The millimeter and ultraviolet light are very tightly correlated.”

    That’s intriguing, the team suggests, because ultraviolet measurements are somewhat of a holy grail when it comes to stellar flares: Getting a handle on this high-energy emission is critical to understanding whether flare activity might be stripping a planet of its atmosphere or, perhaps, even kick-starting life. But it’s downright difficult to measure ultraviolet light on Earth since our planet’s atmosphere blocks most of its wavelengths, said Katherine Garcia-Sage, a space physicist at NASA Goddard Space Flight Center in Greenbelt, Md., not involved in the research. “We can’t detect them from the ground.” (The Hubble Space Telescope, in orbit roughly 550 kilometers above Earth, is one of the only telescope facilities that can detect ultraviolet light.)

    But millimeter-wavelength emission can be readily detected from Earth’s surface using radio telescopes, said MacGregor. “If the millimeter really is tracing the ultraviolet, we might be able to use these millimeter observations to infer what the ultraviolet light is doing during these events.”

    These results were published last month in The Astrophysical Journal Letters.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

    U Colorado Campus

    As the flagship university of the state of Colorado University of Colorado Boulder (US), founded in 1876, five months before Colorado became a state. It is a dynamic community of scholars and learners situated on one of the most spectacular college campuses in the country, and is classified as an R1 University, meaning that it engages in a very high level of research activity. As one of 34 U.S. public institutions belonging to the prestigious Association of American Universities (US), a selective group of major research universities in North America, – and the only member in the Rocky Mountain region – we have a proud tradition of academic excellence, with five Nobel laureates and more than 50 members of prestigious academic academies.

    CU-Boulder has blossomed in size and quality since we opened our doors in 1877 – attracting superb faculty, staff, and students and building strong programs in the sciences, engineering, business, law, arts, humanities, education, music, and many other disciplines.

    Today, with our sights set on becoming the standard for the great comprehensive public research universities of the new century, we strive to serve the people of Colorado and to engage with the world through excellence in our teaching, research, creative work, and service.

    In 2015, the university comprised nine colleges and schools and offered over 150 academic programs and enrolled almost 17,000 students. Five Nobel Laureates, nine MacArthur Fellows, and 20 astronauts have been affiliated with CU Boulder as students; researchers; or faculty members in its history. In 2010, the university received nearly $454 million in sponsored research to fund programs like the Laboratory for Atmospheric and Space Physics and JILA. CU Boulder has been called a Public Ivy, a group of publicly funded universities considered as providing a quality of education comparable to those of the Ivy League.

    The Colorado Buffaloes compete in 17 varsity sports and are members of the NCAA Division I Pac-12 Conference. The Buffaloes have won 28 national championships: 20 in skiing, seven total in men’s and women’s cross country, and one in football. The university has produced a total of ten Olympic medalists. Approximately 900 students participate in 34 intercollegiate club sports annually as well.

    On March 14, 1876, the Colorado territorial legislature passed an amendment to the state constitution that provided money for the establishment of the University of Colorado in Boulder, the Colorado School of Mines(US) in Golden, and the Colorado State University (US) – College of Agricultural Sciences in Fort Collins.

    Two cities competed for the site of the University of Colorado: Boulder and Cañon City. The consolation prize for the losing city was to be home of the new Colorado State Prison. Cañon City was at a disadvantage as it was already the home of the Colorado Territorial Prison. (There are now six prisons in the Cañon City area.)

    The cornerstone of the building that became Old Main was laid on September 20, 1875. The doors of the university opened on September 5, 1877. At the time, there were few high schools in the state that could adequately prepare students for university work, so in addition to the University, a preparatory school was formed on campus. In the fall of 1877, the student body consisted of 15 students in the college proper and 50 students in the preparatory school. There were 38 men and 27 women, and their ages ranged from 12–23 years.

    During World War II, Colorado was one of 131 colleges and universities nationally that took part in the V-12 Navy College Training Program which offered students a path to a navy commission.

    CU hired its first female professor, Mary Rippon, in 1878. It hired its first African-American professor, Charles H. Nilon, in 1956, and its first African-American librarian, Mildred Nilon, in 1962. Its first African American female graduate, Lucile Berkeley Buchanan, received her degree in 1918.

    Research institutes

    CU Boulder’s research mission is supported by eleven research institutes within the university. Each research institute supports faculty from multiple academic departments, allowing institutes to conduct truly multidisciplinary research.

    The Institute for Behavioral Genetics (IBG) is a research institute within the Graduate School dedicated to conducting and facilitating research on the genetic and environmental bases of individual differences in behavior. After its founding in 1967 IBG led the resurging interest in genetic influences on behavior. IBG was the first post-World War II research institute dedicated to research in behavioral genetics. IBG remains one of the top research facilities for research in behavioral genetics, including human behavioral genetics, psychiatric genetics, quantitative genetics, statistical genetics, and animal behavioral genetics.

    The Institute of Cognitive Science (ICS) at CU Boulder promotes interdisciplinary research and training in cognitive science. ICS is highly interdisciplinary; its research focuses on education, language processing, emotion, and higher level cognition using experimental methods. It is home to a state of the art fMRI system used to collect neuroimaging data.

    ATLAS Institute is a center for interdisciplinary research and academic study, where engineering, computer science and robotics are blended with design-oriented topics. Part of CU Boulder’s College of Engineering and Applied Science, the institute offers academic programs at the undergraduate, master’s and doctoral levels, and administers research labs, hacker and makerspaces, and a black box experimental performance studio. At the beginning of the 2018–2019 academic year, approximately 1,200 students were enrolled in ATLAS academic programs and the institute sponsored six research labs.[64]

    In addition to IBG, ICS and ATLAS, the university’s other institutes include Biofrontiers Institute, Cooperative Institute for Research in Environmental Sciences, Institute of Arctic & Alpine Research (INSTAAR), Institute of Behavioral Science (IBS), JILA, Laboratory for Atmospheric & Space Physics (LASP), Renewable & Sustainable Energy Institute (RASEI), and the University of Colorado Museum of Natural History.

     
  • richardmitnick 9:16 am on May 8, 2021 Permalink | Reply
    Tags: "Massive flare seen on the closest star to the solar system- What it means for chances of alien neighbors", , , , , Proxima Centauri,   

    From The Conversation : “Massive flare seen on the closest star to the solar system- What it means for chances of alien neighbors” 

    From The Conversation

    May 3, 2021

    R. O. Parke Loyd
    Post-Doctoral Researcher in Astrophysics
    Arizona State University

    The Sun isn’t the only star to produce stellar flares. On April 21, 2021, a team of astronomers published new research [The Astrophysical Journal Letters] describing the brightest flare ever measured from Proxima Centauri in ultraviolet light.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    To learn about this extraordinary event – and what it might mean for any life on the planets orbiting Earth’s closest neighboring star – The Conversation spoke with Parke Loyd, an astrophysicist at Arizona State University and co-author of the paper. Excerpts from our conversation are below and have been edited for length and clarity.

