DETECTING the COMPANIONS and ELLIPSOIDAL VARIATIONS of RS Cvn PRIMARIES
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Explore the Universe Observing Certificate Second Edition
RASC Observing Committee Explore the Universe Observing Certificate Second Edition Explore the Universe Observing Certificate Welcome to the Explore the Universe Observing Certificate Program. This program is designed to provide the observer with a well-rounded introduction to the night sky visible from North America. Using this observing program is an excellent way to gain knowledge and experience in astronomy. Experienced observers find that a planned observing session results in a more satisfying and interesting experience. This program will help introduce you to amateur astronomy and prepare you for other more challenging certificate programs such as the Messier and Finest NGC. The program covers the full range of astronomical objects. Here is a summary: Observing Objective Requirement Available Constellations and Bright Stars 12 24 The Moon 16 32 Solar System 5 10 Deep Sky Objects 12 24 Double Stars 10 20 Total 55 110 In each category a choice of objects is provided so that you can begin the certificate at any time of the year. In order to receive your certificate you need to observe a total of 55 of the 110 objects available. Here is a summary of some of the abbreviations used in this program Instrument V – Visual (unaided eye) B – Binocular T – Telescope V/B - Visual/Binocular B/T - Binocular/Telescope Season Season when the object can be best seen in the evening sky between dusk. and midnight. Objects may also be seen in other seasons. Description Brief description of the target object, its common name and other details. Cons Constellation where object can be found (if applicable) BOG Ref Refers to corresponding references in the RASC’s The Beginner’s Observing Guide highlighting this object. -
A Decade of Starspot Activity on the Eclipsing Short-Period RS Canum Venaticorum Star WY Cancri: 1988-1997
Swarthmore College Works Physics & Astronomy Faculty Works Physics & Astronomy 3-1-1998 A Decade Of Starspot Activity On The Eclipsing Short-Period RS Canum Venaticorum Star WY Cancri: 1988-1997 P. A. Heckert G. V. Maloney M. C. Stewart J. I. Ordway Mary Ann Hickman Swarthmore College, [email protected] See next page for additional authors Follow this and additional works at: https://works.swarthmore.edu/fac-physics Part of the Astrophysics and Astronomy Commons Let us know how access to these works benefits ouy Recommended Citation P. A. Heckert, G. V. Maloney, M. C. Stewart, J. I. Ordway, Mary Ann Hickman, and M. Zeilik. (1998). "A Decade Of Starspot Activity On The Eclipsing Short-Period RS Canum Venaticorum Star WY Cancri: 1988-1997". Astronomical Journal. Volume 115, Issue 3. 1145-1152. DOI: 10.1086/300238 https://works.swarthmore.edu/fac-physics/213 This work is brought to you for free by Swarthmore College Libraries' Works. It has been accepted for inclusion in Physics & Astronomy Faculty Works by an authorized administrator of Works. For more information, please contact [email protected]. Authors P. A. Heckert, G. V. Maloney, M. C. Stewart, J. I. Ordway, Mary Ann Hickman, and M. Zeilik This article is available at Works: https://works.swarthmore.edu/fac-physics/213 THE ASTRONOMICAL JOURNAL, 115:1145È1152, 1998 March ( 1998. The American Astronomical Society. All rights reserved. Printed in U.S.A. A DECADE OF STARSPOT ACTIVITY ON THE ECLIPSING SHORT-PERIOD RS CANUM VENATICORUM STAR WY CANCRI: 1988È1997 PAUL A.HECKERT,M GEORGE V.ALONEY,S MARIA C. -
Technical Activities 1983 Center for Basic Standards
