DOCSLIB.ORG

The Small Telescopes Still Useful for the Astrometry

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Small Telescopes Still Useful for the Astrometry The Small Telescopes Still Useful for the Astrometry Magda Stavinschi Astronomical Institute of the Romanian Academy What is the Astrometry? •It provides the positionand, by extension, the dimensions and the shapes of the celestial bodies. •As the stars change their positions in time, it has to describe their motion. •It allows us to determine the geometrical and dynamical properties of the bodies from our Universe. 1 To measure the motion of the closest objects we need to materialize a fixed RS on the sky. Quasars and distant galaxies: ideal fiducial points for RF RS = theoretic concept, materialized by a RF Continuous and more and more precise astrometric observations Star positions determined for Hipparchus (190 BC œ 120 BC) years by GB observations, within the framework of a large international campaign, known as "Carte duciel". Catalogues of star positions with greater and greater accuracy 2 HIPPARCOS (High Precision Parallax Collecting Satellite) first space experiment fully dedicated to astrometry. HIPPARCOS mission 1989 - 1993 •F56 RS was replaced by a CRS based on the positions of extragalactic radio sources => ICRS. •Epoch = 1998, January 1 •consistent with FK5 - S at J 2000.0. •materialized by equatorial coordinates of extragalactic radio sources observed by VLBI. •based on a kinematical definition (assuming that the visible Universe does not rotate). HIPPARCOS system coincides • with the principal axes of the ICRS at + 0.6 mas • with individual p.m. consistent with an inertial system at +0.25 mas/yr. 3 HIPPARCOS catalogue: - 118,218 stars (≈ 3 stars/square degree) - astrometric parameters - photometric information The astrometric precision in position, p.m. & parallax of order 1 mas or mas/yr, or better for the brighter stars The mean magnitude Hp = 8.7 Half of the catalogue lies in the interval 8 < Hp < 9.5. It makes the accessible universe 8 times larger than expected from the nominal mission . HIPPARCOS catalogue => TYCHOcatalogue, (1 million of stars) => TYCHO 2 (3 millions stars) Mean value of internal standard errors: •25 mas for the position components •0.10 magfor BT-VT colour index 4 ACHIEVEMENTS •predict the impacts of Comet Shoemaker-Levy 9 on Jupiter •identified stars that will pass close to the Sun •established the distances of stars possessing planets •discovered that the Milky Way is changing shape •identified a group of stars that invaded our Galaxy when it was young •altered the cosmic distance scale, making the Universe bigger and younger •confirmed Einstein's prediction of the effect of gravity on starlight What about the future? As HIPPARCOS was not enough, the astronomers like to reach better and better accuracy as soon as possible. Other missions are ready to be launched 5 GAIA Earth or Mother Earth composition, formation and evolution of our Galaxy by mapping with unprecedented precision the stars positions, p. m. & parallaxes of at least 4 - 50 million objects down to V = 15 mag accuracy better than 10 mas along with multi-colour multi-epoch photometry of each object. It could offer the possibility to detect the presence of Earth-like planets around stars within 20 pc LAUNCH DATE: Dec-2011 MISSION END: 2020 317 million Euros OBJECTIVES: The largest and most precise three dimensional chart of our Galaxy by providing unprecedented positional and radial velocity measurements for about one billion stars in our Galaxy and throughout the Local Group. 6 Additional scientific products •detection and orbital classification of tens of thousands of extra-solar planetary systems, •a comprehensive survey of objects ranging from huge numbers of minor bodies in our SS, through galaxies in the nearby Universe, to some 500000 distant quasars • number of stringent new tests of general relativity and cosmology It is the GB Astrometry still useful? WG FUTURE DEVELOPMENT OF THE GB ASTROMETRY founded in 2000 7 FDGBA PROJECTS A FOLLOW-UP PROGRAM FOR THE SPACE ASTROMETRY PROJECT GAIA W. Thuillot (1) & M. Stavinschi (2) (1)Institut de mécanique céleste et de calcul des éphémérides, Paris Observatory (2) Astronomical Institute of the Romanian Academy, Bucharest 8 The Solar System WG of GAIA(SSWG), coordinated by F. Mignard (Observatoire de la Cote d'Azur, France) and V. Zappala (Torino Observatory), undertakes exploratory studies for the observation program of the solar system by GAIA. Within this framework it plans to constitute a network for GB observations to follow-up GAIAwith the principal aim to confirm new target detections by GAIA and to carry out any