    Why were you looking at Proxima Centauri?

    Proxima Centauri is the closest star to this solar system. A couple of years ago, a team discovered that there is a planet – called Proxima b – orbiting the star. It’s just a little bit bigger than Earth, it’s probably rocky and it is in what is called the habitable zone, or the Goldilocks zone. This means that Proxima b is about the right distance from the star so that it could have liquid water on its surface.

    But this star system differs from the Sun in a pretty key way. Proxima Centauri is a small star called a red dwarf – it’s around 15% of the radius of our Sun, and it’s substantially cooler. So Proxima b, in order for it to be in that Goldilocks zone, actually is a lot closer to Proxima Centauri than Earth is to the Sun.

    You might think that a smaller star would be a tamer star, but that’s actually not the case at all – red dwarfs produce stellar flares a lot more frequently than the Sun does. So Proxima b, the closest planet in another solar system with a chance for having life, is subject to space weather that is a lot more violent than the space weather in Earth’s solar system.

    What did you find?

    In 2018, my colleague Meredith MacGregor discovered flashes of light coming from Proxima Centauri that looked very different from solar flares. She was using a telescope that detects light at millimeter wavelengths to monitor Proxima Centauri and saw a big of flash of light in this wavelength. Astronomers had never seen a stellar flare in millimeter wavelengths of light.

    My colleagues and I wanted to learn more about these unusual brightenings in the millimeter light coming from the star and see whether they were actually flares or some other phenomenon. We used nine telescopes on Earth, as well as a satellite observatory, to get the longest set of observations – about two days’ worth – of Proxima Centauri with the most wavelength coverage that had ever been obtained.

    Immediately we discovered a really strong flare. The ultraviolet light of the star increased by over 10,000 times in just a fraction of a second. If humans could see ultraviolet light, it would be like being blinded by the flash of a camera. Proxima Centauri got bright really fast. This increase lasted for only a couple of seconds, and then there was a gradual decline.

    This discovery confirmed that indeed, these weird millimeter emissions are flares.

    What does that mean for chances of life on the planet?

    Astronomers are actively exploring this question at the moment because it can kind of go in either direction. When you hear ultraviolet radiation, you’re probably thinking about the fact that people wear sunscreen to try to protect ourselves from ultraviolet radiation here on Earth. Ultraviolet radiation can damage proteins and DNA in human cells, and this results in sunburns and can cause cancer. That would potentially be true for life on another planet as well.

    On the flip side, messing with the chemistry of biological molecules can have its advantages – it could help spark life on another planet. Even though it might be a more challenging environment for life to sustain itself, it might be a better environment for life to be generated to begin with.

    But the thing that astronomers and astrobiologists are most concerned about is that every time one of these huge flares occurs, it basically erodes away a bit of the atmosphere of any planets orbiting that star – including this potentially Earth-like planet. And if you don’t have an atmosphere left on your planet, then you definitely have a pretty hostile environment to life – there would be huge amounts of radiation, massive temperature fluctuations and little or no air to breathe. It’s not that life would be impossible, but having the surface of a planet basically directly exposed to space would be an environment totally different than anything on Earth.

    Is there any atmosphere left on Proxima b?

    That’s anybody’s guess at the moment. The fact that these flares are happening doesn’t bode well for that atmosphere being intact – especially if they’re associated with explosions of plasma like what happens on the Sun. But that’s why we’re doing this work. We hope the folks who build models of planetary atmospheres can take what our team has learned about these flares and try to figure out the odds for an atmosphere being sustained on this planet.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 1:03 pm on April 21, 2021 Permalink | Reply
    Tags: "Humongous flare from sun’s nearest neighbor breaks records", , , , , , Proxima Centauri, ,   

    From University of Colorado Boulder: “Humongous flare from sun’s nearest neighbor breaks records” 

    U Colorado

    From University of Colorado Boulder

    April 21, 2021
    Daniel Strain

    1
    Artist’s conception of a violent flare erupting from the star Proxima Centauri. (Credit: National Radio Astronomy Observatory (US)/S. Dagnello)

    Scientists have spotted the largest flare ever recorded from the sun’s nearest neighbor, the star Proxima Centauri.

    The research, which appears today in The Astrophysical Journal Letters, was led by CU Boulder and could help to shape the hunt for life beyond Earth’s solar system.

    CU Boulder astrophysicist Meredith MacGregor explained that Proxima Centauri is a small but mighty star. It sits just four light-years or more than 20 trillion miles from our own sun and hosts at least two planets, one of which may look something like Earth. It’s also a “red dwarf,” the name for a class of stars that are unusually petite and dim.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    Proxima Centauri has roughly one-eighth the mass of our own sun. But don’t let that fool you.

    In their new study, MacGregor and her colleagues observed Proxima Centauri for 40 hours using nine telescopes on the ground and in space. In the process, they got a surprise: Proxima Centauri ejected a flare, or a burst of radiation that begins near the surface of a star, that ranks as one of the most violent seen anywhere in the galaxy.

    “The star went from normal to 14,000 times brighter when seen in ultraviolet wavelengths over the span of a few seconds,” said MacGregor, an assistant professor at the Center for Astrophysics and Space Astronomy (CASA) and Department of Astrophysical and Planetary Sciences (APS) at CU Boulder.

    The team’s findings hint at new physics that could change the way scientists think about stellar flares. They also don’t bode well for any squishy organism brave enough to live near the volatile star.

    “If there was life on the planet nearest to Proxima Centauri, it would have to look very different than anything on Earth,” MacGregor said. “A human being on this planet would have a bad time.”

    Active stars

    The star has long been a target for scientists hoping to find life beyond Earth’s solar system. Proxima Centauri is nearby, for a start. It also hosts one planet, designated Proxima Centauri b, that resides in what researchers call the “habitable zone”—a region around a star that has the right range of temperatures for harboring liquid water on the surface of a planet.

    But there’s a twist, MacGregor said: Red dwarves, which rank as the most common stars in the galaxy, are also unusually lively.

    “A lot of the exoplanets that we’ve found so far are around these types of stars,” she said. “But the catch is that they’re way more active than our sun. They flare much more frequently and intensely.”

    To see just how much Proxima Centauri flares, she and her colleagues pulled off what approaches a coup in the field of astrophysics: They pointed nine different instruments at the star for 40 hours over the course of several months in 2019. Those eyes included the Hubble Space Telescope, the Atacama Large Millimeter Array (ALMA) and NASA’s Transiting Exoplanet Survey Satellite (TESS). Five of them recorded the massive flare from Proxima Centauri, capturing the event as it produced a wide spectrum of radiation.

    “It’s the first time we’ve ever had this kind of multi-wavelength coverage of a stellar flare,” MacGregor. “Usually, you’re lucky if you can get two instruments.”

    Crispy planet

    The technique delivered one of the most in-depth anatomies of a flare from any star in the galaxy.

    The event in question was observed on May 1, 2019 and lasted just 7 seconds. While it didn’t produce a lot of visible light, it generated a huge surge in both ultraviolet and radio, or “millimeter,” radiation.

