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The Richard B. Kershner Space Integration and Test Facility
ALVIN G. BUSH, WILLIAM E. FRAIN, and ALBERT C. REYMANN THE RICHARD B. KERSHNER SPACE INTEGRATION AND TEST FACILITY This article describes the functional characteristics and capabilities of the APL Space Integration and Test Facility. Its design was begun in late 1981, and the building was dedicated on October 11, 1983. INTRODUCTION The Richard B. Kershner Space Integration and Test Facility (Fig. 1) provides laboratory and office space to support the assembly and testing of spacecraft and spacecraft-borne instruments. Environmental test fa cilities within its 79,000 square feet simulate the rigors of launch and of operations in the vacuum conditions of space. The building contains assembly and test rooms that are clean enough so that precision optical equipment will not be contaminated; laboratories for the development of components for attitude control systems, power system electronics, batteries, and so lar arrays; reliability and quality assurance laborato Figure 1-The Richard B. Kershner building contains offices, ries for the inspection of delicate electronics parts and laboratories, and clean rooms. It is the point of final assem for failure analysis; and office space for 155 engineers, bly and qualification of spacecraft and space instrumentation. technicians, draftsmen, and secretaries. At the core of the building's function are areas devoted to the assembly and testing of spacecraft and Space allocation and layout (Fig. 2) were determined spacecraft instruments. Five rooms, each with 1000 by the requirement for the flow, under one roof, of square feet of floor space, adjoin a staging area served individual parts from a certified clean stockroom by an overhead crane. -
Luminous Blue Variables
Review Luminous Blue Variables Kerstin Weis 1* and Dominik J. Bomans 1,2,3 1 Astronomical Institute, Faculty for Physics and Astronomy, Ruhr University Bochum, 44801 Bochum, Germany 2 Department Plasmas with Complex Interactions, Ruhr University Bochum, 44801 Bochum, Germany 3 Ruhr Astroparticle and Plasma Physics (RAPP) Center, 44801 Bochum, Germany Received: 29 October 2019; Accepted: 18 February 2020; Published: 29 February 2020 Abstract: Luminous Blue Variables are massive evolved stars, here we introduce this outstanding class of objects. Described are the specific characteristics, the evolutionary state and what they are connected to other phases and types of massive stars. Our current knowledge of LBVs is limited by the fact that in comparison to other stellar classes and phases only a few “true” LBVs are known. This results from the lack of a unique, fast and always reliable identification scheme for LBVs. It literally takes time to get a true classification of a LBV. In addition the short duration of the LBV phase makes it even harder to catch and identify a star as LBV. We summarize here what is known so far, give an overview of the LBV population and the list of LBV host galaxies. LBV are clearly an important and still not fully understood phase in the live of (very) massive stars, especially due to the large and time variable mass loss during the LBV phase. We like to emphasize again the problem how to clearly identify LBV and that there are more than just one type of LBVs: The giant eruption LBVs or h Car analogs and the S Dor cycle LBVs. -
Curriculum Vitae Thomas Matheson
Curriculum Vitae Thomas Matheson Address: NSF's National Optical-Infrared Astronomy Research Laboratory Community Science and Data Center 950 North Cherry Avenue Tucson, AZ 85719, USA Telephone: (520) 318{8517 Fax: (520) 318{8360 e-mail: [email protected] WWW: http://www.noao.edu/noao/staff/matheson/ Education: University of California, Berkeley, Berkeley, CA Department of Astronomy Ph.D. received June 2000 M.A. received June 1992 PhD Thesis Topic: The Spectral Characteristics of Stripped-Envelope Supernovae Thesis Advisor: Professor Alexei V. Filippenko Harvard University, Cambridge, MA Department of Astronomy & Astrophysics and Physics A.B. magna cum laude, received June 1989 Senior Thesis Topic: Transients in the Solar Transition Region Thesis Advisor: Professor Robert W. Noyes Employment: NSF's National Optical-Infrared Astronomy Research Laboratory (The Former National Optical Astronomy Observatory) Community Science and Data Center Head of Time-Domain Services 2017 { present Astronomer 2018 { present Associate Astronomer 2009 { 2018 (Tenure, 2011) Assistant Astronomer 2004 { 2009 Harvard-Smithsonian Center for Astrophysics Optical and Infrared Division Post-doctoral fellow 2000 { 2004 University of California, Berkeley Department of Astronomy Research Assistant 1991 { 2000 Harvard-Smithsonian Center for Astrophysics Solar and Stellar Physics Division Research Assistant 1989 { 1990 Thomas Matheson|Curriculum Vitae Teaching: Harvard University, Department of Astronomy, Teaching Assistant 2001, 2003 University of California, Berkeley, -
POSTERS SESSION I: Atmospheres of Massive Stars
