DOCSLIB.ORG

The Diameter and Evolutionary State of Procyon A

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Diameter and Evolutionary State of Procyon A A&A 413, 251–256 (2004) Astronomy DOI: 10.1051/0004-6361:20031527 & c ESO 2003 Astrophysics The diameter and evolutionary state of Procyon A Multi-technique modeling using asteroseismic and interferometric constraints P. Kervella1,F.Th´evenin2,P.Morel2,G.Berthomieu2,P.Bord´e3, and J. Provost2 1 European Southern Observatory, Casilla 19001, Vitacura, Santiago 19, Chile 2 D´epartement Cassini, UMR CNRS 6529, Observatoire de la Cˆote d’Azur, BP 4229, 06304 Nice Cedex 4, France 3 LESIA, Observatoire de Paris-Meudon, 5, place Jules Janssen, 92195 Meudon Cedex, France Received 19 May 2003 / Accepted 20 August 2003 Abstract. We report the angular diameter measurement obtained with the VINCI/VLTI instrument on the nearby star Procyon A (α CMi A, F5IV–V), at a relative precision of 0:9%. We obtain a uniform disk angular diameter in the K band of θ = ± UD 5:376 0:047 mas and a limb darkened value of θLD = 5:448 0:053 mas. Together with the hipparcos parallax, this gives a linear± diameter of 2:048 0:025 D . We use this result in combination± with spectroscopic, photometric and asteroseismic constraints to model this star± with the CESAM code. One set of modeling parameters that reproduces the observations within their error bars are an age of 2314 Myr, an initial helium mass fraction Yi = 0:301 and an initial mass ratio of heavy elements to Z hydrogen ( X )i = 0:0314. We also computed the adiabatic oscillation spectrum of our model of Procyon A, giving a mean large frequency separation of ∆ν0 54:7 µHz. This value is in agreement with the seismic observations by Marti´c et al. (1999, 2001). The interferometric diameter≈ and the asteroseismic large frequency spacing together suggest a mass closer to 1.4 M than to 1.5 M . We conclude that Procyon is currently ending its life on the main sequence, as its luminosity class indicates. Key words. stars: individual: α CMi – stars: fundamental parameters – stars: evolution – techniques: interferometric 1. Introduction and metallicity Z of the star. We note that among the com- puted models only their model b is close to the mean large α Procyon A ( CMi, HD 61421, HIP 37279) is among the frequency spacing measured by M99–M01. Because numerous brightest stars in the sky and is easily visible to the naked new studies and observational constraints (like the direct di- eye. This made it an ideal target for a number of spectro- ameter) exist today, we re-examine the status of Procyon A in photometric calibration works. It is also a visual binary star helium content Y and in age. We first review and present the (ADS 6251A) classified F5 IV–V, with a white dwarf (WD) adopted fundamental parameters of Procyon A in Sect.2, part companion orbiting the main component in 40 years. The in- of them being used for the limb-darkening in Sect. 3, where fluence of this massive companion on the apparent motion of we present our new interferometric observations and the asso- Procyon was discovered by Bessel (1844). Girard et al. (2000) ciated data processing. In Sect. 4, we detail several models of have measured precisely the orbit of the pair, and obtained Procyon computed with the CESAM code (Morel 1997). These masses of 1:497 0:037 M and 0:602 0:015 M , respec- ± ± models are constrained using the spectroscopic effective tem- tively for Procyon A and B. It has also been an asteroseismic perature and the linear diameter value that we derived from the target since a decade and Martic et al. (1999 and 2001 here- VINCI/VLTI observations. Thus, we avoid to fit the luminosity after M99 and M01) have measured a large frequency spac- for which bolometric corrections are rather uncertain for stellar µ ing of respectively 55 and 54 Hz. These asteroseismic obser- luminosity class IV–V.A study of the asteroseismic frequencies vations provide strong constraints on stellar interior models, is then presented in Sect. 5, before the conclusion. and on macroscopic stellar parameters like mass and radius. Comparing the direct interferometric measurements of this star to its model diameter is therefore important to cross-validate both approaches. Matching Procyon’s position in the HR diagram has been 2. Fundamental parameters recognized as of great difficulty by Guenther & Demarque (1993, hereafter GD93). The reason is the poorly known mass Physical properties of Procyon A are well known thanks to the