astrometric measurements necessary for the improvement of the orbital elements and the cataloguing of these objects. Robotic telescopes In France, ARAGOproject (PI M. Boër, CESR/OMP Toulouse) whose speed of pointing will make it possible to observe on alarm for multiple programs, appears perfectly well suited to this type of task. Mainly dedicated to the study of the transitory events, Gamma Ray Bursts in particular, this project has included a contribution for GAIA follow-up obs. within the whole of the programs which it is envisaged to carry out. 9 Conventional telescopes These projects will be certainly far from providing an adequate cover of the sky in longitude and latitude, and their number will be insufficient to combat the weather risks. Telescopes of the 1-2m class will be particularly well suited, mainly due to access to these telescopes being more flexible than that for larger telescopes. CCD cameras on these telescopes are generally well suited for accurate astrometry of fast and eventually faint objects. Smaller telescopes could also be used for the brighter objects Mutual phenomena of Uranus satellites in 2007-2008 and further observations in network November 15-18, 2006, Paris Institut de Mécanique Céleste et de Calcul des Éphémérides Several astronomical studies require a large network of observers in order to acquire enough data of rare phenomena or to observe objects on alert or for a follow-up. 10 •the observation of the mutual events of the satellites of Uranus (2007-2008, only every 42 years), of the Jovian ones in 2009, the Saturnian ones in 2010 & any event involving asteroids for the study of natural satellites systems or double asteroids •the preparation for ground-based follow-up observations needed for GAIA other possible objectives for GB astrometry Solar system • Observation of minor planet positions for the determination of the masses of perturbing bodies • Observations of Earth-cruisers, for which one needs to update frequently the orbits • Bulk observations of newly discovered objects in order to get good orbits for recognition purposes • Observation of small planetary satellites using mask technique to dim the luminosity of the planet 11 Stars and stellar systems: • Observation of close binaries by speckle interferometry. The large number of these objects and their potential obtained data for determining stellar masses call for more instruments devoted to speckle interferometry. • Determination of stellar diameters by speckle interferometry or using occultations by the Moon. • Photometry of variable stars, in particular eclipsing binaries, which permits to determine stellar masses. • Recognition of stars and determination of their p.m. in highly crowded fields badly conditioned for space astrometry. Last but not least there are the educational efforts for the training of a new generation of astrometrists, now before the launching of new space specialized missions and the processing of a huge amount of data collected so far. 12 CONCLUSIONS YY EE SS The Small Telescopes are still useful for the Astrometry 13.
Load more

Recommended publications
  • HD 97658 and Its Super-Earth Spitzer & MOST Transit Analysis and Seismic Modeling of the Host Star
    The space photometry revolution CoRoT3-KASC7 joint meeting HD 97658 and its super-Earth Spitzer & MOST transit analysis and seismic modeling of the host star Valerie Van Grootel (University of Liege, Belgium) M. Gillon (U. Liege), D. Valencia (U. Toronto), N. Madhusudhan (U. Cambridge), D. Dragomir (UC Santa Barbara), and the Spitzer team 1. Introducing HD 97658 and its super-Earth The second brightest star harboring a transiting super-Earth HD 97658 (V=7.7, K=5.7) HD 97658 b, a transiting super-Earth • • Teff = 5170 ± 50 K (Howard et al. 2011) Discovery by Howard et al. (2011) from Keck- Hires RVs: • [Fe/H] = -0.23 ± 0.03 ~ Z - M sin i = 8.2 ± 1.2 M • d = 21.11 ± 0.33 pc ; from Hipparcos P earth - P = 9.494 ± 0.005 d (Van Leeuwen 2007) orb • Transits discovered by Dragomir et al. (2013) with MOST: RP = 2.34 ± 0.18 Rearth From Howard et al. (2011) From Dragomir et al. (2013) Valerie Van Grootel – CoRoT/Kepler July 2014, Toulouse 2 2. Modeling the host star HD 97658 Rp α R* 2/3 Mp α M* Radial velocities Transits + the age of the star is the best proxy for the age of its planets (Sun: 4.57 Gyr, Earth: 4.54 Gyr) • With Asteroseismology: T. Campante, V. Van Eylen’s talks • Without Asteroseismology: stellar evolution modeling Valerie Van Grootel – CoRoT/Kepler July 2014, Toulouse 3 2. Modeling the host star HD 97658 • d = 21.11 ± 0.33 pc, V = 7.7 L* = 0.355 ± 0.018 Lsun • +Teff from spectroscopy: R* = 0.74 ± 0.03 Rsun • Stellar evolution code CLES (Scuflaire et al.