Abstracts of Posters 25 POSTERS (Grouped by sessions in alphabetical order by first author) SESSION I: Atmospheres of Massive Stars I-1. Pulsational Seeding of Structure in a Line-Driven Stellar Wind Nurdan Anilmis & Stan Owocki, University of Delaware Massive stars often exhibit signatures of radial or non-radial pulsation, and in principal these can play a key role in seeding structure in their radiatively driven stellar wind. We have been carrying out time-dependent hydrodynamical simulations of such winds with time-variable surface brightness and lower boundary condi- tions that are intended to mimic the forms expected from stellar pulsation. We present sample results for a strong radial pulsation, using also an SEI (Sobolev with Exact Integration) line-transfer code to derive characteristic line-profile signatures of the resulting wind structure. Future work will compare these with observed signatures in a variety of specific stars known to be radial and non-radial pulsators. I-2. Wind and Photospheric Variability in Late-B Supergiants Matt Austin, University College London (UCL); Nevyana Markova, National Astronomical Observatory, Bulgaria; Raman Prinja, UCL There is currently a growing realisation that the time-variable properties of massive stars can have a funda- mental influence in the determination of key parameters. Specifically, the fact that the winds may be highly clumped and structured can lead to significant downward revision in the mass-loss rates of OB stars. While wind clumping is generally well studied in O-type stars, it is by contrast poorly understood in B stars. In this study we present the analysis of optical data of the B8 Iae star HD 199478. -
The Sitian Project
An Acad Bras Cienc (2021) 93(Suppl. 1): e20200628 DOI 10.1590/0001-3765202120200628 Anais da Academia Brasileira de Ciências | Annals of the Brazilian Academy of Sciences Printed ISSN 0001-3765 I Online ISSN 1678-2690 www.scielo.br/aabc | www.fb.com/aabcjournal PHYSICAL SCIENCES The SiTian Project JIFENG LIU, ROBERTO SORIA, XUE-FENG WU, HONG WU & ZHAOHUI SHANG Abstract: SiTian is an ambitious ground-based all-sky optical monitoring project, developed by the Chinese Academy of Sciences. The concept is an integrated network of dozens of 1-m-class telescopes deployed partly in China and partly at various other sites around the world. The main science goals are the detection, identification and monitoring of optical transients (such as gravitational wave events, fast radio bursts, supernovae) on the largely unknown timescales of less than 1 day; SiTian will also provide a treasure trove of data for studies of AGN, quasars, variable stars, planets, asteroids, and microlensing events. To achieve those goals, SiTian will scan at least 10,000 square deg of sky every 30 min, down to a detection limit of V ≈ 21 mag. The scans will produce simultaneous light-curves in 3 optical bands. In addition, SiTian will include at least three 4-m telescopes specifically allocated for follow-up spectroscopy of the most interesting targets. We plan to complete the installation of 72 telescopes by 2030 and start full scientific operations in 2032. Key words: surveys, telescopes, transients, relativistic processes. INTRODUCTION a 6.7-m filled aperture) with a 9.6 square deg field of view (Ivezić et al. -
The Thermal Limits to Life on Earth
International Journal of Astrobiology 13 (2): 141–154 (2014) doi:10.1017/S1473550413000438 © Cambridge University Press 2014. The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution licence http://creativecommons.org/licenses/by/3.0/. The thermal limits to life on Earth Andrew Clarke1,2 1British Antarctic Survey, Cambridge, UK 2School of Environmental Sciences, University of East Anglia, Norwich, UK e-mail: [email protected] Abstract: Living organisms on Earth are characterized by three necessary features: a set of internal instructions encoded in DNA (software), a suite of proteins and associated macromolecules providing a boundary and internal structure (hardware), and a flux of energy. In addition, they replicate themselves through reproduction, a process that renders evolutionary change inevitable in a resource-limited world. Temperature has a profound effect on all of these features, and yet life is sufficiently adaptable to be found almost everywhere water is liquid. The thermal limits to survival are well documented for many types of organisms, but the thermal limits to completion of the life cycle are much more difficult to establish, especially for organisms that inhabit thermally variable environments. Current data suggest that the thermal limits to completion of the life cycle differ between the three major domains of life, bacteria, archaea and eukaryotes. At the very highest temperatures only archaea are found with the current high-temperature limit for growth being 122 °C. Bacteria can grow up to 100 °C, but no eukaryote appears to be able to complete its life cycle above *60 °C and most not above 40 °C. -
The Thermal Limits to Life on Earth