carefully measured orbit of the system and accurate hippar- Send offprint requests to: P. Kervella, cos parallax. Its mass has been recently measured by Girard e-mail: [email protected] et al. (2000) at MA = 1:497 0:037 M , adopting a parallax of ± Article published by EDP Sciences and available at http://www.aanda.org or http://dx.doi.org/10.1051/0004-6361:20031527 252 P. Kervella et al.: The diameter and evolutionary state of Procyon A 283:2 1:5 mas. This mass is computed using a large number Table 1. Relevant parameters of α CMi (Procyon) and its calibra- of observations± of inhomogeneous quality. The same authors, tor α CMa (Sirius). For Sirius, see also Kervella et al. (2003d). when they limit their observation sample to the excellent im- ages obtained with the WFPC2, found MA = 1:465 0:041 M . α CMi α CMa If we replace the parallax used by Girard et al. (2000)± by the HD 61421 HD 48915 parallax from the hipparcos catalogue, 285:93 0:88 mas, mV 0.34 1:47 ± m 0:65 −1:31 the sum of the masses of the binary decreases by 2.9%. K − − Spectral Type F5IV–V A1Vm Consequently, masses become respectively MA = 1:42 ± M(M )1:42 0:04 2:12 0:02 0:04 M for Procyon A and MB = 0:575 0:017 M for the ± ± ± T (K) 6530 50 9900 200 white dwarf Procyon B. Allende Prieto et al. (2002, hereafter eff ± ± log g 3.96 4.30 AP02), using the hipparcos parallax of Procyon A, have esti- [Fe=H] 0:05 0:03 0:50 0:20 mated its mass to be 1:42 0:06 M . From these works, we can − ± ± ± v sin i 3:16 0:50 16:0 1:0 conclude that the mass of Procyon is probably between 1.4 and πa (mas) 285:93± 0:88 379:22± 1:58 ± ± 1.5 M . Consequently, we investigate these two values in our θ (mas) 5:376 0:047 5:94 0:02b UD ± ± b study. The other adopted stellar parameters are summarized in θLD (mas) 5:448 0:053 6:04 0:02 Table 1. ± ± The bolometric luminosity is given by Steffen (1985) a Parallax values from hipparcos (Perryman et al. 1997). b Sirius θUD and θLD are taken from Kervella et al. (2003d). log(L?=L ) = 0:85 0:06. The photospheric properties of Procyon have been carefully± studied by AP02, who derived an effective temperature Teff = 6512 K. This value is based on the angular diameter measured in the visible by the Mark III except if the two stars have filled their Roche lobe, the mass of optical interferometer (Mozurkewich et al. 1991). Detailed 3D Procyon A has only been changed by a negligible amount. stellar atmosphere simulations have led AP02 to correct this The projected rotational velocity of Procyon A has been value of Teff by 80 K. Following their results, we adopt Teff = determined by many authors who derived values smaller 1 6530 50 K in our computations with a surface gravity of than 5.0 km s− . Considering in particular the value proposed ± 1 log g = 3:96 0:02. It is interesting to notice that over the last by AP02, v sin i = 3:2 0:5kms− , we conclude that twenty years,± the effective temperature estimates for Procyon Procyon A is a slow rotator± and we neglect the rotational ve- are spread between 6545 and 6811 K (Cayrel et al. 1997). locity in our modeling of its internal structure. The semi-major Adopting a color index of B V = 0:421 and using the cal- axis of the Procyon orbit being α 4: 5 (Girard et al. 2000), − ' 00 ibration by Alonso (1996) we find Teff = 6551 K which is very the distance between the two companions amounts to 16 au. close to the value proposed by AP02. The tidal interaction between the two components is therefore' The iron abundance at surface of [Fe=H] = 0:05 negligible. 0:03 dex with respect to the solar one is also taken from− AP02.± Therefore we adopt for the modeling of the internal structure 3. Interferometric angular diameter of Procyon A a chemical mixture which is calculated from the iron abundance using the approximation: 3.1. Instrumental setup and data processing ZFe Z ZFe The European Southern Observatory’s Very Large Telescope [Fe=H]s log + log log (1) Interferometer (Glindemann et al. 2000) is operated on top of ≡ Z s X s − X Z Z the Cerro Paranal, in Northern Chile, since March 2001. The log log observations reported here were done with two test siderostats ' X s − X (0.35 m aperture) and the VINCI beam combiner (Kervella et al. 2000, 2003a). The Procyon visibility measurements were where ZFe is the iron mass fraction within Z.Weusethesolar Z s all obtained on the B3–D3 baseline, 24 m in ground length. We Z mixture of Grevesse & Noels (1993) then X = 0:0245. As used a regular K band filter (λ = 2:0 2:4 µm) for these obser- we shall see in Sect.
