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Mathématiques Et Espace
Atelier disciplinaire AD 5 Mathématiques et Espace Anne-Cécile DHERS, Education Nationale (mathématiques) Peggy THILLET, Education Nationale (mathématiques) Yann BARSAMIAN, Education Nationale (mathématiques) Olivier BONNETON, Sciences - U (mathématiques) Cahier d'activités Activité 1 : L'HORIZON TERRESTRE ET SPATIAL Activité 2 : DENOMBREMENT D'ETOILES DANS LE CIEL ET L'UNIVERS Activité 3 : D'HIPPARCOS A BENFORD Activité 4 : OBSERVATION STATISTIQUE DES CRATERES LUNAIRES Activité 5 : DIAMETRE DES CRATERES D'IMPACT Activité 6 : LOI DE TITIUS-BODE Activité 7 : MODELISER UNE CONSTELLATION EN 3D Crédits photo : NASA / CNES L'HORIZON TERRESTRE ET SPATIAL (3 ème / 2 nde ) __________________________________________________ OBJECTIF : Détermination de la ligne d'horizon à une altitude donnée. COMPETENCES : ● Utilisation du théorème de Pythagore ● Utilisation de Google Earth pour évaluer des distances à vol d'oiseau ● Recherche personnelle de données REALISATION : Il s'agit ici de mettre en application le théorème de Pythagore mais avec une vision terrestre dans un premier temps suite à un questionnement de l'élève puis dans un second temps de réutiliser la même démarche dans le cadre spatial de la visibilité d'un satellite. Fiche élève ____________________________________________________________________________ 1. Victor Hugo a écrit dans Les Châtiments : "Les horizons aux horizons succèdent […] : on avance toujours, on n’arrive jamais ". Face à la mer, vous voyez l'horizon à perte de vue. Mais "est-ce loin, l'horizon ?". D'après toi, jusqu'à quelle distance peux-tu voir si le temps est clair ? Réponse 1 : " Sans instrument, je peux voir jusqu'à .................. km " Réponse 2 : " Avec une paire de jumelles, je peux voir jusqu'à ............... km " 2. Nous allons maintenant calculer à l'aide du théorème de Pythagore la ligne d'horizon pour une hauteur H donnée. -
The Skyscraper 2009 04.Indd
A Better Galaxy Guide: Early Spring M67: One of the most ancient open clusters known and Craig Cortis is a great novelty in this regard. Located 1.7° due W of mag NGC 2419: 3.25° SE of mag 6.2 66 Aurigae. Hard to find 4.3 Alpha Cancri. and see; at E end of short row of two mag 7.5 stars. Highly NGC 2775: Located 3.7° ENE of mag 3.1 Zeta Hydrae. significant and worth the effort —may be approximately (Look for “Head of Hydra” first.) 300,000 light years distant and qualify as an extragalactic NGC 2903: Easily found at 1.5° due S of mag 4.3 Lambda cluster. Named the Intergalactic Wanderer. Leonis. NGC 2683: Marks NW “crook” of coathanger-type triangle M95: One of three bright galaxies forming a compact with easy double star mag 4.2 Iota Cancri (which is SSW by triangle, along with M96 and M105. All three can be seen 4.8°) and mag 3.1 Alpha Lyncis (at 6° to the ENE). together in a low power, wide field view. M105 is at the NE tip of triangle, midway between stars 52 and 53 Leonis, mag Object Type R.A. Dec. Mag. Size 5.5 and 5.3 respectively —M95 is at W tip. Lynx NGC 3521: Located 0.5° due E of mag 6.0 62 Leonis. M65: One of a pair of bright galaxies that can be seen in NGC 2419 GC 07h 38.1m +38° 53’ 10.3 4.2’ a wide field view along with M66, which lies just E. -
Eating Planets for Lunch and Dinner: Signatures of Planet Consumption by Evolving Stars
Draft version September 13, 2019 Typeset using LATEX twocolumn style in AASTeX62 Eating Planets for Lunch and Dinner: Signatures of Planet Consumption by Evolving Stars Alexander P. Stephan,1, 2 Smadar Naoz,1, 2 B. Scott Gaudi,3 and Jesus M. Salas1, 2 1Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA 2Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles, Los Angeles, CA 90095, USA 3Department of Astronomy, The Ohio State University, Columbus, OH 43210, USA (Received XXX; Revised YYY; Accepted ZZZ) Submitted to ApJ ABSTRACT Exoplanets have been observed around stars at all stages of stellar evolution, in many cases orbiting in configurations that will eventually lead