Technical Activities 1983 Center for Basic Standards U S. DEPARTMENT OF COMMERCE National Bureau of Standards National Measurement Laboratory Center for Basic Standards Washington, DC 20234 November 1983 Final Issued January 1984 Prepared for: U S. DEPARTMENT OF COMMERCE National Bureau of Standards Qc /ashington, DC 20234 1 00 -USk p p p I p p V i I » i » i i » i [i fi n NBSIR 83-2793 TECHNICAL ACTIVITIES 1983 CENTER FOR BASIC STANDARDS Karl G. Kessler, Director U.S. DEPARTMENT OF COMMERCE National Bureau of Standards National Measurement Laboratory Center for Basic Standards Washington, DC 20234 November 1 983 Final Issued January 1984 Prepared for: U.S. DEPARTMENT OF COMMERCE National Bureau of Standards Washington, DC 20234 U.S. DEPARTMENT OF COMMERCE, Malcolm Baidrige. Secretary NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director TABLE OF CONTENTS Part II Page Technical Activities: Introduction 1 Quantum Metrology Group 2 Electricity Division 21 Temperature and Pressure Division 81 Length and Mass Division 123 Time and Frequency Division 135 Quantum Physics Division 187 i i I 1 I II II i li 1 1 INTRODUCTION This book is Part II of the 1983 Annual Report of the Center for Basic Standards and contains a summary of the technical activities of the Center for the period October 1, 1982 to September 30, 1983. The Center is one of the five resources and operating units in the National Measurement Laboratory. The summary of activities is organized in six sections, one for the technical activities of the Quantum Metrology Group, and one each for the five divisions of the Center. -
Spot Activity of the RS Canum Venaticorum Star Σ Geminorum⋆
A&A 562, A107 (2014) Astronomy DOI: 10.1051/0004-6361/201321291 & c ESO 2014 Astrophysics Spot activity of the RS Canum Venaticorum star σ Geminorum P. Kajatkari1, T. Hackman1,2, L. Jetsu1,J.Lehtinen1, and G.W. Henry3 1 Department of Physics, PO Box 64, 00014 University of Helsinki, 00014 Helsinki, Finland e-mail: [email protected] 2 Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland 3 Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Blvd., Box 9501, Nashville, TN 37209, USA Received 14 February 2013 / Accepted 6 November 2013 ABSTRACT Aims. We model the photometry of RS CVn star σ Geminorum to obtain new information on the changes of the surface starspot distribution, that is, activity cycles, differential rotation, and active longitudes. Methods. We used the previously published continuous period search (CPS) method to analyse V-band differential photometry ob- tained between the years 1987 and 2010 with the T3 0.4 m Automated Telescope at the Fairborn Observatory. The CPS method divides data into short subsets and then models the light-curves with Fourier-models of variable orders and provides estimates of the mean magnitude, amplitude, period, and light-curve minima. These light-curve parameters are then analysed for signs of activity cycles, differential rotation and active longitudes. d Results. We confirm the presence of two previously found stable active longitudes, synchronised with the orbital period Porb = 19.60, and found eight events where the active longitudes are disrupted. The epochs of the primary light-curve minima rotate with a shorter d period Pmin,1 = 19.47 than the orbital motion. -
PDF Version in Chronological Order (Updated May 17, 2013)
Complete Bibliography for Ritter Observatory May 17, 2013 The following papers are based in whole or in part on observations made at Ritter Observatory. External collaborators are listed in parentheses unless the research was done while they were University of Toledo students. Refereed or invited: 1. A. H. Delsemme and J. L. Moreau 1973, Astrophys. Lett., 14, 181–185, “Brightness Profiles in the Neutral Coma of Comet Bennett (1970 II)” 2. B. W. Bopp and F. Fekel Jr. 1976, A. J., 81, 771–773, “HR 1099: A New Bright RS CVn Variable” 3. A. H. Delsemme and M. R. Combi 1976, Ap. J. (Letters), 209, L149–L151, “The Production Rate and Possible Origin of O(1D) in Comet Bennett 1970 II” 4. A. H. Delsemme and M. R. Combi 1976, Ap. J. (Letters), 209, L153–L156, “Production + Rate and Origin of H2O in Comet Bennett 1970 II” 5. D. W. Willmarth 1976, Pub. A. S. P., 88, 86–87, “The Orbit of 71 Draconis” 6. W. F. Rush and R. W. Thompson 1977, Ap. J., 211, 184–188, “Rapid Variations of Emission-Line Profiles in Nova Cygni 1975” 7. S. E. Smith and B. W. Bopp 1980, Pub. A. S. P., 92, 225–232, “A Microcomputer-Based System for the Automated Reduction of Astronomical Spectra” 8. B. W. Bopp and P. V. Noah 1980, Pub. A. S. P., 92, 333–337, “Spectroscopic Observations of the Surface-Activity Binary II Pegasi (HD 224085)” 9. M. R. Combi and A. H. Delsemme 1980, Ap. J., 237, 641–645, “Neutral Cometary Atmospheres. II. -