Load more

Recommended publications
  • The Nearest Stars: a Guided Tour by Sherwood Harrington, Astronomical Society of the Pacific
    www.astrosociety.org/uitc No. 5 - Spring 1986 © 1986, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. The Nearest Stars: A Guided Tour by Sherwood Harrington, Astronomical Society of the Pacific A tour through our stellar neighborhood As evening twilight fades during April and early May, a brilliant, blue-white star can be seen low in the sky toward the southwest. That star is called Sirius, and it is the brightest star in Earth's nighttime sky. Sirius looks so bright in part because it is a relatively powerful light producer; if our Sun were suddenly replaced by Sirius, our daylight on Earth would be more than 20 times as bright as it is now! But the other reason Sirius is so brilliant in our nighttime sky is that it is so close; Sirius is the nearest neighbor star to the Sun that can be seen with the unaided eye from the Northern Hemisphere. "Close'' in the interstellar realm, though, is a very relative term. If you were to model the Sun as a basketball, then our planet Earth would be about the size of an apple seed 30 yards away from it — and even the nearest other star (alpha Centauri, visible from the Southern Hemisphere) would be 6,000 miles away. Distances among the stars are so large that it is helpful to express them using the light-year — the distance light travels in one year — as a measuring unit. In this way of expressing distances, alpha Centauri is about four light-years away, and Sirius is about eight and a half light- years distant.
    [Show full text]
  • XIII Publications, Presentations
    XIII Publications, Presentations 1. Refereed Publications E., Kawamura, A., Nguyen Luong, Q., Sanhueza, P., Kurono, Y.: 2015, The 2014 ALMA Long Baseline Campaign: First Results from Aasi, J., et al. including Fujimoto, M.-K., Hayama, K., Kawamura, High Angular Resolution Observations toward the HL Tau Region, S., Mori, T., Nishida, E., Nishizawa, A.: 2015, Characterization of ApJ, 808, L3. the LIGO detectors during their sixth science run, Classical Quantum ALMA Partnership, et al. including Asaki, Y., Hirota, A., Nakanishi, Gravity, 32, 115012. K., Espada, D., Kameno, S., Sawada, T., Takahashi, S., Ao, Y., Abbott, B. P., et al. including Flaminio, R., LIGO Scientific Hatsukade, B., Matsuda, Y., Iono, D., Kurono, Y.: 2015, The 2014 Collaboration, Virgo Collaboration: 2016, Astrophysical Implications ALMA Long Baseline Campaign: Observations of the Strongly of the Binary Black Hole Merger GW150914, ApJ, 818, L22. Lensed Submillimeter Galaxy HATLAS J090311.6+003906 at z = Abbott, B. P., et al. including Flaminio, R., LIGO Scientific 3.042, ApJ, 808, L4. Collaboration, Virgo Collaboration: 2016, Observation of ALMA Partnership, et al. including Asaki, Y., Hirota, A., Nakanishi, Gravitational Waves from a Binary Black Hole Merger, Phys. Rev. K., Espada, D., Kameno, S., Sawada, T., Takahashi, S., Kurono, Lett., 116, 061102. Y., Tatematsu, K.: 2015, The 2014 ALMA Long Baseline Campaign: Abbott, B. P., et al. including Flaminio, R., LIGO Scientific Observations of Asteroid 3 Juno at 60 Kilometer Resolution, ApJ, Collaboration, Virgo Collaboration: 2016, GW150914: Implications 808, L2. for the Stochastic Gravitational-Wave Background from Binary Black Alonso-Herrero, A., et al. including Imanishi, M.: 2016, A mid-infrared Holes, Phys.
