DOCSLIB.ORG

Bibliography from ADS File: Linsky.Bib August 16, 2021 1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Bibliography from ADS file: linsky.bib Wilson, D. J., Froning, C., France, K., et al., “Measurements of the Ultra- August 16, 2021 violet Spectral Characteristics of Low-mass Exoplanetary Systems (Mega- MUSCLES)”, 2019ESS.....431906W ADS Edelman, E., Redfield, S., Linsky, J. L., Wood, B. E., & Müller, H., “Properties Wood, B. E., Müller, H.-R., Redfield, S., et al., “New Observational Constraints of the Interstellar Medium along Sight Lines to Nearby Planet-hosting Stars”, on the Winds of M dwarf Stars”, 2021ApJ...915...37W ADS 2019ApJ...880..117E ADS Duvvuri, G. M., Sebastian Pineda, J., Berta-Thompson, Z. K., et al., “Recon- Airapetian, V., Adibekyan, V., Ansdell, M., et al., “Reconstructing Extreme structing the Extreme Ultraviolet Emission of Cool Dwarfs Using Differential Space Weather From Planet Hosting Stars”, 2019BAAS...51c.564A ADS Emission Measure Polynomials”, 2021ApJ...913...40D ADS Osten, R., Bastian, T., Bower, G., et al., “Advancing Understanding of Star- Provornikova, E., Brandt, P. C., McNutt, Ralph L., J., et al., “Unique helio- Planet Ecosystems in the Next Decade: The Radio Wavelength Perspective”, physics science opportunities along the Interstellar Probe journey up to 1000 2019BAAS...51c.434O ADS AU from the Sun”, 2021EGUGA..2310504P ADS Rau, G., Montez, Rodolfo, J., Carpenter, K., et al., “Cool, evolved stars: results, Wilson, D. J., Froning, C. S., Duvvuri, G. M., et al., “The Mega-MUSCLES challenges, and promises for the next decade”, 2019BAAS...51c.241R Spectral Energy Distribution of TRAPPIST-1”, 2021ApJ...911...18W ADS ADS Drake, J., Alvarado-Gómez, J. D., Airapetian, V., et al., “High-Energy Tilipman, D., Vieytes, M., Linsky, J. L., Buccino, A., & France, K., “What M Photon and Particle Effects on Exoplanet Atmospheres and Habitability”, dwarf models reveal about their UV spectra?”, 2021csss.confE.294T 2019BAAS...51c.113D ADS ADS Carpenter, K., van Belle, G., Brown, A., et al., “Stars at High Spatial Resolu- Linsky, J., Wood, B. E., Youngblood, A., et al., “The Relative Emission tion”, 2019BAAS...51c..56C ADS from Chromospheres and Coronae: Dependence on Spectral Type and Age”, Froning, C. S., Kowalski, A., France, K., et al., “A Hot Ultraviolet Flare on the 2019ApJ...871L..26F 2021csss.confE.257L ADS M Dwarf Star GJ 674”, ADS Froning, C. S., Kowalski, A., France, K., et al., “A Hot Ultraviolet Flare on the Tilipman, D., Vieytes, M., Linsky, J. L., Buccino, A. P., & France, K., “Semiem- M Dwarf Star GJ 674”, 2019arXiv190108647F ADS pirical Modeling of the Atmospheres of the M Dwarf Exoplanet Hosts GJ 832 Linsky, J.: 2019, Host Stars and their Effects on Exoplanet Atmospheres, Vol. and GJ 581”, 2021ApJ...909...61T ADS 955 2019LNP...955.....L ADS Carleo, I., Youngblood, A., Redfield, S., et al., “A Multiwavelength Look at the Tilipman, D., Linsky, J. L., Vieytes, M., & France, K., “Comparison between GJ 9827 System: No Evidence of Extended Atmospheres in GJ 9827b and d panchromatic spectra of early- and late-M stars”, 2019AAS...23336507T from