Downloads/ Astero2007.Pdf) and by Aerts Et Al (2010)
This work is protected by copyright and other intellectual property rights and duplication or sale of all or part is not permitted, except that material may be duplicated by you for research, private study, criticism/review or educational purposes. Electronic or print copies are for your own personal, non- commercial use and shall not be passed to any other individual. No quotation may be published without proper acknowledgement. For any other use, or to quote extensively from the work, permission must be obtained from the copyright holder/s. i Fundamental Properties of Solar-Type Eclipsing Binary Stars, and Kinematic Biases of Exoplanet Host Stars Richard J. Hutcheon Submitted in accordance with the requirements for the degree of Doctor of Philosophy. Research Institute: School of Environmental and Physical Sciences and Applied Mathematics. University of Keele June 2015 ii iii Abstract This thesis is in three parts: 1) a kinematical study of exoplanet host stars, 2) a study of the detached eclipsing binary V1094 Tau and 3) and observations of other eclipsing binaries. Part I investigates kinematical biases between two methods of detecting exoplanets; the ground based transit and radial velocity methods. Distances of the host stars from each method lie in almost non-overlapping groups. Samples of host stars from each group are selected. They are compared by means of matching comparison samples of stars not known to have exoplanets. The detection methods are found to introduce a negligible bias into the metallicities of the host stars but the ground based transit method introduces a median age bias of about -2 Gyr. -
THE RS CANUM VENATICORUM STARS 1. Introduction
THE RS CANUM VENATICORUM STARS MARCELLO RODONÖ Istituto di Astronomia, Universita degli Studi, and Osservatorio Astrofisico, 1-95125 Catania, Italy ABSTRACT. The picture emerging from recent studies of RS CVn-type systems indicates the presence of very active stars showing typical solar-like activity phenomena, such as spots and flares, and possibly mutual interactions. The binary nature of RS CVns is certainly important in enforcing high stellar rotation rates, but the actual clue to the understanding of the intrinsic variability of the component stars resides in their internal structure, where the appropriate physical conditions are met for the generation and inten- sification of strong magnetic fields, as prescribed by the aw-dynamo models. The most significant results have been derived from multi-wavelength, coordinated observations and long-term monitoring programs. Recent highlights include: a) the mapping of compact atmospheric structures at various temperature regimes by light curve modelling and spectral (Doppler) imaging techniques; 6) clear evidence of long-term activity cycles on RS CVn and other types of interacting binaries; c) the detection and measurement of surface magnetic fields, as derived from the differential Zeeman splitting of spectral lines. These results clearly demonstrate that the study of RS CVn stars can play a very fundamental role in the understanding of basic stellar physics, as well as in interpreting the characteristic variability of interacting binaries. 1. Introduction Since the discovery of the characteristic outside-of-eclipse photometric or distortion wave on the light curve of the RS CVn system at Catania Observatory (Rodono 1965, Chisari and Lacona 1965, Catalano and Rodono 1967) and the identification of the new class of binaries named after RS CVn (Oliver 1974, Hall 1976), a powerful astrophysical laboratory for the study of solar-like activity on other stars, in addition to the Sun, has become available. -
Radio Astronomvy 08Er O J an 2 8