    [Show full text]
  • Asteroseismology with Corot, Kepler, K2 and TESS: Impact on Galactic Archaeology Talk Miglio’S
    Asteroseismology with CoRoT, Kepler, K2 and TESS: impact on Galactic Archaeology talk Miglio’s CRISTINA CHIAPPINI Leibniz-Institut fuer Astrophysik Potsdam PLATO PIC, Padova 09/2019 AsteroseismologyPlato as it is : a Legacy with CoRoT Mission, Kepler for Galactic, K2 and TESS: impactArchaeology on Galactic Archaeology talk Miglio’s CRISTINA CHIAPPINI Leibniz-Institut fuer Astrophysik Potsdam PLATO PIC, Padova 09/2019 Galactic Archaeology strives to reconstruct the past history of the Milky Way from the present day kinematical and chemical information. Why is it Challenging ? • Complex mix of populations with large overlaps in parameter space (such as Velocities, Metallicities, and Ages) & small volume sampled by current data • Stars move away from their birth places (migrate radially, or even vertically via mergers/interactions of the MW with other Galaxies). • Many are the sources of migration! • Most of information was confined to a small volume Miglio, Chiappini et al. 2017 Key: VOLUME COVERAGE & AGES Chiappini et al. 2018 IAU 334 Quantifying the impact of radial migration The Rbirth mix ! Stars that today (R_now) are in the green bins, came from different R0=birth Radial Migration Sources = bar/spirals + mergers + Inside-out formation (gas accretion) GalacJc Center Z Sun R Outer Disk R = distance from GC Minchev, Chiappini, MarJg 2013, 2014 - MCM I + II A&A A&A 558 id A09, A&A 572, id A92 Two ways to expand volume for GA • Gaia + complementary photometric information (but no ages for far away stars) – also useful for PIC! • Asteroseismology of RGs (with ages!) - also useful for core science PLATO (miglio’s talk) The properties at different places in the disk: AMR CoRoT, Gaia+, K2 + APOGEE Kepler, TESS, K2, Gaia CoRoT, Gaia+, K2 + APOGEE PLATO + 4MOST? Predicon: AMR Scatter increases towards outer regions Age scatter increasestowars outer regions ExtracGng the best froM GaiaDR2 - Anders et al.
    [Show full text]
  • Gaianir Combining Optical and Near-Infra-Red (NIR) Capabilities with Time-Delay-Integration (TDI) Sensors for a Future Gaia-Like Mission
    Proposal title: GaiaNIR Combining optical and Near-Infra-Red (NIR) capabilities with Time-Delay-Integration (TDI) sensors for a future Gaia-like mission. PI: Dr. David Hobbs, Lund Observatory, Box 43, SE-221 00 Lund, Sweden. Email: [email protected]. Tel.: +46-46-22 21573 Core team members: The following minimum team is needed to initiate the project. D. Hobbs Lund Observatory, Sweden. A. Brown Leiden Observatory, Holland. A. Mora Aurora Technology B.V., Spain. C. Crowley HE Space Operations B.V., Spain. N. Hambly University of Edinburgh, UK. J. Portell Institut de Ciències del Cosmos, ICCUB-IEEC, Spain. C. Fabricius Institut de Ciències del Cosmos, ICCUB-IEEC, Spain. M. Davidson University of Edinburgh, UK. Proposal writers: See Appendix A. Other supporting scientists: See Appendix B and Appendix C. Senior science advisors: E. Høg Copenhagen University (Retired), Denmark. L. Lindegren Lund Observatory, Sweden. C. Jordi Institut de Ciències del Cosmos, ICCUB-IEEC, Spain. S. Klioner Lohrmann Observatory, Germany. F. Mignard Observatoire de la Côte d’Azur, France. arXiv:1609.07325v2 [astro-ph.IM] 22 May 2020 Fig. 1: Left is an IR image from the Two Micron All-Sky Survey (image G. Kopan, R. Hurt) while on the right an artist’s concept of the Gaia mission superimposed on an optical image, (Image ESA). Images not to scale. 1 1. Executive summary ESA recently called for new “Science Ideas” to be investigated in terms of feasibility and technological developments – for tech- nologies not yet sufficiently mature. These ideas may in the future become candidates for M or L class missions within the ESA Science Program.