International Journal of Astrobiology 13 (2): 141–154 (2014) doi:10.1017/S1473550413000438 © Cambridge University Press 2014. The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution licence http://creativecommons.org/licenses/by/3.0/. The thermal limits to life on Earth Andrew Clarke1,2 1British Antarctic Survey, Cambridge, UK 2School of Environmental Sciences, University of East Anglia, Norwich, UK e-mail: [email protected] Abstract: Living organisms on Earth are characterized by three necessary features: a set of internal instructions encoded in DNA (software), a suite of proteins and associated macromolecules providing a boundary and internal structure (hardware), and a flux of energy. In addition, they replicate themselves through reproduction, a process that renders evolutionary change inevitable in a resource-limited world. Temperature has a profound effect on all of these features, and yet life is sufficiently adaptable to be found almost everywhere water is liquid. The thermal limits to survival are well documented for many types of organisms, but the thermal limits to completion of the life cycle are much more difficult to establish, especially for organisms that inhabit thermally variable environments. Current data suggest that the thermal limits to completion of the life cycle differ between the three major domains of life, bacteria, archaea and eukaryotes. At the very highest temperatures only archaea are found with the current high-temperature limit for growth being 122 °C. Bacteria can grow up to 100 °C, but no eukaryote appears to be able to complete its life cycle above *60 °C and most not above 40 °C. -
Lecture 17 Binary Evolution Type Ib and Ic Supernovae
Lecture 17 Binary Evolution Type Ib and Ic Supernovae Half or more of massive stars are found in binaries with such close separations that the stars will interact when one of them becomes a supergiant (Sana & Evans 2011; Sana et al. 2012). [Podsiadlowski says 30 – 50%, but in any case the fraction is large] 6 Ph. Podsiadlowski Classification of Roche-lobe overflow phases See class website 5 MO (Paczynski) carbon ignition P = 4300 d R/ RO. 1000 • Case A –the star is on 45 % M = 5 M the main sequence 1 O. P is the maximum period M / M = 2 1 2 Case C below which mass radius evolution exchange of the given • Case B – the star has type will occur finished H burning but 100 helium ignition not He burning P = 87 d The rough percentage of 5 MO stars that will interact during the 45 % • Case C – post-He core given stage is indicated burning Case B 10 P = 1.5 d Case A 10 % P = 0.65 d main sequence 7 0 5 10 (10 yr) Figure 1.1 The evolution of the radius of a 5 M⊙ star as a function of its lifetime to illustrate the ranges in radius and orbital period for the different cases of RLOF phases, as indicated, assuming a2.5 2 M⊙ companion. of stars and supernovae that probe the late evolutionary phases of a star (see § 1.4). Note also that quite massive stars (∼> 20 M⊙)tendtoexpandonlymoderatelyafter helium core burning, and hence, for massive stars, Case C masstransfertendsto be much less important than Case B mass transfer, where most oftheexpansion occurs. -
Challenging the Paradigms of Deep-Sea Ecology
Review Challenging the paradigms of deep-sea ecology 1,2* 3* 4* Roberto Danovaro , Paul V.R. Snelgrove , and Paul Tyler 1 Stazione Zoologica Anton Dohrn, Villa Comunale Napoli, 80121, Italy 2 Department of Life and Environmental Sciences (DiSVA), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy 3 Ocean Sciences Centre and Biology Department, Memorial University of Newfoundland, St. John’s, NL, A1C 5S7 Canada 4 Ocean and Earth Science, University of Southampton, NOC, Southampton SO14 3ZH, UK Deep-sea ecosystems represent Earth’s major ecological 1960s, first using semiquantitative anchor dredges and research frontier. Focusing on seafloor ecosystems, we epibenthic sledges [3], and subsequently using box corers demonstrate how new technologies underpin discover- [4]. The application of submersibles to scientific and bio- ies that challenge major ecological hypotheses and para- logical investigations enabled the discovery of hydrother- digms, illuminating new deep-sea geosphere–biosphere mal vents [5] and seeps [6], the first manipulative interactions. We now recognize greater habitat complex- experiments, the testing of ecological hypothesis in the ity, new ecological interactions and the importance of deep sea [7], the use of videos and still imagery to document ‘dark energy’, and chemosynthetic production in fuelling life in trenches, along with other advances aided by hybrid biodiversity. We also acknowledge functional hotspots remotely operated vehicles (ROVs), bottom crawlers, and that contradict a food-poor, metabolically inactive, and landers (Table 1). minor component of global carbon cycles. Symbioses Past exploration generated many paradigms, often draw- appear widespread, revealing novel adaptations. Popu- ing on information constrained by available measurements lations show complex spatial structure and evolutionary and technology [8,9], but the past decade has seen spectac- histories. -
