TY - JOUR
AU - Gunn, Alastair
AB - Abstract A digest of some of the big stories from the past two months RAS launches new open access journal At the July 2021 National Astronomy Meeting, hosted online by the University of Bath, the Royal Astronomical Society announced the launch of a new open access journal. The provisional title of the Society's third journal is RAS Techniques and Instruments. It will be a gold open access publication focusing on instrumentation, data science, machine learning, software, and numerical and statistical methods in astronomy and geophysics. The editor-in-chief is Prof. Jonathan Tennyson (University College London), spectroscopist and theoretical molecular physicist. “It is an honour to be founding editor-in-chief of this new journal,” said Tennyson. “Numbers drive modern science, and RAS T&I will make data, software and numerical techniques as well as information on cutting-edge instruments available to as wide an audience as possible. In particular, RAS T&I will reflect the transformative nature of machine learning and artificial intelligence in all areas of astronomical and geophysical research.” RAS T&I will open for submissions in 2021, with first content published in 2022. bit.ly/2UU2Ixu Phosphine again: this time it's geology? Open in new tabDownload slide Venusian volcano Maat Mons. (NASA/JPL) Open in new tabDownload slide Venusian volcano Maat Mons. (NASA/JPL) The detection of phosphine on Venus may have been statistically unreliable or contaminated by a close-by spectral line of SO2. But another possibility has been suggested. Writing in the Proceedings of the National Academy of Sciences, Jonathan Lunine and Ngoc Truong (Cornell, USA) suggest the detection, if real, is telling us about the geology of Venus. If the interior harbours compounds containing P3– (phosphide), and explosive volcanic activity occurs, those phosphides can react efficiently with atmospheric sulphuric acid to form phosphine. bit.ly/3mEtYvu Wet world is just half the mass of Venus Open in new tabDownload slide Artist's impression: looking across the exoplanet ocean. (ESO/L Calçada/M Kornmesser/Acknowledgment: O Demangeon) Open in new tabDownload slide Artist's impression: looking across the exoplanet ocean. (ESO/L Calçada/M Kornmesser/Acknowledgment: O Demangeon) Using the European Southern Observatory's Very Large Telescope (VLT) in Chile, a team of astronomers led by Olivier Demangeon (Porto) has discovered an exoplanet only half the mass of Venus – the lightest ever detected using the radial velocity technique. The exoplanet orbits around nearby star L 98-59 and the team suggests it is possibly an ocean world lying within its host star's habitable zone. This makes it an attractive target for future observations of exoplanet atmospheres. Furthermore, the team discovered a fourth planet and suspects there is a fifth, in a zone at the right distance from the star for liquid water to exist on the surface. The research appears in Astronomy & Astrophysics. bit.ly/2UWONa5 New exoplanet type may show biomarkers A team headed by Nikku Madhusudhan (Cambridge, UK) has identified a class of exoplanet that could support life in its oceans. “Hycean” planets – hot, oceancovered planets with hydrogen-rich atmospheres – are more numerous and easier to detect than Earth-like planets. They can be up to 2.6 times larger than Earth with atmospheric temperatures up to 200 °C, but their oceanic conditions could be similar to those conducive for microbial life in Earth's oceans. Writing in The Astrophysical Journal, the team found that some trace terrestrial biomarkers would be detectable with spectroscopic instruments currently in development. bit.ly/3ks0zBO MUSE shows its PHANGS Open in new tabDownload slide (ESO/ALMA [ESO/NAOJ/NRAO]/PHANGS) Open in new tabDownload slide (ESO/ALMA [ESO/NAOJ/NRAO]/PHANGS) The Physics at High Angular resolution in Nearby GalaxieS (PHANGS) survey has released multiwavelength data from 19 spiral galaxies – including NGC 1300, shown here – in order to track the processes of star formation. PHANGS used MUSE, the Multi-Unit Spectroscopic Explorer on the Very Large Telescope at the European Southern Observatory (ESO) in Paranal, Chile, to collect some 15 million spectra of different galactic regions. The team will combine these data with observations from other facilities such as the Atacama Large Millimetre-submillimetre Array and, in future, the James Webb Space Telescope and ESO's Extremely Large Telescope. bit.ly/3mP7Xdp New: the Caroline Herschel Medal Open in new tabDownload slide (Caroline Herschel engraving: RAS/SPL) Open in new tabDownload slide (Caroline Herschel engraving: RAS/SPL) The visit to the UK of German chancellor Angela Merkel in July brought the announcement of a new medal for outstanding research in astrophysics. The Caroline Herschel Medal will be awarded to a woman in the UK or Germany, in alternate years, the winner receiving £10 000 to support her research. The RAS and the Astronomische Gesellschaft (AG) will administer the award, which is supported financially by the UK government. “We are delighted to support this initiative recognizing … the long-standing cooperation between our nations,” said RAS president Prof. Emma Bunce. bit.ly/3ym9VnD Interstellar objects in the Oort Cloud In the Oort Cloud – the shell of debris in the furthest reaches of the solar system – interstellar objects outnumber objects originating from the vicinity of the Sun. That's the conclusion of a new study by Amir Siraj and Avi Loeb (CfA) which is published in Monthly Notices of the Royal Astronomical Society. The authors assess the implications of the observational constraints on interstellar object abundance set by asteroid 2I/Borisov. The abundance of these objects also suggests that much more debris is left over from the formation of planetary systems than previously thought. bit.ly/3DqFQHm Light from far side of black hole Open in new tabDownload slide (Dan Wilkins) Open in new tabDownload slide (Dan Wilkins) Dan Wilkins (Stanford) and colleagues report on XMM-Newton (ESA) and NuSTAR (NASA) X-ray observations of the central black hole (pictured in this artist's impression) in spiral galaxy I Zwicky 1, about 800 million light-years distant. Writing in Nature, the authors describe X-ray flashes from the black hole's “corona” – the inner part of the accretion disc. A series of bright X-ray flares, probably associated with magnetic reconnection events, were followed after a short delay by additional smaller flashes. The team suggests this is due to space-time warping close to the black hole and the delayed flares are the first direct observation of light reflected off the accretion disc from behind the black hole. go.nature.com/3gJn8AZ Backup resolves Hubble trouble NASA's Hubble Space Telescope lost about a month of operations in June/July but is now functioning normally. The problem, starting on 13 June, was caused by a degrading memory module in the observatory's payload computer, which controls and coordinates the science instruments. After Hubble's main computer stopped receiving a “keep-alive” signal from the payload computer, it placed all science instruments in safe mode. There is a backup payload system, but the swap required the instruments to be switched to use alternative interfaces and new software had to be uploaded to the backup computer. Hubble returned to science operations on 17 July. bit.ly/3yBvmS5 The big picture: Climate hot spot Open in new tabDownload slide (Contains modified Copernicus Sentinel data 2021, processed by ESA, CC BY-SA 3.0 IGO) Open in new tabDownload slide (Contains modified Copernicus Sentinel data 2021, processed by ESA, CC BY-SA 3.0 IGO) The release of the 6th Assessment Report of the Intergovernmental Panel on Climate Change coincided with reports of an extensive fire on the Greek island of Evia, shown here on 11 August. This false-colour Copernicus Sentinel-2 image shows vegetation in bright red; the brown and green areas are the scar from the wildfires that consumed more than 50 000 hectares. The IPCC scientific assessment of the state of our climate (www.ipcc.ch) highlights the unequivocal human influence on our climate, which is warming at unprecedented rates and will continue to do so, as will the frequency of extreme climate events including heatwaves and drought. bit.ly/3mHGPx9 Apply for research fellowship now The RAS is seeking applications for a research fellowship, to start next year. Outstanding candidates in the disciplines advanced by the RAS – astronomy, solar system science, geophysics and closely related areas – should apply by 23:59 (BST) on 15 October 2021. Full details are on the RAS website. bit.ly/3BjGuVi 100 space start-ups in the UK ESA has now supported 100 fledgling space companies in the UK. The 100th is Skyfarer, which is developing the UK's first autonomous drone delivery network for medical supplies, using facilities at ESA Business Incubation Centre UK at Space Park Leicester in the East Midlands, supported by ESA, the UK Space Agency, the Science and Technology Facilities Council and the University of Leicester. bit.ly/3gGEDCb Aurorae eat mesospheric ozone The phenomenon that causes aurorae also depletes mesospheric ozone. That's the conclusion of a study headed by Yoshizumi Miyoshi (Nagoya University, Japan) in