    [Show full text]
  • Concepts & Synthesis
    CONCEPTS & SYNTHESIS EMPHASIZING NEW IDEAS TO STIMULATE RESEARCH IN ECOLOGY Ecological Monographs, 81(3), 2011, pp. 349–405 Ó 2011 by the Ecological Society of America Regulation of animal size by eNPP, Bergmann’s rule, and related phenomena 1,3 2 MICHAEL A. HUSTON AND STEVE WOLVERTON 1Department of Biology, Texas State University, San Marcos, Texas 78666 USA 2University of North Texas, Department of Geography, Denton, Texas 76203-5017 USA Abstract. Bergmann’s rule, which proposes a heat-balance explanation for the observed latitudinal gradient of increasing animal body size with increasing latitude, has dominated the study of geographic patterns in animal size since it was first proposed in 1847. Several critical reviews have determined that as many as half of the species examined do not fit the predictions of Bergmann’s rule. We have proposed an alternative hypothesis for geographic variation in body size based on food availability, as regulated by the net primary production (NPP) of plants, specifically NPP during the growing season, or eNPP (ecologically and evolutionarily relevant NPP). Our hypothesis, ‘‘the eNPP rule,’’ is independent of latitude and predicts both spatial and temporal variation in body size, as well as in total population biomass, population growth rates, individual health, and life history traits of animals, including humans, wherever eNPP varies across appropriate scales of space or time. In the context of a revised interpretation of the global patterns of NPP and eNPP, we predict contrasting latitudinal correlations with body size in three distinct latitudinal zones. The eNPP rule explains body- size patterns that are consistent with Bergmann’s rule, as well as two distinct types of contradictions of Bergmann’s rule: the lack of latitudinal patterns within the tropics, and the decline in body size above approximately 608 latitude.
    [Show full text]
  • Chicago Wilderness Region Urban Forest Vulnerability Assessment
    United States Department of Agriculture CHICAGO WILDERNESS REGION URBAN FOREST VULNERABILITY ASSESSMENT AND SYNTHESIS: A Report from the Urban Forestry Climate Change Response Framework Chicago Wilderness Pilot Project Forest Service Northern Research Station General Technical Report NRS-168 April 2017 ABSTRACT The urban forest of the Chicago Wilderness region, a 7-million-acre area covering portions of Illinois, Indiana, Michigan, and Wisconsin, will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of urban trees and natural and developed landscapes within the Chicago Wilderness region to a range of future climates. We synthesized and summarized information on the contemporary landscape, provided information on past climate trends, and illustrated a range of projected future climates. We used this information to inform models of habitat suitability for trees native to the area. Projected shifts in plant hardiness and heat zones were used to understand how nonnative species and cultivars may tolerate future conditions. We also assessed the adaptability of planted and naturally occurring trees to stressors that may not be accounted for in habitat suitability models such as drought, flooding, wind damage, and air pollution. The summary of the contemporary landscape identifies major stressors currently threatening the urban forest of the Chicago Wilderness region. Major current threats to the region’s urban forest include invasive species, pests and disease, land-use change, development, and fragmentation. Observed trends in climate over the historical record from 1901 through 2011 show a temperature increase of 1 °F in the Chicago Wilderness region. Precipitation increased as well, especially during the summer.