    “In the past, we didn’t know that stars could flare in the millimeter range, so this is the first time we have gone looking for millimeter flares,” MacGregor said.

    Those millimeter signals, MacGregor added, could help researchers gather more information about how stars generate flares. Currently, scientists suspect that these bursts of energy occur when magnetic fields near a star’s surface twist and snap with explosive consequences.

    In all, the observed flare was roughly 100 times more powerful than any similar flare seen from Earth’s sun. Over time, such energy can strip away a planet’s atmosphere and even expose life forms to deadly radiation.

    That type of flare may not be a rare occurrence on Proxima Centauri. In addition to the big boom in May 2019, the researchers recorded many other flares during the 40 hours they spent watching the star.

    “Proxima Centauri’s planets are getting hit by something like this not once in a century, but at least once a day if not several times a day,” MacGregor said.

    The findings suggest that there may be more surprises in store from the sun’s closest companion.

    “There will probably be even more weird types of flares that demonstrate different types of physics that we haven’t thought about before,” MacGregor said.

    Other coauthors on the new study include Steven Cranmer, associate professor in APS and the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder; Adam Kowalski, assistant professor in APS and LASP at CU Boulder, also of the National Solar Observatory; Allison Youngblood, research scientist at LASP; and Anna Estes, undergraduate research assistant in APS.

    The Carnegie Institution for Science (US), Arizona State University (US), NASA Goddard Spaceflight Center (US), University of Maryland (US), University of North Carolina at Chapel Hill (US), University of Sydney (AU), CSIRO Astronomy and Space Science (AU), NASA Space Telescope Science Institute (US), Johns Hopkins University (US), the Harvard Smithsonian Center for Astrophysics (US) and the University of British Columbia (CA) also contributed to this research.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Colorado Campus

    As the flagship university of the state of Colorado University of Colorado Boulder(US), founded in 1876, five months before Colorado became a state. It is a dynamic community of scholars and learners situated on one of the most spectacular college campuses in the country, and is classified as an R1 University, meaning that it engages in a very high level of research activity. As one of 34 U.S. public institutions belonging to the prestigious Association of American Universities (AAU), a selective group of major research universities in North America, – and the only member in the Rocky Mountain region – we have a proud tradition of academic excellence, with five Nobel laureates and more than 50 members of prestigious academic academies.

    CU-Boulder has blossomed in size and quality since we opened our doors in 1877 – attracting superb faculty, staff, and students and building strong programs in the sciences, engineering, business, law, arts, humanities, education, music, and many other disciplines.

    Today, with our sights set on becoming the standard for the great comprehensive public research universities of the new century, we strive to serve the people of Colorado and to engage with the world through excellence in our teaching, research, creative work, and service.

    In 2015, the university comprised nine colleges and schools and offered over 150 academic programs and enrolled almost 17,000 students. Five Nobel Laureates, nine MacArthur Fellows, and 20 astronauts have been affiliated with CU Boulder as students; researchers; or faculty members in its history. In 2010, the university received nearly $454 million in sponsored research to fund programs like the Laboratory for Atmospheric and Space Physics and JILA. CU Boulder has been called a Public Ivy, a group of publicly funded universities considered as providing a quality of education comparable to those of the Ivy League.

    The Colorado Buffaloes compete in 17 varsity sports and are members of the NCAA Division I Pac-12 Conference. The Buffaloes have won 28 national championships: 20 in skiing, seven total in men’s and women’s cross country, and one in football. The university has produced a total of ten Olympic medalists. Approximately 900 students participate in 34 intercollegiate club sports annually as well.

    On March 14, 1876, the Colorado territorial legislature passed an amendment to the state constitution that provided money for the establishment of the University of Colorado in Boulder, the Colorado School of Mines(US) in Golden, and the Colorado State University (US) – College of Agricultural Sciences in Fort Collins.

    Two cities competed for the site of the University of Colorado: Boulder and Cañon City. The consolation prize for the losing city was to be home of the new Colorado State Prison. Cañon City was at a disadvantage as it was already the home of the Colorado Territorial Prison. (There are now six prisons in the Cañon City area.)

    The cornerstone of the building that became Old Main was laid on September 20, 1875. The doors of the university opened on September 5, 1877. At the time, there were few high schools in the state that could adequately prepare students for university work, so in addition to the University, a preparatory school was formed on campus. In the fall of 1877, the student body consisted of 15 students in the college proper and 50 students in the preparatory school. There were 38 men and 27 women, and their ages ranged from 12–23 years.

    During World War II, Colorado was one of 131 colleges and universities nationally that took part in the V-12 Navy College Training Program which offered students a path to a navy commission.

    CU hired its first female professor, Mary Rippon, in 1878. It hired its first African-American professor, Charles H. Nilon, in 1956, and its first African-American librarian, Mildred Nilon, in 1962. Its first African American female graduate, Lucile Berkeley Buchanan, received her degree in 1918.

    Research institutes

    CU Boulder’s research mission is supported by eleven research institutes within the university. Each research institute supports faculty from multiple academic departments, allowing institutes to conduct truly multidisciplinary research.

    The Institute for Behavioral Genetics (IBG) is a research institute within the Graduate School dedicated to conducting and facilitating research on the genetic and environmental bases of individual differences in behavior. After its founding in 1967 IBG led the resurging interest in genetic influences on behavior. IBG was the first post-World War II research institute dedicated to research in behavioral genetics. IBG remains one of the top research facilities for research in behavioral genetics, including human behavioral genetics, psychiatric genetics, quantitative genetics, statistical genetics, and animal behavioral genetics.

    The Institute of Cognitive Science (ICS) at CU Boulder promotes interdisciplinary research and training in cognitive science. ICS is highly interdisciplinary; its research focuses on education, language processing, emotion, and higher level cognition using experimental methods. It is home to a state of the art fMRI system used to collect neuroimaging data.

    ATLAS Institute is a center for interdisciplinary research and academic study, where engineering, computer science and robotics are blended with design-oriented topics. Part of CU Boulder’s College of Engineering and Applied Science, the institute offers academic programs at the undergraduate, master’s and doctoral levels, and administers research labs, hacker and makerspaces, and a black box experimental performance studio. At the beginning of the 2018–2019 academic year, approximately 1,200 students were enrolled in ATLAS academic programs and the institute sponsored six research labs.[64]

    In addition to IBG, ICS and ATLAS, the university’s other institutes include Biofrontiers Institute, Cooperative Institute for Research in Environmental Sciences, Institute of Arctic & Alpine Research (INSTAAR), Institute of Behavioral Science (IBS), JILA, Laboratory for Atmospheric & Space Physics (LASP), Renewable & Sustainable Energy Institute (RASEI), and the University of Colorado Museum of Natural History.