to the planets being engulfed or consumed by their host stars, such as Hot Jupiters or ultra-short period planets. Furthermore, objects such as polluted white dwarfs provide strong evidence that the consumption of planets by stars is a common phenomenon. This consumption causes several significant changes in the stellar properties, such as changes to the stellar spin, luminosity, chemical composition, or mass loss processes. Here, we explore this wide variety of effects for a comprehensive range of stellar and planetary masses and stages of stellar evolution, from the main sequence over red giants to the white dwarfs. We determine that planet consumption can cause transient luminosity features that last on the order of centuries to millennia, and that the post-consumption stellar spins can often reach break-up speeds. Furthermore, stellar moss loss can be caused by this spin-up, as well as through surface grazing interactions, leading to to the formation of unusual planetary nebula shapes or collimated stellar gas ejections. -
The Brightest Stars Seite 1 Von 9
The Brightest Stars Seite 1 von 9 The Brightest Stars This is a list of the 300 brightest stars made using data from the Hipparcos catalogue. The stellar distances are only fairly accurate for stars well within 1000 light years. 1 2 3 4 5 6 7 8 9 10 11 12 13 No. Star Names Equatorial Galactic Spectral Vis Abs Prllx Err Dist Coordinates Coordinates Type Mag Mag ly RA Dec l° b° 1. Alpha Canis Majoris Sirius 06 45 -16.7 227.2 -8.9 A1V -1.44 1.45 379.21 1.58 9 2. Alpha Carinae Canopus 06 24 -52.7 261.2 -25.3 F0Ib -0.62 -5.53 10.43 0.53 310 3. Alpha Centauri Rigil Kentaurus 14 40 -60.8 315.8 -0.7 G2V+K1V -0.27 4.08 742.12 1.40 4 4. Alpha Boötis Arcturus 14 16 +19.2 15.2 +69.0 K2III -0.05 -0.31 88.85 0.74 37 5. Alpha Lyrae Vega 18 37 +38.8 67.5 +19.2 A0V 0.03 0.58 128.93 0.55 25 6. Alpha Aurigae Capella 05 17 +46.0 162.6 +4.6 G5III+G0III 0.08 -0.48 77.29 0.89 42 7. Beta Orionis Rigel 05 15 -8.2 209.3 -25.1 B8Ia 0.18 -6.69 4.22 0.81 770 8. Alpha Canis Minoris Procyon 07 39 +5.2 213.7 +13.0 F5IV-V 0.40 2.68 285.93 0.88 11 9. Alpha Eridani Achernar 01 38 -57.2 290.7 -58.8 B3V 0.45 -2.77 22.68 0.57 144 10. -
Chapter 1 a Theoretical and Observational Overview of Brown
Chapter 1 A theoretical and observational overview of brown dwarfs Stars are large spheres of gas composed of 73 % of hydrogen in mass, 25 % of helium, and about 2 % of metals, elements with atomic number larger than two like oxygen, nitrogen, carbon or iron. The core temperature and pressure are high enough to convert hydrogen into helium by the proton-proton cycle of nuclear reaction yielding sufficient energy to prevent the star from gravitational collapse. The increased number of helium atoms yields a decrease of the central pressure and temperature. The inner region is thus compressed under the gravitational pressure which dominates the nuclear pressure. This increase in density generates higher temperatures, making nuclear reactions more efficient. The consequence of this feedback cycle is that a star such as the Sun spend most of its lifetime on the main-sequence. The most important parameter of a star is its mass because it determines its luminosity, ef- fective temperature, radius, and lifetime. The distribution of stars with mass, known as the Initial Mass Function (hereafter IMF), is therefore of prime importance to understand star formation pro- cesses, including the conversion of interstellar matter into stars and back again. A major issue regarding the IMF concerns its universality, i.e. whether the IMF is constant in time, place, and metallicity. When a solar-metallicity star reaches a mass below 0.072 M ¡ (Baraffe et al. 1998), the core temperature and pressure are too low to burn hydrogen stably. Objects below this mass were originally termed “black dwarfs” because the low-luminosity would hamper their detection (Ku- mar 1963). -
Searching for Gas Giant Planets on Solar System Scales – a NACO/APP L-Band Survey of A- and F-Type Main-Sequence Stars