Nature's Science Reports. The team observed high-latitude electron precipitation with the EISCAT radar, the Japanese spacecraft Arase, and an all-sky camera network. Their modelling showed that auroral electrons can reach 60 km altitude, where mesospheric ozone lies, depleting it by more than 10%. bit.ly/2Wy62yI TESS and Gaia map red giants NASA's Transiting Exoplanet Survey Satellite (TESS) has been used to investigate the distribution of red giant stars. Publishing in The Astrophysical Journal, Marc Hon (University of Hawaii) and colleagues describe mapping 158 505 examples across the sky using artificial intelligence to search TESS data for asteroseismological oscillations. Data from ESA's Gaia mission was then used to determine the distance to each. The results confirmed a fundamental prediction: younger, higher-mass stars lie closer to the plane of the Milky Way. go.nasa.gov/3ypZtf8 New CEO for UK Space Agency Open in new tabDownload slide Open in new tabDownload slide Paul Bate has been appointed chief executive officer of the UK Space Agency, taking up the role on 6 September. Bate has a PhD in particle physics and previously worked in the Civil Service and for healthcare group Babylon Health. “These are exactly the skills we need as we seek not just to grow our space sector, but to ensure that the benefits of our drive to cement the UK as a world-leading space nation reach all our communities,” said science minister Amanda Solloway. bit.ly/3sTsUVA Undergraduate Tomkins Prize The RAS is pleased to announce that Darcey Bower of the University of Liverpool has won the 2021 Patricia Tomkins Undergraduate Prize for her project “Building a magnetic gradiometer as a tool for geophysics outreach”. Bower is a geology and geophysics undergraduate who hopes to work in environmental geophysics. The runner-up was Lawrence Bissell of the University of Cambridge for his project “The HiSS (High-resolution Spectrograph in Space) CubeSat design study”. bit.ly/3kxRuYu Royal Society awards for Fellows Congratulations to RAS Fellows honoured by the Royal Society. Prof. Dame Jocelyn Bell Burnell receives the Copley Medal for her work on the discovery of pulsars. She has donated the £25 000 gift to the Institute of Physics's Bell Burnell Graduate Scholarship Fund. Prof. Carlos Frenk CBE won the Rumford Medal for his work on structure in the early universe. Congratulations also to Prof. Richard Horne, head of space, weather and atmosphere at the British Antarctic Survey, and to Gregory Houseman, emeritus professor of geophysics at the University of Leeds, both elected as Fellows of the Royal Society earlier this year. bit.ly/38nq81u Continental volcanoes cool us Weathering of silicate rocks by CO2 dissolved in rain, combined with subduction to return carbon-bearing minerals to the mantle, acts to stabilize surface temperatures on Earth. Now a team led by Thomas Gernon (Southampton), has combined plate tectonic reconstructions with machine learning algorithms to determine that continental volcanic arcs such as the Andes have been the most important driver of weathering intensity over the past 400 million years. The findings are published in Nature Geoscience. bit.ly/3gHpHni Two peas from the same icy pod Quanzhi Ye (University of Maryland, USA) and colleagues have used HST observations of the disintegrating comet ATLAS (C/2019 Y4) to suggest that it shares an orbital path and a parent body with the Great Comet of 1844 (C/1844 Y1). They both probably come from a kilometre-wide progenitor that split during its previous perihelion passage, and would have been a spectacular sky object some 5000 years ago. The paper appears in The Astronomical Journal. bit.ly/2Ws8gAl ALMA spots signs of baby exomoons The first evidence of exoplanet moons in formation has been gathered by ALMA. Led by Myriam Benisty (University of Grenoble, France), a research team found evidence of a circumplanetary disc surrounding exoplanet PDS 70c, one of two Jupiter-like planets in the PDS 70 system. The disc is about 1 au across, with enough mass to form three satellites the size of our Moon. The results are published in The Astrophysical Journal Letters. bit.ly/3gKvPLA Alien eyes on Earthlings? Using ESA's Gaia eDR3 catalogue, Lisa Kaltenegger (Cornell University) and Jackie Faherty (American Museum of Natural History) have identified 2034 nearby star systems, within 326 light-years, from which Earth could be detected from its solar transits. The results, presented in Nature, show that 1715 star systems could have spotted Earth since human civilization began about 5000 years ago. bit.ly/3ksKNXm Flickering could find black holes Colin Burke (University of Illinois at Urbana-Champaign) and colleagues, reporting in Science, have found a characteristic timescale in the pattern of flickering from actively feeding supermassive black holes (SMBH), that tightly correlates with the mass of the SMBH. They then found the same relationship for accreting white dwarfs and hope that the method can be used to predict the flickering signal from currently elusive intermediate mass black holes. bit.ly/3zvCyjC Hello, goodbye This is the last issue of A&G to have the benefit of Paul Johnson's work as designer, production editor and chief sub. If you have written for the magazine, you will know that he has made your work look enticing on the page, making the most of figures and images and sharpening headlines. He has also provided a welcome reality check, injecting humour and a human touch throughout. Paul has been integral to the success of the magazine since it launched in 1997, something he has continued to the end by supporting his very capable successor in the role, James Hannah. I wish Paul a long and happy retirement. Sue Bowler, editor News from NAM 2021 This year's National Astronomy Meeting, held online in July, shared research results presented at the meeting, from the origins of the universe to the secret of surviving a supernova. Other press briefings during the meeting focused on community affairs, as well as the launch of a new RAS journal and a new medal (see items on News pages). Open in new tabDownload slide Open in new tabDownload slide The Wednesday lunchtime session, Going Green, explored ways that scientists in our field can work more sustainably and was very well attended. The panel, chaired by Hannah Dalgleish (University of Oxford) with co-chairs Abigail Frost (KU Leuven) and Manisha Shrestha (Liverpool John Moores University), considered alternatives to international air travel to astronomical facilities and ways to make high-performance supercomputing less demanding of energy, among other topics. The focus on sustainability is growing across our sciences; the grassroots organization Astronomers for Planet Earth has written an open letter to astronomy institutions, now signed by more than 2800 people, and the RAS has signed the UN declaration Climate Neutral Now. NAM was also where the RAS announced the results of a community survey on bullying and harassment. 650 astronomers and geophysicists responded; their experiences paint a dispiriting picture. 44% have suffered bullying and harassment at work in the past year, and the figures are worse for those from minority groups – by disability, ethnicity or sexuality – and for women. “The results are very concerning and we must act to change this unacceptable situation,” said RAS president Emma Bunce. “We are committed to working alongside the community to urgently improve the environment in astronomy and geophysics.” The survey was commissioned by the RAS Committee for Diversity in Astronomy & Geophysics (CDAG) to explore these issues and the wider workplace culture. It will be published in full later this year. “Our RAS community is increasingly diverse, yet far from equitable,” noted Natasha Stephen, CDAG chair. “CDAG will work with RAS Fellows and the wider field to understand and tackle these systemic problems.” Áine O'Brien, RAS diversity officer, concurred: “This is the first time data like these have been collected in our field. It's bleak, sadly somewhat unsurprising, but is unequivocal evidence to show we need to improve the workplace culture in academia. We have a well-reported diversity problem in STEM and this does nothing to help. Women and minorities are feeling pushed out.” unfccc.int/climate-action/climate-neutral-now Black holes block star growth A combination of machine learning and cosmological simulations (EAGLE, Illustris and IllustrisTNG) matched with real-world data in the Sloan Digital Sky Survey indicates that the mass of the supermassive black holes within a galaxy is the best marker of whether a galaxy becomes quiescent, or carries on making stars at a steady rate. PhD student Joanna Piotrowska (University of Cambridge) said at NAM: “The simulations predict exactly what we see in the real universe: these monster objects force their host galaxies into a kind of semi-retirement from star formation.” bit.ly/3Bj7Wmf Cosmic kick for supernovae Open in new tabDownload slide (F Rodríguez Montero) Open in new tabDownload slide (F Rodríguez Montero) Cosmic rays from supernova explosions may give these explosions a greater impact on their surroundings than previously thought. Numerical simulation of the shockwaves from supernovae, led from the University of Oxford, suggest