    [Show full text]
  • Argops) Solution to the 2017 Astrodynamics Specialist Conference Student Competition
    AAS 17-621 THE ASTRODYNAMICS RESEARCH GROUP OF PENN STATE (ARGOPS) SOLUTION TO THE 2017 ASTRODYNAMICS SPECIALIST CONFERENCE STUDENT COMPETITION Jason A. Reiter,* Davide Conte,1 Andrew M. Goodyear,* Ghanghoon Paik,* Guanwei. He,* Peter C. Scarcella,* Mollik Nayyar,* Matthew J. Shaw* We present the methods and results of the Astrodynamics Research Group of Penn State (ARGoPS) team in the 2017 Astrodynamics Specialist Conference Student Competition. A mission (named Minerva) was designed to investigate Asteroid (469219) 2016 HO3 in order to determine its mass and volume and to map and characterize its surface. This data would prove useful in determining the necessity and usefulness of future missions to the asteroid. The mission was designed such that a balance between cost and maximizing objectives was found. INTRODUCTION Asteroid (469219) 2016 HO3 was discovered recently and has yet to be explored. It lies in a quasi-orbit about the Earth such that it will follow the Earth around the Sun for at least the next several hundred years providing many opportunities for relatively low-cost missions to the body. Not much is known about 2016 HO3 except a general size range, but its close proximity to Earth makes a scientific mission more feasible than other near-Earth objects. A Request For Proposal (RFP) was provided to university teams searching for cost-efficient mission design solutions to assist in the characterization of the asteroid and the assessment of its potential for future, more in-depth missions and possible resource utilization. The RFP provides constraints on launch mass, bus size as well as other mission architecture decisions, and sets goals for scientific mapping and characterization.
    [Show full text]
  • Chapter 16 the Sun and Stars
    Chapter 16 The Sun and Stars Stargazing is an awe-inspiring way to enjoy the night sky, but humans can learn only so much about stars from our position on Earth. The Hubble Space Telescope is a school-bus-size telescope that orbits Earth every 97 minutes at an altitude of 353 miles and a speed of about 17,500 miles per hour. The Hubble Space Telescope (HST) transmits images and data from space to computers on Earth. In fact, HST sends enough data back to Earth each week to fill 3,600 feet of books on a shelf. Scientists store the data on special disks. In January 2006, HST captured images of the Orion Nebula, a huge area where stars are being formed. HST’s detailed images revealed over 3,000 stars that were never seen before. Information from the Hubble will help scientists understand more about how stars form. In this chapter, you will learn all about the star of our solar system, the sun, and about the characteristics of other stars. 1. Why do stars shine? 2. What kinds of stars are there? 3. How are stars formed, and do any other stars have planets? 16.1 The Sun and the Stars What are stars? Where did they come from? How long do they last? During most of the star - an enormous hot ball of gas day, we see only one star, the sun, which is 150 million kilometers away. On a clear held together by gravity which night, about 6,000 stars can be seen without a telescope.
    [Show full text]
  • Planetary Defence Activities Beyond NASA and ESA
    Planetary Defence Activities Beyond NASA and ESA Brent W. Barbee 1. Introduction The collision of a significant asteroid or comet with Earth represents a singular natural disaster for a myriad of reasons, including: its extraterrestrial origin; the fact that it is perhaps the only natural disaster that is preventable in many cases, given sufficient preparation and warning; its scope, which ranges from damaging a city to an extinction-level event; and the duality of asteroids and comets themselves---they are grave potential threats, but are also tantalising scientific clues to our ancient past and resources with which we may one day build a prosperous spacefaring future. Accordingly, the problems of developing the means to interact with asteroids and comets for purposes of defence, scientific study, exploration, and resource utilisation have grown in importance over the past several decades. Since the 1980s, more and more asteroids and comets (especially the former) have been discovered, radically changing our picture of the solar system. At the beginning of the year 1980, approximately 9,000 asteroids were known to exist. By the beginning of 2001, that number had risen to approximately 125,000 thanks to the Earth-based telescopic survey efforts of the era, particularly the emergence of modern automated telescopic search systems, pioneered by the Massachusetts Institute of Technology’s (MIT’s) LINEAR system in the mid-to-late 1990s.1 Today, in late 2019, about 840,000 asteroids have been discovered,2 with more and more being found every week, month, and year. Of those, approximately 21,400 are categorised as near-Earth asteroids (NEAs), 2,000 of which are categorised as Potentially Hazardous Asteroids (PHAs)3 and 2,749 of which are categorised as potentially accessible.4 The hazards posed to us by asteroids affect people everywhere around the world.