MNRAS 453, 2533–2539 (2015) doi:10.1093/mnras/stv1779 Searching for gas giant planets on Solar system scales – a NACO/APP L-band survey of A- and F-type main-sequence stars T. Meshkat,1‹ M. A. Kenworthy,1 M. Reggiani,2 S. P. Quanz,2 E. E. Mamajek3 andM.R.Meyer2 1Leiden Observatory, PO Box 9513, Niels Bohrweg 2, NL-2300 RA Leiden, the Netherlands 2Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich, Switzerland 3Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, USA Accepted 2015 August 3. Received 2015 July 2; in original form 2015 March 17 Downloaded from ABSTRACT We report the results of a direct imaging survey of A- and F-type main-sequence stars search- ing for giant planets. A/F stars are often the targets of surveys, as they are thought to have more massive giant planets relative to solar-type stars. However, most imaging is only sen- http://mnras.oxfordjournals.org/ sitive to orbital separations >30 au, where it has been demonstrated that giant planets are rare. In this survey, we take advantage of the high-contrast capabilities of the Apodizing Phase Plate coronagraph on NACO at the Very Large Telescope. Combined with optimized principal component analysis post-processing, we are sensitive to planetary-mass companions (2–12 MJup) at Solar system scales (≤30 au). We obtained data on 13 stars in the L band and detected one new companion as part of this survey: an M6.0 ± 0.5 dwarf companion around HD 984. -
Fang Family San Francisco Examiner Photograph Archive Negative Files, Circa 1930-2000, Circa 1930-2000
http://oac.cdlib.org/findaid/ark:/13030/hb6t1nb85b No online items Finding Aid to the Fang family San Francisco examiner photograph archive negative files, circa 1930-2000, circa 1930-2000 Bancroft Library staff The Bancroft Library University of California, Berkeley Berkeley, CA 94720-6000 Phone: (510) 642-6481 Fax: (510) 642-7589 Email: [email protected] URL: http://bancroft.berkeley.edu/ © 2010 The Regents of the University of California. All rights reserved. Finding Aid to the Fang family San BANC PIC 2006.029--NEG 1 Francisco examiner photograph archive negative files, circa 1930-... Finding Aid to the Fang family San Francisco examiner photograph archive negative files, circa 1930-2000, circa 1930-2000 Collection number: BANC PIC 2006.029--NEG The Bancroft Library University of California, Berkeley Berkeley, CA 94720-6000 Phone: (510) 642-6481 Fax: (510) 642-7589 Email: [email protected] URL: http://bancroft.berkeley.edu/ Finding Aid Author(s): Bancroft Library staff Finding Aid Encoded By: GenX © 2011 The Regents of the University of California. All rights reserved. Collection Summary Collection Title: Fang family San Francisco examiner photograph archive negative files Date (inclusive): circa 1930-2000 Collection Number: BANC PIC 2006.029--NEG Creator: San Francisco Examiner (Firm) Extent: 3,200 boxes (ca. 3,600,000 photographic negatives); safety film, nitrate film, and glass : various film sizes, chiefly 4 x 5 in. and 35mm. Repository: The Bancroft Library. University of California, Berkeley Berkeley, CA 94720-6000 Phone: (510) 642-6481 Fax: (510) 642-7589 Email: [email protected] URL: http://bancroft.berkeley.edu/ Abstract: Local news photographs taken by staff of the Examiner, a major San Francisco daily newspaper. -
Search for Associations Containing Young Stars (SACY). V. Is
Astronomy & Astrophysics manuscript no. sacy˙1˙accepted˙arxiv˙2 c ESO 2018 October 2, 2018 Search for associations containing young stars (SACY) V. Is multiplicity universal? Tight multiple systems?;??;??? P. Elliott1;2, A. Bayo1;3;4, C. H. F. Melo1, C. A. O. Torres5, M. Sterzik1, and G. R. Quast5 1 European Southern Observatory, Alonso de Cordova 3107, Vitacura Casilla 19001, Santiago 19, Chile e-mail: [email protected] 2 School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL 3 Max Planck Institut fur¨ Astronomie, Konigstuhl¨ 17, 69117, Heidelberg, Germany 4 Departamento de F´ısica y Astronom´ıa, Facultad de Ciencias, Universidad de Valpara´ıso, Av. Gran Bretana˜ 1111, 