HST and CARMENES Data”, 2021AJ....161..136C ADS ADS Linsky, J., Wood, B., Youngblood, A., et al., “The Relative Emission from Loyd, R. O. P., France, K., Youngblood, A., et al., “The MUSCLES Chromospheres and Coronae: Dependence on Spectral Type and Age”, Treasury Survey. V. FUV Flares on Active and Inactive M Dwarfs”, 2021AAS...23714110L ADS 2018ApJ...867...71L ADS France, K., Fleming, B., Youngblood, A., et al., “EUV spectroscopy with the Tilipman, D., Linsky, J. L., Vieytes, M., & France, K., “Computing Mod- ESCAPE mission: exploring the stellar drivers of exoplanet habitability”, els of M-Type Host Stars and Their Panchromatic Spectral Output”, 2020SPIE11444E..05F ADS 2018LPICo2065.2034T ADS Melbourne, K., Youngblood, A., France, K., et al., “Estimating the Ul- Linsky, J., Tilipman, D., & France, K., “Computing Models of M-type Host Stars traviolet Emission of M Dwarfs with Exoplanets from Ca II and Hα”, and their Panchromatic Spectral Output”, 2018AAS...23231703L ADS 2020AJ....160..269M ADS Zachary, J., Redfield, S., Linsky, J. L., & Wood, B. E., “Measuring the Local Redfield, S., Vannier, H. N. N., & Linsky, J. L., “A Look at the Local In- ISM along the Sight Lines of the Two Voyager Spacecraft with HST/STIS”, terstellar Medium that Encompassed the Sun in Our Recent Past in or- 2018ApJ...859...42Z ADS der to Understand Our Current and Future Interstellar Surroundings”, Linsky, J. L., “UV astronomy throughout the ages: a historical perspective”, 2020AGUFMSH019..07R ADS 2018Ap&SS.363..101L ADS France, K., Duvvuri, G., Egan, H., et al., “The High-energy Radia- Osten, R. A., Crosley, M. K., Gudel, M., et al., “The ngVLA’s Role in Exoplanet tion Environment around a 10 Gyr M Dwarf: Habitable at Last?”, Science: Constraining Exo-Space Weather”, 2018arXiv180305345O 2020AJ....160..237F ADS ADS Linsky, J. L., Wood, B. E., Youngblood, A., et al., “The Relative Emission Youngblood, A., France, K., Loyd, R. O. P., et al., “VizieR Online Data Catalog: from Chromospheres and Coronae: Dependence on Spectral Type and Age”, MUSCLES Treasury Survey. IV. M dwarf UV fluxes (Youngblood+, 2017)”, 2020ApJ...902....3L ADS 2018yCat..18430031Y ADS Linsky, J. L., Redfield, S., & Wood, B. E., “New results concerning the environ- Linsky, J. L., “The Development of New Atmospheric Models for K and M ment of the heliosphere, nearby interstellar clouds, and physical processes in DwarfStars with Exoplanets”, 2018AAS...23142405L ADS the inter???cloud medium”, 2020JPhCS1620a2010L ADS France, K., Arulanantham, N., Fossati, L., et al., “Chromospheric and Transition Linsky, J. & Redfield, S., “What lies immediately outside of the heliosphere Region Emission Properties of G, K, and M dwarf Exoplanet Host Stars”, in the very local interstellar medium (VLISM): What will ISP detect?”, 2018AAS...23134906F ADS 2020EPSC...14...68L ADS Linsky, J.: 2017a, Model Atmospheres and Spectral Irradiance Library of the Redfield, S., Konow, F., Linsky, J. L., Wood, B. E., & Youngblood, A.: Exoplanet Host Stars Observed in the MUSCLES Survey, HST Proposal 2020, A SNAP Survey of the Local Interstellar Medium: New NUV 2017hst..prop15038L ADS