    [Show full text]
  • Astronomy & Astrophysics a Hipparcos Study of the Hyades
    A&A 367, 111–147 (2001) Astronomy DOI: 10.1051/0004-6361:20000410 & c ESO 2001 Astrophysics A Hipparcos study of the Hyades open cluster Improved colour-absolute magnitude and Hertzsprung{Russell diagrams J. H. J. de Bruijne, R. Hoogerwerf, and P. T. de Zeeuw Sterrewacht Leiden, Postbus 9513, 2300 RA Leiden, The Netherlands Received 13 June 2000 / Accepted 24 November 2000 Abstract. Hipparcos parallaxes fix distances to individual stars in the Hyades cluster with an accuracy of ∼6per- cent. We use the Hipparcos proper motions, which have a larger relative precision than the trigonometric paral- laxes, to derive ∼3 times more precise distance estimates, by assuming that all members share the same space motion. An investigation of the available kinematic data confirms that the Hyades velocity field does not contain significant structure in the form of rotation and/or shear, but is fully consistent with a common space motion plus a (one-dimensional) internal velocity dispersion of ∼0.30 km s−1. The improved parallaxes as a set are statistically consistent with the Hipparcos parallaxes. The maximum expected systematic error in the proper motion-based parallaxes for stars in the outer regions of the cluster (i.e., beyond ∼2 tidal radii ∼20 pc) is ∼<0.30 mas. The new parallaxes confirm that the Hipparcos measurements are correlated on small angular scales, consistent with the limits specified in the Hipparcos Catalogue, though with significantly smaller “amplitudes” than claimed by Narayanan & Gould. We use the Tycho–2 long time-baseline astrometric catalogue to derive a set of independent proper motion-based parallaxes for the Hipparcos members.
    [Show full text]
  • Michael Perryman
    Michael Perryman Cavendish Laboratory, Cambridge (1977−79) European Space Agency, NL (1980−2009) (Hipparcos 1981−1997; Gaia 1995−2009) [Leiden University, NL,1993−2009] Max-Planck Institute for Astronomy & Heidelberg University (2010) Visiting Professor: University of Bristol (2011−12) University College Dublin (2012−13) Lecture program 1. Space Astrometry 1/3: History, rationale, and Hipparcos 2. Space Astrometry 2/3: Hipparcos science results (Tue 5 Nov) 3. Space Astrometry 3/3: Gaia (Thu 7 Nov) 4. Exoplanets: prospects for Gaia (Thu 14 Nov) 5. Some aspects of optical photon detection (Tue 19 Nov) M83 (David Malin) Hipparcos Text Our Sun Gaia Parallax measurement principle… Problematic from Earth: Sun (1) obtaining absolute parallaxes from relative measurements Earth (2) complicated by atmosphere [+ thermal/gravitational flexure] (3) no all-sky visibility Some history: the first 2000 years • 200 BC (ancient Greeks): • size and distance of Sun and Moon; motion of the planets • 900–1200: developing Islamic culture • 1500–1700: resurgence of scientific enquiry: • Earth moves around the Sun (Copernicus), better observations (Tycho) • motion of the planets (Kepler); laws of gravity and motion (Newton) • navigation at sea; understanding the Earth’s motion through space • 1718: Edmond Halley • first to measure the movement of the stars through space • 1725: James Bradley measured stellar aberration • Earth’s motion; finite speed of light; immensity of stellar distances • 1783: Herschel inferred Sun’s motion through space • 1838–39: Bessell/Henderson/Struve
    [Show full text]
  • Photometry of Be Stars in the Vicinity of COROT Primary Targets for Asteroseismology