'1 NATIONAL RADIO0 ASTRONOMY O BSERVAT 0 R Y FOURTH QUARTER REPORT October 1, 1984- December 31, 1984 RADIO ASTRONOMVY 08ER O CHARLOTTESVILLE, VA. JAN 2 8 -9, OBSERVING PROGRAM 140-foot Telescope Hours Scheduled observing 1739.00 Scheduled maintenance and equipment changes 185.25 Scheduled tests and calibration 190.75 Time lost due to: equipment failure 31.50 power 3.25 weather 40.75 interference 0.75 The following continuum programs were conducted during this quarter. No. Observer Program S279 D. Stinebring Observations at 10.65 GHz to search A. Wolszczan (NAIC) for steep spectrum, galactic sources near 1 = 23.5°. U19 J. Uson (Princeton) Continued search at 19.5 GHz for D. Wilkinson (Princeton) small-scale anisotropy of the micro- wave background. U20 J. Uson (Princeton) Observations of the Sunyaev-Zeldovich D. Wilkinson (Princeton) effect at 19.5 GHz. The following line programs were conducted during this quarter. No. Observer Program B428 L. Blitz (Maryland) Observations at 327 MHz to search for L. Armus (Maryland) interstellar deuterium and at 310 MHz V. Escalante-Ramirez (CFA) to search for the deuterated OH T. Hartquist (Maryland) molecule OD. S. Lepp (CFA) T. Hewagama (Maryland) C220 F. Clark (Kentucky) Observations at the 4 mainline fre- S. Miller (Kentucky) quencies of OH emission/absorption A. Bridle in bi-polar flows. H. Martin 13 W. Irvine (Massachusetts) Search at 1.7 cm for interstellar S. Madden (Massachusetts) ethylamine (NH 2 CCH). H. Matthews (Herzberg) D. Swade (Massachusetts) M231 I. Mirabel (Puerto Rico) Observations at 6 and 18 cm of high- L. Rodriguez (Mexico) velocity H2 CO and OH in regions of A. -
The RS Canum Venaticorum Binary HD 116204
J. Astrophys. Astr. (1987) 8, 389–395 The RS Canum Venaticorum Binary HD 116204 S. Mohin & Α. V. Raveendran Indian Institute of Astrophysics, Bangalore 560034 Received 1987 July 30; accepted 1987 November 13 Abstract. BV photometry of HD 116204 obtained on 57 nights during 1983–84, 1984–85 and 1986–87 observing season is presented. A photo- metric period of 21.9 ± 0.2 d and a mean (B – V)= 1.196 ± 0.010 are ob- tained. It is suggested that the binary HD 116204 has a mass ratio close to unity. Attempts are needed to detect the spectrum of secondary. Key words: BV photometry—HD 116204—RS CVn systems 1. Introduction A preliminary inspection of moderate-dispersion objective prism survey by Bidelman (1983) has shown the K2-type HD 116204 to be a Ca II emission star. In 1984 January we started observations of this star as part of a programme to study the photometric behaviour and chromospheric activity of late-type emission-line binaries. From the U B V photometry of this star its variability with a 21.7 day period has since been reported by Boyd, Genet & Hall (1984). Here we report on our BV photometric observations of HD 116204. 2. Observations HD 1 16204 was observed on a total of 57 nights during the three observing seasons 1983–84 (13 nights), 1984–85 (7 nights), and 1986–87 (37 nights) with the 34-cm reflector of Vainu Bappu Observatory, Kavalur, using standard Β and V filters. The comparison stars were HD 116494 (spectral type G5) and HD 115968 (spectral type K0). -
An Investigation of GSC 02038-00293, a Suspected RS Cvn Star, Using CCD Photometry
An investigation of GSC 02038-00293, a suspected RS CVn star, using CCD photometry. Alastair Bruce, Stewart Cruickshank, Tony Rodda and Mark Salisbury. (Members of the 2010 Open University Module S382 Undergraduate Programme). Abstract We present the results of differential, time series photometry for GSC 02038-00293, a suspected RS CVn binary, using data collected with the Open University's PIRATE robotic telescope located at the Observatori Astronomic de Mallorca between 10 May and 13 June 2010. A full orbital period cycle in the V band and partial cycle of B and R bands were obtained for GSC 02038-00293 showing an orbital period of 0.4955 +/- 0.0001 days. This period is in close agreement with that of previously published values but significantly different to that found by the All Sky Automated Survey of 0.330973 days. We suggest GSC 02038-00293 is a short period eclipsing RS CVn star and from our data alone we calculate an ephemeris of JD 2455327.614 + 0.4955(1) x E. We also find that the previously observed six to eight year cycle of star spot activity which accounts for the behaviour of the secondary minimum is closer to six years and that there is detectable reddening at both minima. Introduction We have undertaken a differential photometric study of GSC 02038-00293 known to display short period modulations in optical magnitude and to emit X-rays with a view to characterize the physical properties of this source. The target is located at RA 16h 02m 48.22s and Dec +25° 20’ 38.2’’ in the constellation of Serpens Caput. -
