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  • 摘要:

    In April 2018, a team composed of scientists and engineers from the Geneva Observatory and ESO were at the La Silla Observatory to commission HELIOS (HARPS Experiment for Light Integrated Over the Sun) [1]. This novel device was built under an agreement between ESO, the University of Geneva and the Centro de Astrofísica da Universidade do Porto [2].

    HELIOS is a solar telescope feeding the HARPS (High Accuracy Radial velocity Planet Searcher) instrument, which is attached to the ESO 3.6-metre telescope. HARPS is one of the most powerful planet hunters in existence and spends most nights monitoring stars for minute signals that indicate the presence of an exoplanet. HARPS has unparalleled accuracy and is regularly generating results that will present fresh challenges for future telescopes such as ESO’s Extremely Large Telescope.

    HELIOS will be able to feed sunlight into HARPS to achieve very high precision spectroscopy of the Sun for several hours per day [3]. As well as learning about the Sun itself, and in particular improving our understanding of stellar activity (which is the main limitation in the detection of Earth-twins using HARPS), the HELIOS project will lead to an improvement of exoplanet detection techniques.

    The large volumes of data from HELIOS will also allow very detailed investigations into the different HARPS instrumental effects and may lead to improvements in the precision of HARPS itself. This information could be transferred and applied to ESPRESSO (Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations), which is the successor to HARPS and is attached to ESO’s Very Large Telescope.

    The HELIOS project will run until the end of 2022.

    Notes

    [1] The commissioning team consisted of: Xavier Dumusque (Principal Investigator, Geneva), Pedro Figueira (co-Principal Investigator, ESO), François Wildi (system engineer, Geneva), Gaspare LoCurto (ESO), Thibault Pirson and Thibault Wildi (engineering students).

    [2] The project is led by the University of Geneva, through its Geneva Observatory, and includes as a partner the Centro de Astrofísica da Universidade do Porto, through its Instituto de Astrofísica e Ciências do Espaço.

    [3] The HELIOS observing facility consists of a lens that focuses an image of the Sun into an integrating sphere. Light exits the sphere through a 30-metre optical fibre connected to the HARPS calibration unit. The whole setup is enclosed in a weather-resistant and waterproof box topped by a plexiglass dome.

    来源机构: 欧洲南方天文台 | 点击量:13
  • 摘要:

    The digging of the foundations for the dome and telescope structure of ESO’s Extremely Large Telescope (ELT) has begun on Cerro Armazones — at an altitude of over 3000 metres in Chile's Atacama Desert. The work is being carried out by the ACe Consortium, consisting of Astaldi and Cimolai. These dramatic pictures were taken to mark this event by ESO photo ambassador Gerhard Hüdepohl, who used a drone to gaze down on Cerro Armazones.

    Dubbed ELT, this revolutionary new ground-based telescope concept will have a 39-metre main mirror and will be the largest optical/near-infrared telescope in the world: “the world’s biggest eye on the sky”. Construction is targeted for completion in time for first light in 2024.

    Working at such a high altitude is not easy, but the rewards will be great; this site is high, dry, and removed from light pollution. It will provide truly excellent seeing conditions, allowing astronomers to probe the mysteries of the cosmos as never before.

    The outline of the telescope’s main structure is clearly visible and, when completed, an 80-metre-high dome will cover this outline. The 55-metre diameter circular pit at the centre will eventually contain the foundation for the structures supporting the colossal 39-metre primary mirror that gives the ELT its name. The photo also clearly illustrates just how large the telescope will be; the various construction vehicles dotted around look small when compared to the imposing size of the ELT’s foundations, and the people scattered across the site are almost invisible.

    Cerro Armazones is only 22 kilometres from ESO’s current flagship observatory, the Very Large Telescope (VLT) — close enough that each will be visible from the other, and driving between the two will take roughly 30 minutes. This allows the ELT to be close to the support buildings and infrastructure currently used for the VLT. Cerro Armazones was actually almost chosen as the site for the VLT, but Cerro Paranal was chosen instead. However, with construction now underway, Cerro Armazones will soon have a telescope of its very own.