    Comm. in Asteroseismology Vol. 143, 2003 Photometry of Be stars in the vicinity of COROT primary targets for asteroseismology J. Guti´errez-Soto1, J. Fabregat1, J. Suso2, A.M. Hubert3, M. Floquet3 and R. Garrido4 1 Observatori Astron`omic, Universitat de Val`encia 2 Instituto Ciencia de los Materiales, Universitat de Val`encia 3GEPI, Observatoire de Paris-Meudon 4Instituto de Astrof´ısica de Andaluc´ıa Abstract We present differential photometry of Be stars close to potential COROT pri- mary targets for asteroseismology. Several stars are found to be short pe- riod variables. We propose them to be considered as secondary targets in the COROT asteroseismology fields. Introduction The observation of classical Be stars by COROT will provide important keys to understand the physics of these objects and the nature of the Be phenomenon. In particular, the detection of photospheric multiperiodicity will confirm the presence of non radial pulsations (nrp) as the origin of the short term variability. COROT observations will allow the study of the beat phenomenon of nrp modes and its relation with recurrent outbursts and the building of the circumstellar disc. Our group is proposing the observation of Be stars as secondary targets for the asteroseismology fields. A sample of stars in the vicinity of the main target candidates is under study for this purpose. Hubert et al. (2001, 2003) presented the selected objects and performed a study of their short term variability using Hipparcos photometric data. We have obtained new ground based photometry with a more suitable time sampling to further characterize their variability. 2 Photometry of Be stars in the vicinity of COROT primary targets for asteroseismology Observations and data analysis Observations were done at the 0.9 m telescope of the Observatorio de Sierra Nevada (Granada, Spain).
    [Show full text]
  • Long-Period Variables in the Corot Fields⋆
    A&A 530, A35 (2011) Astronomy DOI: 10.1051/0004-6361/201116801 & c ESO 2011 Astrophysics Long-period variables in the CoRoT fields T. Lebzelter Department of Astronomy, University of Vienna, Tuerkenschanzstrasse 17, 1180 Vienna, Austria e-mail: [email protected] Received 28 February 2011 / Accepted 31 March 2011 ABSTRACT Aims. We searched the first set of data released by the CoRoT mission for red stars showing long-period variability (LPV). These stars are likely highly evolved stars on the upper giant branch. The high time resolution of the CoRoT data allows us to study the light curves of these variables in unprecedented detail. Methods. Light curves of the reddest stars were extracted from the CoRoT public archive. The search for LPV was done by visual inspection. Instrumental artefacts were removed, and the final light curves were inspected for signs of variability on time scales of hours to a few days. Such abrupt and irregular light curve changes have been reported in the literature to occur in these stars, but their origin is not yet understood. Results. We detected 52 LPV candidates in four CoRoT fields, most of them previously unknown. No signs of any short-time light changes on time scales between 20 min and a few days and an amplitude exceeding a few mmag could be detected. We conclude that if these short-time variations are physical reality, they must be quite rare events, and we derive a 95% confidence upper limit of 0.15 events per star per year. Any deviations from a perfectly smooth long-time variation are occurring on time scales longer than approximately 10 days.