    [Show full text]
  • The Sky Tonight
    MARCH POUTŪ-TE-RANGI HIGHLIGHTS Conjunction of Saturn and the Moon A conjunction is when two astronomical objects appear close in the sky as seen THE- SKY TONIGHT- - from Earth. The planets, along with the TE AHUA O TE RAKI I TENEI PO Sun and the Moon, appear to travel across Brightest Stars our sky roughly following a path called the At this time of the year, we can see the ecliptic. Each body travels at its own speed, three brightest stars in the night sky. sometimes entering ‘retrograde’ where they The brightness of a star, as seen from seem to move backwards for a period of time Earth, is measured as its apparent (though the backwards motion is only from magnitude. Pictured on the cover is our vantage point, and in fact the planets Sirius, the brightest star in our night sky, are still orbiting the Sun normally). which is 8.6 light-years away. Sometimes these celestial bodies will cross With an apparent magnitude of −1.46, paths along the ecliptic line and occupy the this star can be found in the constellation same space in our sky, though they are still Canis Major, high in the northern sky. millions of kilometres away from each other. Sirius is actually a binary star system, consisting of Sirius A which is twice the On March 19, the Moon and Saturn will be size of the Sun, and a faint white dwarf in conjunction. While the unaided eye will companion named Sirius B. only see Saturn as a bright star-like object (Saturn is the eighth brightest object in our Sirius is almost twice as bright as the night sky), a telescope can offer a spectacular second brightest star in the night sky, view of the ringed planet close to our Moon.
    [Show full text]
  • Ghost Imaging of Space Objects
    Ghost Imaging of Space Objects Dmitry V. Strekalov, Baris I. Erkmen, Igor Kulikov, and Nan Yu Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099 USA NIAC Final Report September 2014 Contents I. The proposed research 1 A. Origins and motivation of this research 1 B. Proposed approach in a nutshell 3 C. Proposed approach in the context of modern astronomy 7 D. Perceived benefits and perspectives 12 II. Phase I goals and accomplishments 18 A. Introducing the theoretical model 19 B. A Gaussian absorber 28 C. Unbalanced arms configuration 32 D. Phase I summary 34 III. Phase II goals and accomplishments 37 A. Advanced theoretical analysis 38 B. On observability of a shadow gradient 47 C. Signal-to-noise ratio 49 D. From detection to imaging 59 E. Experimental demonstration 72 F. On observation of phase objects 86 IV. Dissemination and outreach 90 V. Conclusion 92 References 95 1 I. THE PROPOSED RESEARCH The NIAC Ghost Imaging of Space Objects research program has been carried out at the Jet Propulsion Laboratory, Caltech. The program consisted of Phase I (October 2011 to September 2012) and Phase II (October 2012 to September 2014). The research team consisted of Drs. Dmitry Strekalov (PI), Baris Erkmen, Igor Kulikov and Nan Yu. The team members acknowledge stimulating discussions with Drs. Leonidas Moustakas, Andrew Shapiro-Scharlotta, Victor Vilnrotter, Michael Werner and Paul Goldsmith of JPL; Maria Chekhova and Timur Iskhakov of Max Plank Institute for Physics of Light, Erlangen; Paul Nu˜nez of Coll`ege de France & Observatoire de la Cˆote d’Azur; and technical support from Victor White and Pierre Echternach of JPL.