     
  • richardmitnick 11:51 am on December 31, 2020 Permalink | Reply
    Tags: "Was That a Dropped Call From ET?", "Wow!" signal from Ohio State Big Ear Radio Telescope Aug. 15 1977., A spooky radio signal showed up after a radio telescope was aimed at the next star over from our sun., , , Green Bank Observatory radio telescope Green Bank West Virginia, Parkes Observatory in Australia, Proxima Centauri,   

    From The New York Times: “Was That a Dropped Call From ET?” 

    From The New York Times

    Dec. 31, 2020
    Dennis Overbye

    A spooky radio signal showed up after a radio telescope was aimed at the next star over from our sun.

    1
    Proxima Centauri, the closest known star to our own sun, is found in the constellation Centaurus and is not visible to the naked eye. The mysterious signal came from its direction.Credit: NASA/ESA Hubble.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    Nobody believes it was ET phoning, but radio astronomers admit they don’t have an explanation yet for a beam of radio waves that apparently came from the direction of the star Proxima Centauri.

    “It’s some sort of technological signal. The question is whether it’s Earth technology or technology from somewhere out yonder,” said Sofia Sheikh, a graduate student at Pennsylvania State University leading a team studying the signal and trying to decipher its origin. She is part of Breakthrough Listen, a $100 million effort funded by Yuri Milner, a Russian billionaire investor, to find alien radio waves.

    Breakthrough Listen Project

    1

    UC Observatories Lick Autmated Planet Finder, fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA




    GBO radio telescope, Green Bank, West Virginia, USA


    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia


    SKA SARAO Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA.


    Newly added

    CfA/VERITAS, a major ground-based gamma-ray observatory with an array of four Čerenkov Telescopes for gamma-ray astronomy in the GeV – TeV energy range. Located at Fred Lawrence Whipple Observatory,Mount Hopkins, Arizona, US in AZ, USA, Altitude 2,606 m (8,550 ft)

    The project has now stumbled on its most intriguing pay dirt yet.

    Proxima Centauri is an inviting prospect for “out yonder.”

    It is the closest known star to the sun, only 4.24 light-years from Earth, part of a triple-star system known as Alpha Centauri. Proxima has at least two planets, one of which is a rocky world only slightly more massive than Earth that occupies the star’s so-called habitable zone, where temperatures should be conducive to water, the stuff of life, on its surface.

    The radio signal itself, detected in spring 2019 and reported on earlier in The Guardian, is in many ways the stuff of dreams for alien hunters. It was a narrow-band signal with a frequency of 982.02 MHz as recorded at the Parkes Observatory in Australia [above]. Nature, whether an exploding star or a geomagnetic storm, tends to broadcast on a wide range of frequencies.

    “The signal appears to only show up in our data when we’re looking in the direction of Proxima Centauri, which is exciting,” Ms. Sheikh said. “That’s a threshold that’s never been passed by any signal that we’ve seen previously, but there are a lot of caveats.”

    Practitioners of the hopeful field of the search for extraterrestrial intelligence, also known as SETI, say they have seen it all before.

    “We’ve seen these types of signal before, and it’s always turned out to be R.F.I., radio frequency interference,” Dan Werthimer, chief technologist at the Berkeley SETI Research Center, who is not part of the Proxima Centauri study, wrote in an email.

    That thought was echoed by his Berkeley colleague Andrew Siemion, who is the principal investigator for Breakthrough Listen. “Our experiment exists in a sea of interfering signals,” he said.

    “My instinct in the end is that it will be anthropogenic in origin,” he added. “But so far we can’t yet fully explain it.”

    So there’s nothing to see here, folks. Until there is. Notwithstanding claims of biosignature gases on Venus and tales of U.F.O. sightings collected by the Pentagon, the discovery of life, let alone intelligence, out there would be a psychological thunderclap of cosmic and historic proportions.

    False alarms have been part of SETI since the very beginning, when Frank Drake, then at Cornell and now retired from the University of California, Santa Cruz, pointed a radio telescope in Green Bank, W.Va., in 1960 at a pair of stars, hoping to hear aliens’ radio waves.

    Frank Drake with his Drake Equation. Credit Frank Drake.

    He detected what seemed to be a signal. Could it be this easy to discover we are not alone?

    It turned out to be a secret military experiment.

    Sixty years later we are still officially alone and SETI as an enterprise has been through the wars economically and politically even as technology has enhanced humanity’s ability to comb the nearly infinite haystack of planets, stars and “magical frequencies” on which They might be broadcasting.

    Breakthrough Listen was announced with much fanfare by Mr. Milner and Stephen Hawking in 2015, sparking what Dr. Siemion called a renaissance.

    “This is the best time to be doing SETI,” he said.

    The recent excitement began on April 29, 2019, when Breakthrough Listen scientists turned the Parkes radio telescope [above] on Proxima Centauri, to monitor the star for violent flares. It is a small star known as a red dwarf. These stars are prone to such outbursts, which could strip the atmosphere from a planet and render it unlivable.

    In all they recorded 26 hours of data. The Parkes radio telescope, however, was equipped with a new receiver capable of resolving narrow-band signals of the type SETI researchers seek. So in fall 2020, the team decided to search the data for such signals, a job that fell to Shane Smith, an undergraduate at Hillsdale College in Michigan and an intern with Breakthrough.

    The signal that surprised the team appeared five times on April 29 during a series of 30-minute windows in which the telescope was pointed in the direction of Proxima Centauri. It has not appeared since. It was a pure unmodulated tone, meaning it appeared to carry no message except the fact of its own existence.

    The signal also showed a tendency to drift slightly in frequency during the 30-minute intervals, a sign that whatever the signal came from is not on the surface of Earth, but often correlates with a rotating or orbiting object.

    But the drift does not match the motions of any known planets in Proxima Centauri. And in fact the signal, if it is real, might be coming from someplace beyond the Alpha Centauri system. Who knows?

    The subsequent nonappearance of the signal has prompted comparisons to a famous detection known as the “Wow! Signal” that appeared on a printout from the Big Ear radio telescope, operated by Ohio State University in 1977.

    “Wow!” signal from Ohio State Big Ear Radio Telescope Aug. 15, 1977.

    Ohio State Big Ear Radio Telescope, Construction of the Big Ear began in 1956 and was completed in 1961, and it was finally turned on for the first time in 1963, disassembled in 1998 having operated for over 30 years.

    Jerry Ehman, a now retired astronomer, wrote “Wow!” on the side of the printout when he saw it after that fact. The signal never appeared again, nor was it satisfactorily explained, and some people still wonder if it was a missed call from Out There.

    Of the Proxima signal, Dr. Siemion said, “There have been some exclamations but ‘wow’ hasn’t been one of them.”

    Asked what they were, he laughed.

    “Initially there were perplexed reactions from folks, but it settled down quickly,” he said.

    Over a period of 24 to 48 hours at the end of this October, he said, the mood shifted from inquisitive and curious to “very serious scientific detective work.”

    Ms. Sheikh, who expects to get her doctorate this coming summer, is leading the detective work. She got her bachelor’s degree at the University of California, Berkeley, intending to go into particle physics, but found herself drifting into astronomy instead. She first heard about the Breakthrough Listen project and SETI on Reddit while she was looking for a new undergraduate research project.