    [Show full text]
  • Astrometry with the Hubble Space Telescope: Trigonometric Parallaxes of Selected Hyads∗
    The Astronomical Journal, 141:172 (12pp), 2011 May doi:10.1088/0004-6256/141/5/172 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. ASTROMETRY WITH THE HUBBLE SPACE TELESCOPE: TRIGONOMETRIC PARALLAXES OF SELECTED HYADS∗ Barbara E. McArthur1, G. Fritz Benedict1, Thomas E. Harrison2, and William van Altena3 1 McDonald Observatory, University of Texas, Austin, TX 78712, USA 2 Department of Astronomy, New Mexico State University, Las Cruces, NM 88003, USA 3 Department of Astronomy, Yale University, New Haven, CT 06520, USA Received 2011 February 7; accepted 2011 March 7; published 2011 April 7 ABSTRACT We present absolute parallaxes and proper motions for seven members of the Hyades open cluster, pre-selected to lie in the core of the cluster. Our data come from archival astrometric data from fine guidance sensor (FGS) 3 and newer data for three Hyads from FGS 1r, both white-light interferometers on the Hubble Space Telescope (HST). We obtain member parallaxes from six individual FGS fields and use the field containing van Altena 622 and van Altena 627 (= HIP 21138) as an example. Proper motions, spectral classifications, and VJHK photometry of the stars comprising the astrometric reference frames provide spectrophotometric estimates of reference star absolute parallaxes. Introducing these into our model as observations with error, we determine absolute parallaxes for each Hyad. The parallax of vA 627 is significantly improved by including a perturbation orbit for this previously known spectroscopic binary, now an astrometric binary. Compared to our original (1997) determinations, a combination of new data, updated calibration, and improved analysis lowered the individual parallax errors by an average factor of 4.5.
    [Show full text]
  • Microarcsecond Astrometry: Science Highlights from Gaia Arxiv
    Microarcsecond Astrometry: Science Highlights from Gaia Anthony G.A. Brown Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands; email: [email protected] Xxxx. Xxx. Xxx. Xxx. YYYY. AA:1{61 Keywords https://doi.org/10.1146/((please add astrometry, space vehicles: Gaia, catalogs, surveys article doi)) Copyright © YYYY by Annual Reviews. Abstract All rights reserved Access to microarcsecond astrometry is now routine in the radio, in- frared, and optical domains. In particular the publication of the sec- ond data release from the Gaia mission made it possible for every as- tronomer to work with easily accessible, high-precision astrometry for 1:7 billion sources to 21st magnitude over the full sky. • Gaia provides splendid astrometry but at the limits of the data small systematic errors are present. A good understanding of the Hipparcos/Gaia astrometry concept, and of the data collection and processing, provides insights into the origins of the systematic errors and how to mitigate their effects. • A selected set of results from Gaia highlight the breadth of excit- ing science and unexpected results, from the solar system to the distant universe, to creative uses of the data. • Gaia DR2 provides for the first time a dense sampling of Galactic phase space with high precision astrometry, photometry, and ra- dial velocities, allowing to uncover subtle features in phase space and the observational HR diagram. • In the coming decade, we can look forward to more accurate and richer Gaia data releases, and new photometric and spectroscopic surveys coming online that will provide essential complementary arXiv:2102.11712v2 [astro-ph.IM] 16 Sep 2021 data.
    [Show full text]
  • ASTRONOMY and ASTROPHYSICS Photometric and Spectroscopic Studies of Cool Stars Discovered in EXOSAT X-Ray Images?,?? IV
    Astron. Astrophys. 364, 205–216 (2000) ASTRONOMY AND ASTROPHYSICS Photometric and spectroscopic studies of cool stars discovered in EXOSAT X-ray images?;?? IV. The northern hemisphere sample G. Cutispoto1, L. Pastori2, A. Guerrero2, G. Tagliaferri2, S. Messina1, M. Rodono`1;3, and J.R. de Medeiros4 1 Catania Astrophysical Observatory, via S. Sofia 78, 95125 Catania, Italy 2 Brera Astronomical Observatory, Via Bianchi 46, 22055 Merate, Italy 3 Catania University, Department of Physics and Astronomy, via S. Sofia 78, 95125 Catania, Italy 4 University Federal of Rio Grande do Norte, Department of Physics, 59072-970 Natal, R.N., Brazil Received 20 July 2000 / Accepted 2 October 2000 Abstract. We present high-precision photometry, high- and et al. 1991; Pounds et al. 1993; Pye et al. 1995; Malina et al. medium-resolution spectroscopy for a sample of 32 stars likely 1994; Bowyer et al. 1996). Optical follow-up studies have shown to be the optical counterparts of X-ray sources serendipitously that these samples are strongly dominated by active stars, pre- detected by the EXOSATsatellite. Using also recent results from main sequence and other very young stars (see, among others, the Hipparcos satellite, we infer spectral types, compute X-ray Fleming et al. 1988,1989b; Favata et al. 1993,1995; Jeffries luminosities and Li abundances and investigate the single or bi- et al. 1995; Neuhauser¨ et al. 1997; Cutispoto et al. 1999). In nary nature of the sample stars. We found eleven new variable order to determine the physical nature of the stellar serendipi- stars, whose photometric periods fall in the 1.2-27.5 day range, tous X-ray sources detected by EXOSAT, our group embarked for most of which the optical variability is consistent with the into an extensive optical program which includes multicolor presence of photospheric cool spots.