Local Numerical Modelling of Magnetoconvection and Turbulence - Implications for Mean-field Theories
Local numerical modelling of magnetoconvection and turbulence - implications for mean-field theories Petri J. K¨apyl¨a Department of Astronomy, Faculty of Science University of Helsinki Academic dissertation To be presented, with the permission of the Faculty of Science of the University of Helsinki, for public criticism in Auditorium XII on 13th October 2006, at 12 o’clock noon. Helsinki 2006 ISBN 952-10-3396-7 (paperback) ISBN 952-10-3397-5 (pdf) Helsinki 2006 Yliopistopaino Acknowledgements First, I would like to acknowledge the financial support from the Magnus Ehrnrooth foundation and the Finnish Graduate School for Astronomy and Space Physics during the thesis work. Furthermore, the Kiepenheuer-Institut f¨ur Sonnenphysik, DFG gradu- ate school “Nonlinear Differential Equations: Modelling, Theory, Numerics, Visualisa- tion”, and the Academy of Finland grant No. 1112020 are acknowledged for providing travel support. The hospitality of Observatoire Midi-Pyr´en´ees in Toulouse and Nordita in Copenhagen during my numerous visits is also acknowledged. Secondly, I wish to thank my supervisors, Dr. Maarit Korpi and Prof. Ilkka Tuominen for their invaluable help, ideas, and support during the thesis work. Furthermore, Prof. Michael Stix, whose knowledge, experience and integrity I greatly admire, deserves spe- cial thanks. I also wish to thank my collaborators Dr. Mathieu Ossendrijver for his help on various problems on physics and numerics, and Prof. Axel Brandenburg for discussions about life, universe and everything (among other things). Majority of the research for this thesis was done while I was staying at the Kiepenheuer- Institut f¨ur Sonnenphysik (KIS) in Freiburg. I wish to thank the staff of KIS for provid- ing a relaxed atmosphere for research and for the occasional movie- and football-related activities during my stay. -
Bibliography from ADS File: Engvold.Bib June 27, 2021 1
Bibliography from ADS file: engvold.bib Engvold, O., “The IAU Role”, 2007IAUS..236..467E ADS August 16, 2021 Martin, S. F., Engvold, O., & Lin, Y., “Comparisons of the Spines of Prominences (Filaments) in Hα and He II (304Å) Images”, 2007AAS...21012006M ADS Govender, K., Cheung, S.-L., Aretxaga, I., & Engvold, O., “Synergies among Martin, S. F., Lin, Y., & Engvold, O., “A Simple Method of Resolving the IAU Offices”, 2020IAUGA..30..563G ADS the 180 Degree Ambiguity Employing the Chirality of Solar Features”, Engvold, O., “IAU’s Interaction with Young Astronomers”, 2006SPD....37.0129M ADS 2019IAUS..349...75E ADS Lin, Y., Martin, S. F., & Engvold, O., ““Coronal Cloud” Prominences And Their Engvold, O., Vial, J.-C., & Skumanich, A.: 2019, Preface, xvii Association With Coronal Mass Ejections”, 2006SPD....37.0121L ADS 2019sgsp.bookD..17E ADS Lin, Y., Martin, S. F., Engvold, O., Rouppe van der Voort, L. H. M., & van Engvold, O. & Zirker, J. B.: 2019, Chapter 12.2 - High-Resolution Ground- Noort, M., “Dynamics of an active region filament, fibrils and surges in high Based Observations of the Sun, 419–441 2019sgsp.book..419E ADS resolution”, 2006cosp...36.3193L ADS Zirker, J. B. & Engvold, O.: 2019, Chapter 1 - Discoveries and Concepts: The Engvold, O., Harvey, J., Leibacher, J., et al., “Editorial Appreciation”, Sun’s Role in Astrophysics, 1–26 2019sgsp.book....1Z ADS 2006SoPh..233....1E ADS Engvold, O., Vial, J.-C., & Skumanich, A.: 2019, The Sun as a Guide to Stellar Martin, S. F. & Engvold, O., “Evidence for the Formation of Faint, High Promi- Physics 2019sgsp.book.....E ADS nences in the Aftermath of two Faint CMEs”, 2005AAS...20720401M Engvold, O.