that the cosmic rays enhance the energy that the gas outflows can bring to the interstellar medium at a key stage in the evolution of the explosion. PhD student Curro Rodríguez Montero said at NAM: “When the supernova cannot gain more momentum from the conversion of its thermal energy to kinetic energy, we found that cosmic rays can give an extra push to the gas, allowing for the final momentum imparted to be up to 4–6 times higher than previously predicted.” This supernova simulation image shows hot and cold patches of gas (white/green) in the bubble and the filamentary structure of cosmic rays (blue) around the shell of the supernova remnant. bit.ly/386iV5N BIT better and cheaper than HST A balloon-borne telescope will rival the resolution of the Hubble Space Telescope at a fraction of the price, and will stay above the bulk of the atmosphere for months on end. SuperBIT, the Superpressure Balloon-borne Imaging Telescope, uses a huge helium balloon to carry a high-resolution wide-field 0.5 m telescope to an altitude of 40 km. The telescope measures light from the near-infrared to near-ultraviolet (900–300 nm) and, on its first flight in 2022, will make precise weak gravitational lensing measurements of gravity clusters. Open in new tabDownload slide The BIT telescope before a test launch in 2015. (Steven Li) Open in new tabDownload slide The BIT telescope before a test launch in 2015. (Steven Li) NASA and the Canadian Space Agency are working with the universities of Durham (UK), Toronto (Canada) and Princeton (USA) to develop this $5 million project. PhD student Mohamed Shaaban (University of Toronto) spoke at NAM: “New balloon technology makes visiting space cheap, easy and environmentally friendly. SuperBIT can be continually reconfigured and upgraded, but its first mission will watch the largest particle accelerators in the universe: collisions between clusters of galaxies.” sites.physics.utoronto.ca/bit Film goes ‘Beyond Visible Noise’ Weak sound waves that travel through plasma near Earth are the basis of a short film, Beyond Visible Noise, which premiered at NAM. Martin Archer (Imperial College London) described how he worked with spoken-word artists and film-makers to use routine data recordings in creative ways. The film combines processed versions of the sounds with poetry and imagery, as part of the Experimental Words project to link poets and scientists. experimentalwords.com Untangling solar activity Open in new tabDownload slide (Left) Magnetic loops on the Sun, as captured by NASA's Solar Dynamics Observatory. (Right) The image has been processed to highlight the edges of each loop and make the structure clearer. (NASA's Goddard Space Flight Center/SDO) Open in new tabDownload slide (Left) Magnetic loops on the Sun, as captured by NASA's Solar Dynamics Observatory. (Right) The image has been processed to highlight the edges of each loop and make the structure clearer. (NASA's Goddard Space Flight Center/SDO) Twisted magnetic field lines play an important role in solar activity, transferring energy from the Sun's interior to its outer layers and beyond. Researchers from the University of Durham, the University of Glasgow and INAF-Osservatorio Astrofisico di Catania (Italy) have now developed a direct measurement of magnetic entanglement that indicates the field lines are already twisted when they emerge from the photosphere. The results, taken at 10 active regions, suggest that the twisting arises in the convection zone below. Christopher Prior (University of Durham) presented the results at NAM: “We anticipate that magnetic winding will become a staple quantity in the interpretation of magnetic field structure from observational data.” bit.ly/3gpr1uX Solar Orbiter sails through a comet's tail Comet C/2019 Y4 (ATLAS) disintegrated in early 2020, a process observed by the Hubble Space Telescope. By chance, the remains of the comet lay in the path of ESA's latest spacecraft heading for the Sun, Solar Orbiter. “This is the first time we've travelled through the wake of a comet that's disintegrated,” said Tim Horbury (Imperial College London), principal investigator for the spacecraft's magnetometer. “It's another example of the kind of high-quality fortuitous science we can do with Solar Orbiter.” The mission team planned to use the spacecraft's instruments, designed to measure particles and electric and magnetic fields, to investigate comet ATLAS's dust and ion tails; once it disintegrated, they kept to the plan. The team had expected that the interplanetary magnetic field carried by the solar wind would drape around the comet, with a weaker field in the tail. They found that the remains of