    [Show full text]
  • The XMM 20 Year Reunion – Some Random Thoughts for the Panel Discussion
    The XMM 20 year reunion – some random thoughts for the panel discussion. Brian Taylor (formerly Head of Astrophysics Division, Space Science Department, ESTEC) The longevity of space missions truly amazing compared with early space missions: - first ESRO missions: typical design life one year and budget to operate for two, - now, technological advances, miniaturization, reduction of power demand etc., - HEOS 1, ESRO’s 3rd satellite (I was project scientist), launched in 1968, to study solar wind and cosmic rays, into 4.5 day period orbit, - 12bps VHF downlink, instruments either on or off ! Now we have XMM operating for 20 years, maybe 30. Always a financial crisis: HEOS 1 - ESRO science budget cut to make room for applications satellites, advent of ESA 1975, - missions always quite different, no commonality in spacecraft design, - expanding space science community, - need in mid-70s to join with NASA e.g. IUE and ISEE missions for a viable programme, - delay in the launching of EXOSAT conceived in early 70s, launched in 1983, - however unique missions also approved and undertaken e.g. Hipparcos and ISO. XMM Reunion 2019, Brian Taylor 1 Turning to Early X-ray Astrophysics: - in ESRO/ESA, X-ray astronomy initially lost out to gamma-ray astronomy (COS-B), - ‘resurrection’ in the form of HELOS, using lunar occultation to determine the precise location (~arcsecs) of X-ray sources, - HELOS morphed into EXOSAT with the advent of NASA’s Einstein. EXOSAT the first ESA satellite with: ~arcsec pointing and stability, - star trackers, - on-board computer, - pioneering replicated X-ray optics > adopted for XMM, - HEO for long uninterrupted observations.
    [Show full text]
  • Spacelabspacelab
    SpacelabSpacelab Achievements: principal scientific manned module for US Space Shuttle; major contributions to space sciences research and applications; first European manned space project; 22 missions Launch dates: see table Launch vehicle/site: US Space Shuttle, Kennedy Space Center, Florida Launch mass: typically 10 t (Spacelab-1 totalled 8145 kg Pressure Module and 3386 kg Pallet; including experiments totalling 1392 kg) Orbits: typically 300 km altitude, inclinations 28-57° Principal contractors: VFW-Fokker/ERNO (later MBB/ERNO; prime), Aeritalia (PM structure, Igloo, thermal control), Matra (command/data management), Dornier (IPS, ECLSS), British Aerospace (Pallet) Spacelab was an integral element of NASA’s Space Shuttle programme and provided ESA/ESRO with a unique opportunity for developing a manned space capability. The 22 missions made outstanding contributions to astronomy, life sciences, atmospheric physics, Earth observation and materials science under microgravity – advances that stemmed from this crucial European contribution. Spacelab essentially comprised two types of payload carrier: a pressurised manned laboratory module and unpressurised external pallets. Its flexibility allowed it to accommodate both multi- disciplinary experiments and complements devoted to a single scientific or applications theme. The Pressure Module (PM) hosted the experiments equipment, data processing and electrical power equipment, an environmental control system and crew control stations. The crew of up to six researchers relied on the Shuttle Orbiter for living quarters, communications and data transmissions. Europe was invited in 1969 to participate in the post-Apollo Spacelab was an programme, ultimately deciding at integral part of the the Ministerial Meeting of the Space Transportation European Space Conference in System. Shown is the Spacelab-1 Brussels on 20 December 1972 to configuration, flown in entrust ESRO with developing a 1983.
    [Show full text]