    来源机构: 欧洲南方天文台 | 点击量:26
  • 摘要:

    ESO has signed a contract with VDL ETG Projects B.V. (the Netherlands) for the manufacture, assembly, testing and delivery of the Segment Support Mechanics for the primary mirror of ESO’s Extremely Large Telescope (ELT). The segment supports together act as the backbone of the primary mirror, holding each of the 798 mirror segments in place. Sensors and actuators monitor and control each segment’s shape and position to very high accuracy.

    The contract was signed by Harrie Schonewille, Managing Director of VDL ETG Projects, Willem van der Leegte, President VDL and Xavier Barcons, Director General of ESO, at a ceremony at ESO Headquarters in Garching, Germany on 19 April 2018.

    When completed, the ELT’s primary mirror (M1) will be 39 metres in diameter and will consist of 798 hexagonal mirror segments. The hexagonal shape means that a common support structure can be used for all segments. Each segment will be connected to the back-structure by means of a segment support system. This is composed of three linkage mechanisms that balance the forces applied and hold the segment via 27 axial actuators and one lateral actuator. The shape of each segment can also be optimised by means of warping harness actuators. Each segment, some 1.4 metres across and weighing 250 kilograms, will be mounted on three position actuators.

    ELT first light is planned for 2024, when it will begin to tackle the biggest astronomical challenges of our time. The giant telescope is expected to allow the exploration of completely unknown realms of the Universe — it will be “the world’s biggest eye on the sky”.

    来源机构: 欧洲南方天文台 | 点击量:41
  • 摘要:

    The French optics company Safran Reosc has completed the first of six shells that will comprise the M4 deformable mirror system, which forms a fundamental part of ESO’s Extremely Large Telescope (ELT). When complete, the adaptive M4 mirror will be 2.4 metres in diameter but only 1.95 millimetres thick. This very thin mirror is one of the five main mirrors of the ELT’s optical system, with the main segmented mirror being 39 metres in diameter.

    Safran Reosc are manufacturing all six of the deformable shell mirrors that comprise the M4 mirror. Together, these 60-degree petal sections form the circular segmented M4 mirror. They will be mounted and supported in the adaptive mirror unit. Meanwhile, the Italian consortium AdOptica is manufacturing the complex adaptive support system needed for the M4.

    Deformable mirrors, such as the M4 mirror of the ELT, are key components of adaptive optics systems, which help reduce the effects of atmospheric distortions. Adaptive optics systems work by measuring atmospheric turbulence — often with the help of laser guide stars — and compensating for this turbulence by adjusting the shape of a deformable mirror.

    The actuators and controls in the adaptive support system will allow the ELT to make these corrections in real time. The system will also be able to correct for effects caused by the wind, which can sometimes deform the structure of the main telescope.

    The combination of the M4 mirror shells and their adaptive support systems will form part of the largest adaptive mirror unit ever made and means that images obtained by the ELT will be almost as sharp as those taken in space.

    来源机构: 欧洲39米望远镜(E-ELT) | 点击量:25
  • 摘要:

    ESO has signed a contract with the Spanish company IDOM Consulting, Engineering, Architecture SAU for the production of a major new component of ESO’s Extremely Large Telescope. The Prefocal Station will direct the light collected by the telescope’s huge optical system into science instruments and other test equipment. It also contains parts of the active optics system of the telescope [1].

    The contract was signed by Luis Rodríguez, President of IDOM, and the ESO Director General, Xavier Barcons, at a ceremony at ESO Headquarters in Garching, Germany, on 21 March 2018. As well as representatives of the company and ESO staff, the Consul General of Spain in Munich, Francisco Pascual de la Parte, was also welcomed to the ceremony.