5030 Casilla, Valpara´ıso, Chile 5 Laboratorio´ Nacional de Astrof´ısica/ MCT, Rua Estados Unidos 154, 37504-364 Itajuba´ (MG), Brazil Received 21 March 2014 / Accepted 5 June 2014 ABSTRACT Context. Dynamically undisrupted, young populations of stars are crucial in studying the role of multiplicity in relation to star formation. Loose nearby associations provide us with a great sample of close (<150 pc) pre-main sequence (PMS) stars across the very important age range (≈5-70 Myr) to conduct such research. Aims. We characterize the short period multiplicity fraction of the search for associations containing young stars (SACY) sample, accounting for any identifiable bias in our techniques and present the role of multiplicity fractions of the SACY sample in the context of star formation. Methods. Using the cross-correlation technique we identified double-lined and triple-lined spectroscopic systems (SB2/SB3s), in addition to this we computed radial velocity (RV) values for our subsample of SACY targets using several epochs of fiber-fed extended range optical spectrograph (FEROS) and ultraviolet and visual echelle spectrograph (UVES) data. -
Search for Associations Containing Young Stars (SACY) VII
A&A 590, A13 (2016) Astronomy DOI: 10.1051/0004-6361/201628253 & c ESO 2016 Astrophysics Search for associations containing young stars (SACY) VII. New stellar and substellar candidate members in the young associations?,?? P. Elliott1; 2, A. Bayo3, C. H. F. Melo1, C. A. O. Torres4, M. F. Sterzik5, G. R. Quast4, D. Montes6, and R. Brahm7; 8 1 European Southern Observatory, Alonso de Cordova 3107, Vitacura Casilla 19001, Santiago 19, Chile e-mail: [email protected] 2 School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL 3 Departamento de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Av. Gran Bretaña 1111, 5030 Casilla, Valparaíso, Chile 4 Laboratório Nacional de Astrofísica/ MCT, Rua Estados Unidos 154, 37504-364 Itajubá (MG), Brazil 5 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany 6 Departamento de Astrofísica y Ciencias de la Atmósfera, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain 7 Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile 8 Millennium Institute of Astrophysics, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile Received 4 February 2016 / Accepted 7 March 2016 ABSTRACT Context. The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<200 pc) and age (≈5−150 Myr). However, many previous works have been limited to identifying the brighter, more active members (≈1 M ) owing to photometric survey sensitivities limiting the detections of lower mass objects. -
Homogeneous Photospheric Parameters and C Abundances in G and K Nearby Stars with and Without Planets , ,
A&A 526, A71 (2011) Astronomy DOI: 10.1051/0004-6361/201015907 & c ESO 2010 Astrophysics Homogeneous photospheric parameters and C abundances in G and K nearby stars with and without planets,, R. Da Silva1,A.C.Milone1, and B. E. Reddy2 1 Astrophysics Division, Instituto Nacional de Pesquisas Espaciais, 12227-010 São José dos Campos, Brazil e-mail: [email protected] 2 Indian Institute of Astrophysics, 560034 Bengaluru, India Received 11 October 2010 / Accepted 22 November 2010 ABSTRACT Aims. We present a determination of photospheric parameters and carbon abundances for a sample of 172 G and K dwarf, subgiant, and giant stars with and without detected planets in the solar neighbourhood. The analysis was based on high signal-to-noise ratio and high resolution spectra observed with the ELODIE spectrograph (Haute Provence Observatory, France) and for which the observational data were publicly available. We intend to contribute precise and homogeneous C abundances in studies that compare the behaviour of light elements in stars with and without planets. This will bring new arguments to the discussion of possible anomalies that have been suggested and will contribute to a better understanding of different planetary formation process. Methods. The photospheric parameters were computed through the excitation potential, equivalent widths, and ionisation equilibrium of iron lines selected in the spectra. Carbon abundances were derived from spectral synthesis applied to prominent molecular head bands of C2 Swan (λ5128 and λ5165) and to a C atomic line (λ5380.3). Careful attention was drawn to carry out this homogeneous procedure and to compute the internal uncertainties. -