the comet did not give a strong signal as expected from an intact comet; instead there were episodes of waves in the magnetic field, and patches of dust, as the spacecraft passed through. “This is an exciting opportunity for us to study the make-up and structure of comet tails in unprecedented detail,” said Lorenzo Matteini (Imperial College London), who spoke at NAM. bit.ly/3kaHcgs Mars: Meteorites and dust Open in new tabDownload slide False-colour image of a martian meteorite, taken by the Opportunity rover in 2009. (NASA) Open in new tabDownload slide False-colour image of a martian meteorite, taken by the Opportunity rover in 2009. (NASA) Instruments to be used on the ExoMars rover Rosalind Franklin are being tested on the Natural History Museum's meteorite collection, in order to streamline the identification of meteorites on Mars. “Meteorites act as a witness plate across geological time. Generally, the surfaces of Mars we are exploring are incredibly ancient,” said PhD student Sara Motaghian (NHM and Imperial College London), who spoke at NAM. “There have been billions of years for the surface to accumulate these meteorites and lock in information from across Mars's past.” Mars rovers have found roughly one meteorite for every kilometre travelled, so it is likely that Rosalind Franklin will come across them. The NHM team aims to identify characteristic features of meteorites using multispectral imaging with the PanCam instrument, to speed up recognition. bit.ly/3kfhGqt • Researchers modelling the effects of a planet-wide dust storm on Mars at the equinox in 2018 have found that it affected northern and southern hemispheres in different ways. Paul Streeter (Open University), with colleagues from NASA and the Russian Academy of Sciences, combined climate modelling with data from ESA's ExoMars Trace Gas Orbiter and NASA's Mars Reconnaissance Orbiter. Results suggest that the storm practically destroyed the south polar vortex, resulting in the temperature rising and wind speeds falling as spring came early. In the north, autumn came as expected, but the polar vortex became more symmetrical – something the team ascribes to the heavy dust load in the atmosphere damping down atmospheric waves arising from the northern hemisphere topography. bit.ly/2WaaHY9 Small stars have smaller mountains Neutron stars may be even closer to perfect spheres than had been thought, according to modelling presented at NAM by PhD student Fabian Gittins (University of Southampton) and published in part in Monthly Notices of the RAS. Gittins and his team modelled realistic neutron stars and investigated the role of the ultradense neutron-star material in making mountains. They found that the tallest mountain would be only a fraction of a millimetre above the surrounding surface, in contrast to the few centimetres previously suggested. Older models assumed that the whole of the surface would need to be close to breaking point before the mountains collapsed; this result comes from a more physically realistic approach. The outcome suggests that it may be more difficult than anticipated to detect gravitational waves from single rotating neutron stars. bit.ly/3kkTuD6 Star death kills planetary life too Stars like the Sun, of modest mass, end their lives as white dwarfs, some of which have orbiting planets. But life on those planets is unlikely to have survived the star's evolution to that stage, according to a study published in Monthly Notices of the RAS by Dmitri Veras (University of Warwick), who spoke at NAM, and Aline Vidotto (Trinity College Dublin). The problem lies in stellar winds during the red-giant phase. The team modelled winds from 11 types of stars with masses of 1–7 times that of the Sun. The combination of the changes to a planet's orbit as its star loses mass and swells, and the stronger and variable winds from red giants, means that a planet's magnetosphere may not be a good enough shield from stellar particles. They suggest that a planet would be protected only if its magnetic field were at least 100 times as strong as Jupiter's. And during the giant branch phase, the habitable zone would move outwards, as would any orbiting planets. But the planets would move more slowly, bringing problems for any life existing there. 10.1093/mnras/stab1772 © 2021 Royal Astronomical Society This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - News in Astronomy & Geophysics – October 2021
JF - Astronomy & Geophysics
DO - 10.1093/astrogeo/atab085
DA - 2021-10-01
UR - https://www.deepdyve.com/lp/oxford-university-press/news-in-astronomy-geophysics-october-2021-TPNIT7B9fa
SP - 5.4
EP - 5.9
VL - 62
IS - 5
DP - DeepDyve
ER -