Neutrinos from Supernovae John Beacom, the Ohio State University
Neutrinos From Supernovae John Beacom, The Ohio State University John Beacom, The Ohio State University IceCube Particle Astrophysics, Madison, May 2017 1 SN 1987A: Our Rosetta Stone IMB KamII Observation: Type II supernova Observation: The neutrino progenitors are massive stars precursor is very energetic Theory: Core collapse makes a proto-neutron star and neutrinos John Beacom, The Ohio State University IceCube Particle Astrophysics, Madison, May 2017 2 What Does This Leave Unknown? Total energy emitted in neutrinos? Partition between flavors? Emission in other particles? Spectrum of neutrinos? Neutrino mixing effects? ! Supernova explosion mechanism? Nucleosynthesis yields? Neutron star or black hole? Electromagnetic counterpart? Gravitational wave counterpart? ! and much more! John Beacom, The Ohio State University IceCube Particle Astrophysics, Madison, May 2017 3 Plan of the Talk ✔ Introduction: Three detection modes Revolutionizing MeV neutrino astronomy Milky Way burst Nearby galaxy mini-burst Diffuse Supernova Neutrino Background Concluding perspectives John Beacom, The Ohio State University IceCube Particle Astrophysics, Madison, May 2017 4 Introduction: Three Detection Modes John Beacom, The Ohio State University IceCube Particle Astrophysics, Madison, May 2017 5 Basic Features of MeV Neutrino Detection Detectors must be massive: Effectiveness depends on volume, not area Example signals: + ⌫ + e− ⌫ + e− ν¯ + p e + n ! e ! Detectors must be quiet: Need low natural and induced radioactivities Example background: A(Z, N) A(Z -
Supernovae and Neutrinos: the Crossroads John Beacom, the Ohio State University
Supernovae and Neutrinos: The Crossroads John Beacom, The Ohio State University John Beacom, The Ohio State University Supernova Neutrinos at the Crossroads, Trento, Italy, May 2019 1 Gateway: Astrophysics Neutron stars Black holes GW sources Cosmic rays Chemical elements Galaxy Feedback Supernovae John Beacom, The Ohio State University Supernova Neutrinos at the Crossroads, Trento, Italy, May 2019 2 Gateway: Particle Physics s Origin oF mass Mixing, CP violation Collective eFFects Dark matter New Forces New particles Neutrinos John Beacom, The Ohio State University Supernova Neutrinos at the Crossroads, Trento, Italy, May 2019 3 Crossroads Origin oF mass Neutron stars Mixing, CP violation Black holes Collective eFFects GW sources Dark matter Cosmic rays New Forces Chemical elements New particles Galaxy Feedback X Neutrinos Supernovae John Beacom, The Ohio State University Supernova Neutrinos at the Crossroads, Trento, Italy, May 2019 4 Why a Crossroads? To understand supernovae only neutrinos can reveal these extreme conditions To understand neutrinos only these extreme conditions can reveal particle properties John Beacom, The Ohio State University Supernova Neutrinos at the Crossroads, Trento, Italy, May 2019 5 Crossroads: Past Versus Future Are we ready? For Milky Way burst detection? To precisely detect the DSNB? To detect extragalactic minibursts? To advance multimessenger astrophysics? To probe physics beyond the standard model? To make neutrino astronomy real? What should we do diFFerently? John Beacom, The Ohio State University -
Eta Carinae and the Supernova Impostors
springer.com Kris Davidson, Roberta M. Humphreys (Eds.) 2012, X, 330 p. Eta Carinae and the Printed book Hardcover 149,99 € | £129.99 | $179.99 Supernova Impostors [1]160,49 € (D) | 164,99 € (A) | CHF 177,00 Series: Astrophysics and Space Science Library Softcover Provides a complete and up-to-date coverage of this famous and peculiar 140,17 € | £109.99 | $159.99 star: its ejecta, history, and physical state [1]149,98 € (D) | 154,19 € (A) | CHF Presents the connections with the instabilities and final stages in the most 165,50 massive stars, including the progenitors of supernovae and the "first" stars eBook Written by a team of prominent astronomers 117,69 € | £87.50 | $119.00 In 1965 Fritz Zwicky proposed a class of supernovae that he called "Type V", described as [2]117,69 € (D) | 117,69 € (A) | CHF "excessively faint at maximum". There were only two members, SN1961v and Eta Carinae. We 132,00 now know that Eta Carinae was not a true supernova, but if it were observed today in a distant Available from your library or galaxy we would call it a "supernova impostor". 170 years ago it experienced a "great eruption" springer.com/shop lasting 20 years, expelling 10 solar masses or more, and survived. Eta Carinae is now [3] MyCopy acknowledged as the most massive, most luminous star in our region of the Galaxy, and it may Printed eBook for just be our only example of a very massive star in a pre-supernova state. In this book the editors € | $ 24.99 and contributing authors review its remarkable history, physical state of the star and its ejecta, springer.com/mycopy and its continuing instability.