    The Prefocal Station is a massive structure, standing over 12 metres high, which sits on one of the two platforms on either side of the Extremely Large Telescope’s giant tube structure. It is the last opto-mechanical component before the light from the telescope comes to a focus, hence the name.

    The Prefocal Station contains three movable mechanical arms that can pick off the light from stars. These will contain sensors to help precisely control the telescope’s pointing at objects in the sky. They will also feed information into the active optics system that keeps the telescope’s optics aligned and produces optimum image quality despite the constantly-changing effects of wind and other disturbances on the telescope.

    The Prefocal Station also includes a large movable flat mirror that reflects light into the huge science instruments that will be mounted on either side (HARMONI and METIS) and behind the Prefocal Station (MAORY and MICADO). A second deployable mirror is also available to feed the light to additional future science instruments as well as to a test and diagnostic system.

    Notes

    [1] The contract formally covers the Prefocal Station A Main System. It also contains an option for the possible future construction of a similar station for the ELT’s other instrument platform on the opposite side of the telescope’s tube. The main system is part of a larger system that contains additional components such as system test equipment, metrology equipment, and detectors.

    来源机构: 欧洲39米望远镜(E-ELT) | 点击量:17
  • 摘要:

    The conceptual design and scope of TMT’s Refrigerant Cooling System (REFR), which was executed and developed by a close Chinese-North American collaboration, successfully passed a recent conceptual design review. This system will be used to provide cooling to electronics enclosures mounted on the telescope structure. The system also maintains several TMT instrument enclosures at subzero temperatures to reduce thermal backgrounds for near-infrared observations.

    The review committee at the project office in Pasadena assessed that the REFR team successfully completed the conceptual design phase and is now ready to proceed to a combined Preliminary and Final Design Phases, provided that minor key actions are addressed. The formal review panel included TMT stakeholders and high-level international experts in industrial gases and cryogenics field, including representatives from Quantum Technology Corporation in Canada, and Microgate Engineering in Italy.

    Gelys Trancho, TMT senior system engineer, said after the review: “Today, the Refrigerant Cooling System passed a key milestone. The feedbacks from the review panel were positive on many fronts. The panel members recognized the hard work of the REFR team (TIPC and TMT) and their dedication to provide an excellent REFR system for TMT.”

    Several TMT adaptive optics and on-instrument wavefront sensing systems, including NFIRAOS, will be cooled well below ambient temperature to reduce the thermal background for near-infrared observations. As a result, TMT REFR system shall maintain these optical enclosures at a temperature of around -30°C (-22°F).

    The REFR system will also be used to cool electronics and other heat dissipating enclosures to ambient temperature (approximately 0°C or 32°F) at several locations on the telescope structure. If not controlled, the heat released from these electronics could generate convective motion of air pockets at different temperatures, creating turbulence across the optical light path that would degrade scientific performance.

    The key deliverables of this review included the REFR system requirements, design concept, interface requirements with the TMT’s summit facility, the science instruments and the AO system, as well as concepts for heat-exchange control and system maintenance. The REFR system must meet strict technical, environmental, functional and operational requirements. The safety of its operations must also be consistent with industry standards and best practices.

    The REFR team presented the result of their detailed trade-off study of candidate refrigerants, which showed that liquid carbon dioxide CO2 is the preferred cooling solution for TMT. It minimizes the heat dispersion from electronics and other equipment on the telescope. It provides efficient cooling at temperatures of both -30C and ambient, is nonflammable, and is compliant with the Montreal Protocol (an international treaty designed to protect the Earth’s atmosphere ozone layer).

    The REFR conceptual design phase is the result of an intensive consultation and peer review process involving the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences (TIPC), the TMT Systems Engineering Group, and the design team for the TMT Narrow Field AO System (NFIRAOS) at the Herzberg Astronomy and Astrophysics Research Centre in Victoria, Canada. The Technical Institute of Physics and Chemistry is one of the consortium institutes of the TMT-China partnership within TMT International Observatory.