    “I would say we were extremely skeptical at first, and I remain skeptical,” she said about the putative signal. But she added that it was “the most interesting signal to come through the Breakthrough Listen program.”

    The team hopes to publish its results early in 2021.

    The Parkes telescope — which once relayed communications to the Apollo astronauts — is notorious for false alarms, Dr. Werthimer says. In one recent example, he said, astronomers thought they had discovered a new astrophysical phenomenon.

    “It was very exciting until somebody noticed the signals only appeared at the lunch hour,” he said. They were coming from a microwave oven.

    Over the years SETI astronomers have prided themselves on their ability to chase down the source of suspicious signals and eliminate them before word leaked out to the public.

    This time their work was reported by The Guardian. “The public wants to know, we get that,” Dr. Siemion said. But, as he and Ms. Sheikh emphasize, they aren’t nearly done yet.

    “Frankly, there’s still a lot of analysis that we have to do to be confident that this thing is not interference,” Ms. Sheikh said.

    Part of the problem, she explained, is that the original observations were not done according to the standard SETI protocol. Normally, a radio telescope would point at a star or other target for five minutes and then “nod” slightly away from it for five minutes to see if the signal persisted.

    In the Proxima observations, however, the telescope pointed for 30 minutes and then moved far across the sky (30 degrees or so) for five minutes to a quasar the astronomers were using to calibrate the brightness of the star’s flares. Such a large swing might have taken the telescope away from whatever the source of the radio interference was.

    If all else fails, Ms. Sheikh said, they will try to reproduce the results by replicating the exact movements of the Parkes telescope again on April 29, 2021.

    “Because,” she said, “if it’s actually coming from Proxima, then maybe they would like send a hello once a year or something like that.” She went on, “But it’s more likely that there’s some sort of yearly event that happens at the visitor center, or something like that, that causes an environmental effect that doesn’t happen the rest of the year.”

    The Proxima signal could be destined to pass into legend like the Ohio State Wow! Signal, but in SETI, there is always another day, another star.

    It’s been fun, Ms. Sheikh said, even if the Proxima signal ends up being interference.

    “This is extremely exciting, no matter what comes out of it.”

    See the full article here .

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    Please help promote STEM in your local schools.

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  • richardmitnick 9:28 am on December 23, 2020 Permalink | Reply
    Tags: "Space weather in Proxima’s vicinity dims hopes of habitable worlds", , , , , , , Proxima Centauri,   

    From University of Sydney (AU) via EarthSky: “Space weather in Proxima’s vicinity dims hopes of habitable worlds” 

    U Sidney bloc

    From University of Sydney (AU)

    via

    1

    EarthSky

    December 23, 2020
    Paul Scott Anderson

    Astronomers used radio waves to study conditions in the vicinity of Proxima Centauri, the nearest star to our sun. The results suggest Proxima’s 2 known planets are likely bathed in intense radiation from this star, casting doubt on the planets’ potential for life.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    1
    Artist’s concept of huge flares on Proxima Centauri, which unleash ionizing radiation. This radiation could be dangerous for any possible life on planets orbiting close to the star. Image via NASA/ ESA/ G. Bacon (STScI)/ Phys.org.

    This month, even as some astronomers are talking about a possible mystery radio signal from Proxima Centauri – a signal of interest to astronomers who search for intelligent life beyond Earth – other astronomers are talking about space weather in the vicinity of this star, which is the nearest star to our sun. Space weather in Proxima’s vicinity, they are saying, might make life on its planets difficult or even impossible.

    What is space weather?

    When we hear about weather, we might think of Earth – sun, clouds, rain, wind and so on – or we might think about conditions on other planets or moons that have atmospheres. Space weather isn’t about that. It’s a sort of “weather” that originates in stars, including our own sun, and that permeates the space near a star. Space weather consists of ionizing radiation released during flares on the sun, or other stars.

    Space weather. Credit: NASA.

    The radiation can be deadly for any life forms that may exist on distant planets. That’s especially true, astronomers say, for red dwarf stars, which have more frequent flares than our sun. Red dwarf stars can be very volatile. Proxima Centauri is a red dwarf star.

    Astronomers at the University of Sydney in Australia announced the new study on December 10, 2020. These researchers used radio waves to detect and probe the space weather in Proxima’s vicinity. Our sun’s nearest neighbor at only 4.2 light-years away, Proxima is known to have at least two planets orbiting it. One, Proxima Centauri b, is almost the same mass as Earth and the other, Proxima Centauri c, is about seven times more massive. Proxima Centauri b also orbits within its stars’ habitable zone, where temperatures might allow liquid water to exist on planet’s surface. Sounds promising, right? But the new findings about flares on stars like Proxima suggests a grim prospect for life on the planets in this system.

    The researchers published their peer-reviewed findings in The Astronomical Journal on December 9.

    These astronomers worked with CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) telescope in Western Australia and the Zadko Telescope at the University of Western Australia, as well as other instruments. Tara Murphy of the University of Sydney helped lead the study.

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    3
    The Zadko telescope is used by staff at the University of Western Australia and scientists in France. Credit: ABC Radio Perth: Emma Wynne.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
  • richardmitnick 4:00 pm on December 9, 2020 Permalink | Reply
    Tags: "Space weather discovery puts 'habitable planets' at risk", , , , , , Proxima Centauri, ,   

    From University of Sydney (AU) via phys.org: “Space weather discovery puts ‘habitable planets’ at risk” 

    U Sidney bloc

    From University of Sydney (AU)

    via


    phys.org

    December 9, 2020

    1
    Artist’s impression of flare from our neighbouring star Proxima Centauri ejecting material onto a nearby planet. Credit: Mark Myers/OzGrav.

    A discovery that links stellar flares with radio-burst signatures will make it easier for astronomers to detect space weather around nearby stars outside the Solar System. Unfortunately, the first weather reports from our nearest neighbour, Proxima Centauri, are not promising for finding life as we know it.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    “Astronomers have recently found [Science Advances] there are two ‘Earth-like’ rocky planets around Proxima Centauri, one within the ‘habitable zone’ [Nature] where any water could be in liquid form,” said Andrew Zic from the University of Sydney.

    Proxima Centauri is just 4.2 light years from Earth.

    “But given Proxima Centauri is a cool, small red-dwarf star, it means this habitable zone is very close to the star; much closer in than Mercury is to our Sun,” he said.

    “What our research shows is that this makes the planets very vulnerable to dangerous ionising radiation that could effectively sterilise the planets.”

    Led by Mr Zic, astronomers have for the first time shown a definitive link between optical flares and radio bursts on a star that is not the Sun. The finding, published today in The Astrophysical Journal, is an important step to using radio signals from distant stars to effectively produce space weather reports.

    “Our own Sun regularly emits hot clouds of ionised particles during what we call ‘coronal mass ejections’. But given the Sun is much hotter than Proxima Centauri and other red-dwarf stars, our ‘habitable zone’ is far from the Sun’s surface, meaning the Earth is a relatively long way from these events,” Mr Zic said.