    [Show full text]
  • Updated Inflight Calibration of Hayabusa2's Optical Navigation Camera (ONC) for Scientific Observations During the C
    Updated Inflight Calibration of Hayabusa2’s Optical Navigation Camera (ONC) for Scientific Observations during the Cruise Phase Eri Tatsumi1 Toru Kouyama2 Hidehiko Suzuki3 Manabu Yamada 4 Naoya Sakatani5 Shingo Kameda6 Yasuhiro Yokota5,7 Rie Honda7 Tomokatsu Morota8 Keiichi Moroi6 Naoya Tanabe1 Hiroaki Kamiyoshihara1 Marika Ishida6 Kazuo Yoshioka9 Hiroyuki Sato5 Chikatoshi Honda10 Masahiko Hayakawa5 Kohei Kitazato10 Hirotaka Sawada5 Seiji Sugita1,11 1 Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan 2 National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan 3 Meiji University, Kanagawa, Japan 4 Planetary Exploration Research Center, Chiba Institute of Technology, Chiba, Japan 5 Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kanagawa, Japan 6 Rikkyo University, Tokyo, Japan 7 Kochi University, Kochi, Japan 8 Nagoya University, Aichi, Japan 9 Department of Complexity Science and Engineering, The University of Tokyo, Chiba, Japan 10 The University of Aizu, Fukushima, Japan 11 Research Center of the Early Universe, The University of Tokyo, Tokyo, Japan 6105552364 Abstract The Optical Navigation Camera (ONC-T, ONC-W1, ONC-W2) onboard Hayabusa2 are also being used for scientific observations of the mission target, C-complex asteroid 162173 Ryugu. Science observations and analyses require rigorous instrument calibration. In order to meet this requirement, we have conducted extensive inflight observations during the 3.5 years of cruise after the launch of Hayabusa2 on 3 December 2014. In addition to the first inflight calibrations by Suzuki et al. (2018), we conducted an additional series of calibrations, including read- out smear, electronic-interference noise, bias, dark current, hot pixels, sensitivity, linearity, flat-field, and stray light measurements for the ONC.
    [Show full text]
  • ANNUAL REPORT June 30, 2021
    JOB TITLE SA FUNDS AR REVISION 8 SERIAL <12345678> TIME Friday, August 27, 2021 JOB NUMBER 393837-1 TYPE PAGE NO. I ANNUAL REPORT June 30, 2021 PORTFOLIOS OF INVESTMENTS SA U.S. Fixed Income Fund SA Global Fixed Income Fund SA U.S. Core Market Fund SA U.S. Value Fund SA U.S. Small Company Fund SA International Value Fund SA International Small Company Fund SA Emerging Markets Value Fund SA Real Estate Securities Fund SA Worldwide Moderate Growth Fund Beginning on January 1, 2022, as permitted by regulations adopted by the Securities and Exchange Commission, we intend to no longer mail paper copies of each Fund’s shareholder reports, unless you specifically request paper copies of the reports from the SA Funds - Investment Trust (the “Trust”) or from your financial intermediary, such as a broker-dealer or bank. Instead, the reports will be made available on the Trust’s website (http://www.sa-funds.com), and you will be notified by mail each time a report is posted and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to continue to receive paper copies of all future reports free of charge. If you invest through a financial intermediary, you may contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the Trust, you may inform the Trust that you wish to continue receiving paper copies of your shareholder reports by contacting us at (844) 366-0905.
    [Show full text]
  • Planet Earth Taken by Hayabusa-2
    Space Science in JAXA Planet Earth May 15, 2017 taken by Hayabusa-2 Saku Tsuneta, PhD JAXA Vice President Director General, Institute of Space and Astronautical Science 2017 IAA Planetary Defense Conference, May 15-19,1 Tokyo 1 Brief Introduction of Space Science in JAXA Introduction of ISAS and JAXA • As a national center of space science & engineering research, ISAS carries out development and in-orbit operation of space science missions with other directorates of JAXA. • ISAS is an integral part of JAXA, and has close collaboration with other directorates such as Research and Development and Human Spaceflight Technology Directorates. • As an inter-university research institute, these activities are intimately carried out with universities and research institutes inside and outside Japan. ISAS always seeks for international collaboration. • Space science missions are proposed by researchers, and incubated by ISAS. ISAS plays a strategic role for mission selection primarily based on the bottom-up process, considering strategy of JAXA and national space policy. 3 JAXA recent science missions HAYABUSA 2003-2010 AKARI(ASTRO-F)2006-2011 KAGUYA（SELENE)2007-2009 Asteroid Explorer Infrared Astronomy Lunar Exploration IKAROS 2010 HAYABUSA2 2014-2020 M-V Rocket Asteroid Explorer Solar Sail SUZAKU(ASTRO-E2)2005- AKATSUKI 2010- X-Ray Astronomy Venus Meteorogy ARASE 2016- HINODE(SOLAR-B)2006- Van Allen belt Solar Observation Hisaki 2013 4 Planetary atmosphere Close ties between space science and space technology Space Technology Divisions Space
    [Show full text]