    This successful REFR conceptual design has delivered a technically viable solution. Prototyping and design activities will soon begin to bring TMT’s refrigerant system to its next development phase, which is expected to be complete in late 2019.

    Note: Some parts of the TMT science instruments themselves, including detectors and optics for infrared instruments, must in many cases be cooled to lower cryogenic temperatures. Such cryogenic cooling was not covered by this review.

    来源机构: 美国三十米望远镜(TMT) | 点击量:23
  • 摘要:

    Assistant Minister Zed Seselja has launched the $7 million TAIPAN instrument at Siding Spring Observatory in North-Western NSW. TAIPAN is installed on the fully refurbished UK Schmidt Telescope currently operated by the Australian Astronomical Observatory. A cutting-edge positioning system using mini-robots called “Starbugs”, TAIPAN will measure up to 2 million galaxies and 3 million stars to make new discoveries about dark energy, dark matter, and galaxy and star formation and evolution.

    Today Assistant Minister for Science, Jobs and Innovation Senator the Hon Zed Seselja visited Siding Spring Observatory (near Coonabarabran, NSW) to inaugurate TAIPAN.

    “The AAO is a world leader in developing game-changing new astronomical instrumentation. We’ll be able to do an enormous amount of science that was barely conceivable a few years ago, thanks to the Starbug fibre positioners that are the cornerstone of TAIPAN”, said Dr Kyler Kuehn, TAIPAN Project Scientist at the AAO.

    TAIPAN is installed on the UK Schmidt Telescope (UKST), owned by the Australian National University (ANU) and managed by the AAO. The UKST has an aperture of 1.2 metres and a very wide-angle field of view. TAIPAN consists of a robot positioner operating over the 6-degree field of view of the UKST, moving 150 optical fibres simultaneously to align them with their target objects, with an accuracy of a few thousandths of a millimetre. TAIPAN includes a dedicated spectrograph, designed and built by the AAO, which splits the light captured by the Starbugs into its component colours.

    The UKST was commissioned in 1973 as a survey telescope, carrying out the first deep photographic surveys of the southern skies. Between 2001 and 2013 the 6dF (6-degree Field) multi-fibre-optic technology was used to gather detailed information on 120,000 galaxies and half a million stars over the whole southern sky. The UKST was refurbished between 2014 and 2016 to allow remote operations and the installation of TAIPAN.

    The TAIPAN fibre positioning system uses the AAO's novel “Starbug” technology, which enables repositioning of hundreds of fibres at once.

    “The ability to move all the fibres simultaneously gives us an enormous time-saving over 6dF’s one-at-a-time approach,” says Prof Fred Watson of the Australian Astronomical Observatory. “Fibre reconfiguration comes down from an hour to two or three minutes – amazing!”

    The TAIPAN instrument will be used to complete two new astronomical surveys, called the “Taipan galaxy survey” and the “FunnelWeb stellar survey”.

    The Taipan galaxy survey will obtain high quality spectra for 2 million galaxies. This will be the most comprehensive spectroscopic survey of the Southern Hemisphere ever undertaken. The main goals of the Taipan galaxy survey are to measure the present-day expansion rate of the Universe to 1% precision, to make the most extensive map of the position and motions of galaxies in the Local Universe, and to understand the role of mass and environment in the evolution of the galaxies.

    “The Taipan galaxy survey will determine both the age and size of the Universe with extraordinary precision. To do so, it will measure the position of 2 million galaxies and the velocities for 100,000 of those galaxies”, said Prof Matthew Colless, Director of the ANU Research School of Astronomy and Astrophysics and co-leader of the Taipan galaxy survey.

    “The survey will provide the benchmark for understanding galaxies in our local Universe,” says Prof Andrew Hopkins, AAO’s Head of Research and Outreach and co-leader of the Taipan galaxy survey. “We will provide unique insights into dark energy and dark matter that are only possible with a large area spectroscopic survey of this kind. This survey will be a touchstone for future projects with the largest telescopes in the world, and in space.”