    “Further, the Earth has a very powerful planetary magnetic field that shields us from these intense blasts of solar plasma.”

    The research was done in collaboration with CSIRO, the University of Western Australia, University of Wisconsin-Milwaukee, University of Colorado and Curtin University. There were contributions from the ARC Centre for Gravitational Waves and University of California Berkeley.

    The study formed part of Mr Zic’s doctoral studies at the Sydney Institute for Astronomy under the supervision of Professor Tara Murphy, deputy head of the School of Physics at the University of Sydney. Mr Zic has now taken a joint position at Macquarie University and CSIRO.

    He said: “M-dwarf radio bursts might happen for different reasons than on the Sun, where they are usually associated with coronal mass ejections. But it’s highly likely that there are similar events associated with the stellar flares and radio bursts we have seen in this study.”

    Coronal mass ejections are hugely energetic expulsions of ionised plasma and radiation leaving the stellar atmosphere.

    “This is probably bad news on the space weather front. It seems likely that the galaxy’s most common stars—red dwarfs—won’t be great places to find life as we know it,” Mr Zic said.

    In the past decade, there has been a renaissance in the discovery of planets orbiting stars outside our Solar System. There are now more than 4000 known exoplanets.

    This has boosted hopes of finding ‘Earth-like’ conditions on exoplanets. Recent research says that about half the Sun-like stars in the Milky Way could be home to such planets. However, Sun-like stars only make up 7 percent of the galaxy’s stellar objects. By contrast, M-type red dwarfs like Proxima Centauri make up about 70 percent of stars in the Milky Way.

    The findings strongly suggest planets around these stars are likely to be showered with stellar flares and plasma ejections.

    Methodology

    The Proxima Centauri observations were taken with the CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) telescope in Western Australia, the Zadko Telescope at the University of Western Australia and a suite of other instruments.

    University of Western Australia scientist Dr. Bruce Gendre, from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), said the research helps understand the dramatic effects of space weather on solar systems beyond our own.

    “Understanding space weather is critical for understanding how our own planet biosphere evolved—but also for what the future is,” Dr. Gendre said.

    Professor Murphy said: “This is an exciting result from ASKAP. The incredible data quality allowed us to view the stellar flare from Proxima Centauri over its full evolution in amazing detail.

    “Most importantly, we can see polarised light, which is a signature of these events. It’s a bit like looking at the star with sunglasses on. Once ASKAP is operating in full survey mode we should be able to observe many more events on nearby stars.”

    This will give us much greater insights to the space weather around nearby stars.

    Other facilities, including NASA’s planet-hunting Transiting Exoplanet Survey Satellite and the Zadko Telescope observed simultaneously with ASKAP providing the crucial link between the radio bursts and powerful optical flares observed.

    Mr Zic said: “The probability that the observed solar flare and received radio signal from our neighbour were not connected is much less than one chance in 128,000.”

    The research shows that planets around Proxima Centauri may suffer strong atmospheric erosion, leaving them exposed to very intense X-rays and ultraviolet radiation.

    But could there be magnetic fields protecting these planets?

    Mr Zic said: “This remains an open question. How many exoplanets have magnetic fields like ours?”

    So far there have been no observations of magnetic fields around exoplanets and finding these could prove tricky. Mr Zic said one potential way to identify distant magnetic fields would be to look for aurorae, like those around Earth and also witnessed on Jupiter.

    “But even if there were magnetic fields, given the stellar proximity of habitable zone planets around M-dwarf stars, this might not be enough to protect them,” Mr Zic said.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
  • richardmitnick 10:34 am on November 8, 2017 Permalink | Reply
    Tags: , , , , , Proxima Centauri,   

    From Red Dots: “Full HARPS 2017 dataset now available” 

    Red Dots

    7th November 2017
    Guillem Anglada-Escude

    1
    We have been a bit busy organizing the data, but the final HARPS dataset from Red Dots is now available for downloads at

    https://spasrv09.ph.qmul.ac.uk/owncloud/index.php/s/6CChGuyxNjPQRnP

    If you want make use of the data for scientific publications, remember that this is still preliminary, and that we welcome contributions and open discussions on this dataset. We mentioned the possibility of a second strong signal in Proxima’s RVs. Instead of forcing our conclusions into you, we let you take a look at all the observations and try to draw your initial conclusions (if you are new, we suggest using the systemic tool) For those with technical expertise in high resolution spectroscopy and science formats, you can access the ESO reduced files in the Proxima/Spectra folder, and the corresponding up-to-date radial velocities in Proxima/timeseries/.

    2
    Periodogram search on the ‘Red Dots 2017’ data set only. As in last year, the signal at ~11 days is significant in the new set, adding further robustness to the detection of Proxima b. This also implies we are likely to reach similar sensitivities on the other two stars (Barnard’s and Ross 154). Exciting. Combination with previous data might reveal additional signals, but these analyses will take more time and thinking. Image credits : Guillem Anglada/Red Dots

    A very quick analyses of the 2017 only data, shows that the signal of Proxima b is again detected with the new data set only! This was not the case for a while (data from first weeks was not as good as last year), but it looks like that in the end Proxima b’s signal remains in healthy confirmed state.

    3
    The spectrum taken on Sep 24th and a few other nights was not usable due to contamination by Sun-light. This typically happens due to twilight observation, moon proximity and/or the presence of high clouds scattering light. Red is the spectra registered on Sep 24th, and black is data registered in a good night with dark conditions. Image credits : Guillem Anglada-Escude/Red Dots

    It is worth mentioning that we dropped three spectra because they were badly contaminated with solar-like stray-light. That happens because they were taken a bit too early after the sunset, because the moon was near the star on the sky, presence of high clouds scattering sun & moonlight, or a combination of the three. These spectra are in Proxima/Spectra/contaminated/ in case anyone has a use for them.

    The photometric datasets are almost ready, but we need to clean them up and organize a little. Data is coming from more than a dozen observatories and the formats are not fully consistent with each other. Lot’s of spreadsheet work to do!

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Red dots is a project to attempt detection of the nearest terrestrial planets to the Sun. Terrestrial planets in temperate orbits around nearby red dwarf stars can be more easily detected using Doppler spectroscopy, hence the name of the project.