Stellar Parameters and Chemical Abundances of 223 Evolved Stars with and Without Planets ,
A&A 574, A50 (2015) Astronomy DOI: 10.1051/0004-6361/201424474 & c ESO 2015 Astrophysics Stellar parameters and chemical abundances of 223 evolved stars with and without planets, E. Jofré1,4,,R.Petrucci2,4,C.Saffe3,4,L.Saker1, E. Artur de la Villarmois1,C.Chavero1,4, M. Gómez1,4, and P. J. D. Mauas2,4 1 Observatorio Astronómico de Córdoba (OAC), Laprida 854, X5000BGR Córdoba, Argentina e-mail: [email protected] 2 Instituto de Astronomía y Física del Espacio (IAFE), CC.67, suc. 28, 1428 Buenos Aires, Argentina 3 Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE), CC.467, 5400 San Juan, Argentina 4 Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina Received 25 June 2014 / Accepted 14 October 2014 ABSTRACT Aims. We present fundamental stellar parameters, chemical abundances, and rotational velocities for a sample of 86 evolved stars with planets (56 giants; 30 subgiants), and for a control sample of 137 stars (101 giants; 36 subgiants) without planets. The analysis was based on both high signal-to-noise and resolution echelle spectra. The main goals of this work are i) to investigate chemical differences between evolved stars that host planets and those of the control sample without planets; ii) to explore potential differences between the properties of the planets around giants and subgiants; and iii) to search for possible correlations between these properties and the chemical abundances of their host stars. Implications for the scenarios of planet formation and evolution are also discussed. Methods. The fundamental stellar parameters (Teff,logg,[Fe/H], ξt) were computed homogeneously using the FUNDPAR code. -
Financial Information Act Return for the Year Ended March 31, 2020
BRITISH COLUMBIA HYDRO AND POWER AUTHORITY Financial Information Act Return for the Year Ended March 31, 2020 Published in accordance with the Financial Information Act, Revised Statutes of British Columbia 1996, Chapter 140, as amended. 1 FINANCIAL INFORMATION ACT RETURN FOR THE YEAR ENDED MARCH 31, 2020 TABLE OF CONTENTS Statement of Financial Information Approval 3 Audited Consolidated Financial Statements Fiscal 2020 4 British Columbia Hydro and Power Authority and its subsidiary Powerex Corp. Schedule of Remuneration and Expenses – Board of Directors 73 British Columbia Hydro and Power Authority Schedule of Debts 75 Schedule of Guarantee and Indemnity Agreements 76 Schedule of Remuneration and Expenses 77 Schedule of Payments to Suppliers for Goods and Services 154 Statement of Grants and Contributions 191 Powerex Corp. Schedule of Remuneration and Expenses 192 Schedule of Payments to Suppliers for Goods and Services 196 Powertech Labs Inc. Schedule of Remuneration and Expenses 200 Schedule of Payments to Suppliers for Goods and Services 204 2 BRITISH COLUMBA HYDRO AND POWER AUTHORITY STATEMENT OF FINANCIAL INFORMATION APPROVAL The undersigned represents the Board of Directors of the British Columbia Hydro and Power Authority and approves the information contained in the Statement and Schedules of Financial Information prepared in accordance with the Financial Information Act. Kenneth G. Peterson Chair of the Board 3 British Columbia Hydro and Power Authority Management Report The consolidated financial statements of British Columbia Hydro and Power Authority (BC Hydro) are the responsibility of management and have been prepared in accordance with International Financial Reporting Standards. The preparation of financial statements necessarily involves the use of estimates which have been made using careful judgment.