    The FunnelWeb stellar survey, led by astronomers at UNSW Sydney and the ANU, will create an ambitious new database of spectra for 3 million stars in its first 3 years of operation. It will deliver a detailed spectral library for millions of stars in the Southern Hemisphere. The survey will provide an input catalogue for future generations of searches for new planets. It will also enable new maps and a new understanding of the structure of our home, the Milky Way galaxy.

    “The technology built into TAIPAN is revolutionary, because it allows all 150 Starbugs to independently move to new targets”, says Prof Chris Tinney, head of Exoplanetary Science at UNSW and co-leader of the FunnelWeb project. “This means we can reposition and observe another 150 stars roughly every 6 minutes. That means around 15,000 stars a night, or over a million stars a year. It’ll be the fastest survey of the stars of our Galaxy ever obtained!”

    The Australian Government has invested $6.37 million over four years to bring TAIPAN to fruition, including the UKST refurbishment, the Starbug fibre positioner system, and the spectrograph. But the work has had a long gestation.

    "TAIPAN represents the realisation of more than a decade of research and development by the team, since the Starbugs project inception in 2004. Work on this exciting technology continues, with a view to future astronomy instruments as well as possible industrial applications", said Dr Nuria Lorente, Senior Astronomy Instrumentation Software and Systems Engineer at the AAO.

    The TAIPAN instrument is a developmental prototype for an even more powerful instrument under development called MANIFEST. When MANIFEST is installed in the mid-2020s on what will, at that time, be the largest telescope in the world – the Giant Magellan Telescope – it will enable future generations of surveys of the faintest stars and galaxies in the sky.

    来源机构: 英澳天文台 | 点击量:38
  • 摘要:

    MSE and CFHT welcomed an expert panel of astronomers and engineers to their offices in Waimea in January, as the Project underwent its System-Level Conceptual Design Review. The review was chaired by Michael Strauss (Princeton), and the panel consisted of Ken Chambers (Hawaii), Scott Roberts (TMT), Rob Sharp (ANU, remote participant), and Hermine Schnetler (STFC). The Panel was asked:

    "to assess whether the science requirements will be met by the Level 1 requirements defined in the three “foundation” documents: OCD [Operations Concept Document], OAD [Observatory Architecture Document] and ORD [Observatory Requirements Document] as organized and presented. In addition, the review panel should appraise whether the conceptual design has a strong likelihood of success from a systems engineering standpoint. The system level work includes development of requirements (flow down and traceability), performance and technical budgets (derivations and allocations), interface definitions and verifications etc., and success is defined by meeting the stated science requirements."

    The evaluation spanned all aspects of the science, operations and technical development of MSE. The three day review included many incisive comments from the Panel on the science and design development of MSE to date, as well as the systems engineering methodology. These will prove to be invaluable as MSE progresses into the next phase of the project.

    The feedback from the Panel included several action items for which the Project is preparing responses. Prominent among these is the creation of a Design Reference Survey for MSE, that will be a major science development exercise over the next year, and on which there will be more news soon.

    In the words of the Panel:

    "the bottom line is that this project is in very good shape, and at an appropriate level of maturity for the end of the Conceptual Design phase. We have been very impressed by the level of sophistication that the MSE project team has brought to this project, and the tremendous amount of hard work that has been carried out thus far. This level of professionalism bodes well for the project as it enters the preliminary design phase."

    We thank the Panel for their time and feedback, and for playing a critical role in MSE's ongoing development. The System-Level review finished off a busy year for the Project, that has seen a previous 10 different subsystem Conceptual Design Reviews. 2018 will see the Project wrap up the conceptual design phase and move into the preliminary design phase. Stay tuned!