    ESO 3.6m telescope & HARPS at LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO/HARPS at La Silla

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

     
  • richardmitnick 11:43 am on September 14, 2017 Permalink | Reply
    Tags: , , , , , , Proxima Centauri   

    From Pale Red Dot: “HARPS data release #3, independent analyzes & more” 

    Pale Red Dot

    Pale Red Dot

    1
    This unusual Picture of the Week showcases the latest data on Proxima Cenaturi gathered by ESO’s exoplanet hunter, the High Accuracy Radial velocity Planet Searcher (HARPS), during the ongoing Red Dots campaign. The top left graph displays the 2016 data that confirmed the existence of Proxima b, showing how the planet is causing its parent star, Proxima Centauri, to move towards and away from Earth over time. The curved line represents the wobbling signal of the star, with the regular pattern of changing radial velocities (RV) repeating every 11.2 days. The top right graph shows new measurements made with HARPS during the Red Dots campaign in 2017. The new data once again supports the presence of Proxima b’s signal (in yellow), but also includes additional patterns visible here as a downward slope in both the 2016 and 2017 campaigns, hinting that there may be more to be discovered. To make a firmer statement on what is causing these patterns, astronomers need to use quantitative mathematical tools. One such mathematical tool is called a periodogram, which searches for repeating signals in the data displayed here as prominent peaks. Several periods seem promising but it is hard to make a quantitative argument favouring one or another. This typically happens on poorly sampled signals and when the variability is caused by stellar activity.

    As featured in the current ESO picture of the Week, Proxima Centauri keeps showing extra variability beyond the wobble caused by Proxima b. The nature of the variability remains unclear so conclusive evidence will require the combination of all available data (HARPS, UVES spectrometers; but also photometric time-series being collected in both professional and Pro-Am observatories). We will be posting the photometric measurements in short.

    The new radial velocity measurements are now available for download on our website. Share your thoughts or analyses in the comments or via social media Twitter @RedDotsSpace or Facebook.

    For example, our colleagues Mario Damasso and Fabio Del Sordo also have been looking at the new Proxima data (based on HARPS data release #2). This is what they have found so far.

    Proxima re-reloaded! Vol. 1

    by Mario Damasso and Fabio Del Sordo

    We have analysed the radial velocities of Proxima including the new dataset, for a total of 248 measurements. We have modeled the stellar “noise” component through a Gaussian process regression, as we did in our previous work (Damasso & Del Sordo, A&A, 599A 126D, 2017), using a quasi-periodic covariance function, which is particularly suitable when a signal with a frequency related to the stellar rotation period is present in the data.

    Here we briefly summarize the results of the first model we have tested, that takes into account the existence of only one planet. Our discussion is based on the results corresponding to the Maximum a Posteriori likelihood (MAP), i.e. we are presenting single values for all the free parameters of our model corresponding to the maximum of the likelihood function we have used as figure of merit.

    First of all, we recover a planetary signal with semi-amplitude K=1.46 m/s, with orbital period P=11.186 days, moving on a nearly circular orbit (see fig 1.): the signal, already evident in the previous dataset, is therefore once again clearly confirmed.

    2
    Fig 1: Folded phase curve for all the radial velocities collected for Proxima. The red curve represents the best-fit planetary signal we have derived for Proxima b.

    These new data also confirm our previous results. The rotation period of Proxima is present in the radial velocity dataset, because we find a signal with rotational period of about 87 days modeled as correlated noise. One parameter of our model can be seen as the average lifetime of the active regions, for which we find a value of 312 days. The correlated stellar noise induced by stellar activity has an estimated amplitude of 1.82 m/s. All these results are consistent with our previous findings.

    We have analysed the residuals of this model, and we do not find evidence for additional, significant frequencies left in the data. We are now running a model which includes two planets. Stay tuned!
    Links

    European Southern Observatory; Picture of the Week, https://www.eso.org/public/images/potw1737a/
    Damasso & Del Sordo, “Proxima Centauri reloaded: Unravelling the stellar noise in radial velocities”, Astronomy & Astrophysics 2017, Vol 26A, http://adsabs.harvard.edu/abs/2017A%26A…599A.126D

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    What is PALE RED DOT?

    It is an outreach project to show to the public how scientists are working to address a major question that could affect us all, namely are there Earth-like planets around the nearest stars?

    Why we call it PALE RED DOT?

    In 1990, Voyager 1, on its trek towards interstellar space, sent back a picture of the Inner Solar System on which the Earth occupied less than a pixel. This image of Earth was called Pale Blue Dot, and inspired the late Carl Sagan’s essay ‘Pale Blue Dot : A vision of the human future in Space’, which in turn has been the source of inspiration for a generation of exoplanet hunters. Given that Proxima Centauri — or just Proxima — is a red dwarf star, such a planet would show reddish tints. Even if successful, we will only obtain information about its orbital period and mass — even less than Voyager 1’s pale blue pixel… at least for now!

    What is special about the project?

    Proxima Centauri is the nearest star to the Sun. The discovery of a planet with some characteristics like Earth in our immediate vicinity would be momentous. After years of data acquisition by many researchers and teams, a signal has been identified which may indicate the presence of an Earth-like planet. The Pale Red Dot project will carry out further detailed observations with the aim to confirm or refute the presence of the planet. By broadcasting the progress and results of the observations through all media channels available e.g. press, website, and social media, the Pale Red Dot project aims to promote Science Technology Engineering and Mathematics (STEM) in the broader society, inform the public and hopefully inspire a new generation of scientists.

    How such a scientific program is organized?

    The planned observation campaign is based on a proposal submitted by the involved scientists to ESO, LCOGT and BOOTES observatories. The proposals, in turn, are based on the analysis of data accumulated and obtained over the years by ourselves or by other researchers abroad. Observatories and other advanced research facilities are mostly supported by public resources, large international consortia and private foundations.

    How the results will be reported?

    As in any professional scientific work, final results need to be reviewed by the community before being announced. After the campaign is finished by April 1st, the really tough process of analyzing the data, drawing conclusions and presenting them in a credible manner will begin. After that, the analysis will be summarized in an article and submitted to a scientific journal. At that point, one or more scientists NOT involved in the project will critically revise the work, suggest modifications and even reject its publication if fundamental flaws are spotted. This last step of peer-review can take any time between a few months to a year or two. Hopefully, the data will prove to be high quality and the observations will have a straightforward interpretation, but that is just a hope. A few key milestones of the peer-review process will also be reported on the website, which might remain active at a lower activity level after the observing campaign has finished.

     
  • richardmitnick 8:38 am on December 24, 2016 Permalink | Reply
    Tags: , , , , , Proxima Centauri   

    From ESO: “Orbit of Proxima Centauri Determined After 100 Years” 

    ESO 50 Large

    European Southern Observatory

    22 December 2016
    Pierre Kervella
    Universidad de Chile, CNRS UMI 3386 & LESIA, Paris Observatory
    Camino El Observatoria 1515, Las Condes
    Santiago, Chile
    Email:
    pkervell@das.uchile.cl

    Frédéric Thévenin
    Observatoire de la Côte d’Azur
    Boulevard de l’Observatoire
    Nice, France
    Email:
    Frederic.Thevenin@oca.eu

    Tel: +33 4 92 00 30 26

    Christophe Lovis
    Observatoire astronomique de l’Université de Genève,
    51 Ch. des Maillettes,
    1290 Versoix, Switzerland
    Email:
    christophe.lovis@unige.ch

    Peter Grimley
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6383
    Email:
    pgrimley@partner.eso.org

    1
    Interest in our neighbouring Alpha Centauri star system has been particularly high since the recent discovery of an Earth-mass planet, known as Proxima b, orbiting the system’s third star — and the closest star to the Sun — Proxima Centauri. While the system’s larger stellar pair, Alpha Centauri A and B, appear to have a proper motion on the sky that is very similar to that of the smaller, fainter Proxima Centauri, it has not been possible to demonstrate that the three stars do actually form a single, gravitationally bound, triple system.

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker
    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    Now three astronomers, Pierre Kervella, Frédéric Thévenin and Christophe Lovis, have concluded that the three stars do indeed form a bound system. In the century since it was discovered, Proxima Centauri’s faintness has made it extremely difficult to reliably measure its radial velocity — the speed at which it moves towards and away from Earth. But now ESO’s planet-hunting HARPS instrument has provided an extremely precise measurement of Proxima Centauri’s radial velocity, and even greater accuracy has been achieved by accounting for other subtle effects [1].

    ESO/HARPS
    ESO 3.6m telescope & HARPS at LaSilla
    ESO 3.6m telescope & HARPS at Cerro LaSilla, Chile

    As a result, the astronomers have been able to deduce very similar values for the radial velocities of the Alpha Centauri pair and Proxima Centauri, lending credence to the idea that they form a bound system. Taking account of these new measurements, calculations of the orbits of the three stars indicate that the relative velocity between Proxima Centauri and the Alpha Centauri pair is well below the threshold above which the three stars would not be bound together by gravity.

    This result has significant implications for our understanding of the Alpha Centauri system and the formation of planets there. It strongly suggests that Proxima Centauri and the Alpha Centauri pair are the same age (about 6 billion years), and that in turn provides a good estimate of the age of the orbiting planet, Proxima b.

    The astronomers speculate that the planet may have formed around Proxima Centauri on a more extended orbit and then been brought to its current position, very close to its parent star, as a result of the close passage of Proxima Centauri to its cousins in the Alpha Centauri pair. Alternatively, the planet may have formed around the Alpha Centauri pair, and was later captured by the gravity of Proxima Centauri. If one of these hypotheses is correct, it is possible that the planet was once an icy world that underwent a meltdown and now has liquid water on its surface.

    Notes

    [1] Measurements of the stars’ velocities were made by observing specific features in their light known as spectral lines. Certain physical effects can shift the observed wavelengths of these lines, leading to incorrect measurements of the velocities. If a star has an unstable surface, it can cause what is known as convectiveblueshift of the spectral lines, while its gravity can lead to a gravitational redshift.
    More Information

    This research is presented in a paper to appear in the journal Astronomy and Astrophysics.

    The team is composed of P. Kervella, CNRS UMI 3386, University of Chile and LESIA, Paris Observatory; F. Thévenin, Côte d’Azur Observatory, France; and Christophe Lovis, Observatoire astronomique de l’Université de Genève, Switzerland.

    See the full article here .

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  • richardmitnick 10:44 am on October 12, 2016 Permalink | Reply
    Tags: , , , Proxima Centauri   

    From CfA: “Proxima Centauri Might Be More Sunlike Than We Thought” 

    Smithsonian Astrophysical Observatory
    Smithsonian Astrophysical Observatory

    October 11, 2016
    Christine Pulliam
    Media Relations Manager
    Harvard-Smithsonian Center for Astrophysics
    617-495-7463
    cpulliam@cfa.harvard.edu

    1
    An artist’s illustration depicts the interior of a low-mass star. Such stars have different interior structures than our Sun, so they are not expected to show magnetic activity cycles. However, astronomers have discovered that the nearby star Proxima Centauri defies that expectation and shows signs of a 7-year activity cycle. NASA/CXC/M.Weiss

    In August astronomers announced that the nearby star Proxima Centauri hosts an Earth-sized planet (called Proxima b) in its habitable zone. At first glance, Proxima Centauri seems nothing like our Sun. It’s a small, cool, red dwarf star only one-tenth as massive and one-thousandth as luminous as the Sun. However, new research shows that it is sunlike in one surprising way: it has a regular cycle of starspots.

    Starspots (like sunspots) are dark blotches on a star’s surface where the temperature is a little cooler than the surrounding area. They are driven by magnetic fields. A star is made of ionized gases called plasma. Magnetic fields can restrict the plasma’s flow and create spots. Changes to a star’s magnetic field can affect the number and distribution of starspots.

    Our Sun experiences an 11-year activity cycle. At the solar minimum, the Sun is nearly spot-free. At solar maximum, typically more than 100 sunspots cover less than one percent of the Sun’s surface on average.

    The new study finds that Proxima Centauri undergoes a similar cycle lasting seven years from peak to peak. However, its cycle is much more dramatic. At least a full one-fifth of the star’s surface is covered in spots at once. Also, some of those spots are much bigger relative to the star’s size than the spots on our Sun.

    “If intelligent aliens were living on Proxima b, they would have a very dramatic view,” says lead author Brad Wargelin of the Harvard-Smithsonian Center for Astrophysics (CfA).

    Astronomers were surprised to detect a stellar activity cycle in Proxima Centauri because its interior is expected to be very different from the Sun’s. The outer third of the Sun experiences a roiling motion called convection, similar to water boiling in a pot, while the Sun’s interior remains relatively still. There is a difference in the speed of rotation between these two regions. Many astronomers think the shear arising from this difference is responsible for generating the Sun’s magnetic activity cycle.

    In contrast, the interior of a small red dwarf like Proxima Centauri should be convective all the way into the star’s core. As a result, it shouldn’t experience a regular cycle of activity.

    “The existence of a cycle in Proxima Centauri shows that we don’t understand how stars’ magnetic fields are generated as well as we thought we did,” says Smithsonian co-author Jeremy Drake.

    The study does not address whether Proxima Centauri’s activity cycle would affect the potential habitability of the planet Proxima b. Theory suggests that flares or a stellar wind, both of which are driven by magnetic fields, could scour the planet and strip away any atmosphere. In that case, Proxima b might be like Earth’s Moon – located in the habitable zone, but not at all friendly to life.

    “Direct observations of Proxima b won’t happen for a long time. Until then, our best bet is to study the star and then plug that information into theories about star-planet interactions,” says co-author Steve Saar.

    The team detected the activity cycle using ground-based observations from the All Sky Automated Survey combined with space-based X-ray measurements by several missions, including Swift, Chandra, and XMM-Newton. Their results have been accepted for publication in the Monthly Notices of the Royal Astronomical Society and appear online.

    See the full article here .

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    About CfA

    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy. The long relationship between the two organizations, which began when the SAO moved its headquarters to Cambridge in 1955, was formalized by the establishment of a joint center in 1973. The CfA’s history of accomplishments in astronomy and astrophysics is reflected in a wide range of awards and prizes received by individual CfA scientists.

    Today, some 300 Smithsonian and Harvard scientists cooperate in broad programs of astrophysical research supported by Federal appropriations and University funds as well as contracts and grants from government agencies. These scientific investigations, touching on almost all major topics in astronomy, are organized into the following divisions, scientific departments and service groups.

     
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