    来源机构: 加法夏望远镜(CFHT) | 点击量:29
  • 摘要:

    ESO has signed a contract with the engineering and construction company Abengoa Chile to build the ELT Technical Facility at ESO’s Paranal Observatory in northern Chile. This new facility will host the assembly and maintenance facilities for the mirrors of ESO’s Extremely Large Telescope (ELT), as well as all the coating, washing and stripping facilities needed to coat and maintain the reflectivity of the mirrors.

    The primary mirror of the ELT will consist of 798 separate reflective segments [1]. At the ELT Technical Facility, the polished segment assemblies will be coated and integrated with the edge sensors on the sides of each segment, to detect the position of each segment relative to its neighbours [2].

    Once the telescope is complete and in operation, each segment of the primary mirror will need recoating every 1.5 years to ensure its cleanliness and reflectivity. As there are 798 segments, the most efficient way to do this is to remove, clean, recoat, and replace two or three segments every single day.

    The ELT Technical Facility will also house the coating unit for the secondary and tertiary mirrors of the ELT, each of which measures around four metres in diameter.

    The facility will also be used for the initial assembly, integration and verification tasks of the mirrors, as well as for future recoating activities.

    After around three months of detailed design, construction of the building will begin in the second half of 2018 and will last 11 months. The building should be completed by July 2019.

    The signature event was held at the ESO Vitacura offices in Santiago, Chile, and the contract was signed by Sergio Adrian Morrone from Abengoa Chile and the ESO Director General, Xavier Barcons, in the presence of Willy Benz, ESO Council President, and Ambassador Gabriel Rodríguez, Director of Energy, Science and Technology and Innovation at the Chilean Ministry of Foreign Affairs. Also participating were ESO’s Representative in Chile, Fernando Comerón, as well as other officials from ESO and Abengoa.

    Notes

    [1] The primary mirror of the ELT will measure 39 metres in diameter and will consist of 798 segments. The segments are hexagonal in shape, which permits the use of a common support structure for all segments. The maximum corner to corner dimension for the segments is about 1.45 metres. Each segment will be able to move individually, forming an active optics system that ensures optimal image quality at all times.

    [2] These sensors are the most accurate ever used in a telescope and can measure relative positions to an accuracy of a few nanometres. They form a fundamental part of the very complex system that will continuously sense the locations of the ELT primary mirror segments relative to their neighbours and allow the segments to work together to form a perfect imaging system.

    More Information

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and by Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.

    来源机构: 欧洲南方天文台 | 点击量:18
  • 摘要:

    At its meeting on 7 March 2018, ESO Council decided to clarify the status of Brazil’s current relationship with the Organisation, for the benefit of both Brazil and ESO and their respective astronomical communities.

    Brazil’s accession to ESO was unanimously approved by ESO Council on 21 December 2010. To support Brazil in the period before ratification was completed, the Accession Agreement contained a series of interim arrangements. These offered, among others, the possibility for Brazilian industries to participate in ESO calls for tender (for contracts awarded after ratification), and for astronomers in Brazilian institutes to apply for observing time for ESO’s telescopes on the same basis as those from ESO Member States.

    The Accession Agreement was approved by the National Congress of Brazil on 14 May 2015, however, the conclusion of the accession process is still pending.

    Noting that the completion of the Accession Agreement is unlikely to happen in the near future, ESO Council has decided to suspend the process until Brazil is in a position to complete the execution of the Accession Agreement, possibly through a re-negotiation. With the unanimous support from all its Member States, ESO will remain open to welcome Brazil at any time. Meanwhile, the interim arrangements will be suspended as of 1 April 2018.

    As an international treaty approved by both Brazil and ESO Council, the Accession Agreement remains valid. ESO’s programmes and any ongoing Brazilian participation in project consortia are unaffected. The decision will be reflected in some modifications to ESO’s corporate image. ESO Council reiterated that Brazil continues to be a valuable potential partner of ESO and expressed its desire to welcome Brazil as a Member State in the future.

    来源机构: 欧洲南方天文台 | 点击量:24