Observations of Stars with Archived FUV Observations, HST Proposal Linsky, J. L., “Stellar Model Chromospheres and Spectroscopic Diagnostics”, 2017ARA&A..55..159L 2020hst..prop16225R ADS ADS Youngblood, A., France, K., Loyd, R. O. P., et al., “The MUSCLES Treasury Linsky, J., “What lies immediately outside of the heliosphere in the very Survey. IV. Scaling Relations for Ultraviolet, Ca II K, and Energetic Particle local interstellar medium (VLISM): morphology of the Local Interstel- Fluxes from M Dwarfs”, 2017ApJ...843...31Y ADS lar Cloud, its hydrogen hole, Stromgren Shells, and 60Fe accretion”, Linsky, J., “What Can TRAPPIST-1 Tell Us About Radiation From M-Dwarf 2020EGUGA..22.1410L ADS Chromospheres And Coronae”, 2017reph.conf20103L ADS Linsky, J., Redfield, S., & Tilipman, D., “The interface between the outer he- Zachary, J., Redfield, S., & Linsky, J., “Measuring the local ISM liosphere and the inner LISM: Morphology of the LIC, its hydrogen hole, along the sight lines of the two Voyager spacecraft with HST/STIS”, 2020AAS...23544201L Stromgren shells, and 60Fe accretion”, ADS 2017AAS...22934034Z ADS Konow, F., Redfield, S., & Linsky, J., “Constructing a Survey of the Local Inter- Fontenla, J. M., Linsky, J. L., Witbrod, J., et al., “Semi-empirical Modeling of the stellar Medium using Hubble Spectra”, 2020AAS...23536807K ADS Photosphere, Chromosphere, Transition Region, and Corona of the M-dwarf Tilipman, D., Vieytes, M., & Linsky, J. L., “Semi-Empirical Modeling of the Host Star GJ 832”, 2016ApJ...830..154F ADS M Dwarf Exoplanet Hosts GJ 832, GJ 581, and GJ 876: UV Radiation and Fontenla, J. M., Linsky, J. L., Witbrod, J., et al., “Semi-empirical Modeling of the Implications for Exoplanet Atmospheres”, 2020AAS...23535208T ADS Photosphere, Chromosphere, Transition Region, and Corona of the M-dwarf Vannier, H. N., Redfield, S., Wood, B. E., et al., “Mapping the Local Interstellar Host Star GJ 832”, 2016arXiv160800934F ADS Medium: Using Hubble to Look Back at the ISM Along the Sun’s Historical Linsky, J., “Prospects for ALMA Studies of the Solar-Stellar Connection”, Trajectory”, 2019AGUFMSH51E3323V ADS 2016csss.confE..81L ADS Linsky, J. L., Redfield, S., & Tilipman, D., “The Interface between the France, K., Arulanantham, N., Fossati, L., et al.: 2016, A SNAP UV Spectroscopic Outer Heliosphere and the Inner Local ISM: Morphology of the Local In- Study of Star-Planet Interactions, HST Proposal 2016hst..prop14633F terstellar Cloud, Its Hydrogen Hole, Strömgren Shells, and 60Fe Accretion”, ADS 2019ApJ...886...41L ADS Loyd, R. O. P., France, K., Youngblood, A., et al., “The MUSCLES Treasury Carpenter, K. G., van Belle, G., Brown, A., et al., “Stars at High Spatial Reso- Survey. III. X-Ray to Infrared Spectra of 11 M and K Stars Hosting Planets”, lution”, 2019arXiv190805665C ADS 2016ApJ...824..102L ADS 1 Youngblood, A., France, K., Loyd, R. O. P., et al., “The MUSCLES Treasury Linsky, J. L., France, K., & Ayres, T., “Reconstructing the Stellar UV and Survey. II. Intrinsic LYα and Extreme Ultraviolet Spectra of K and M Dwarfs EUV Emission that Controls the Chemistry of Exoplanet Atmospheres”, with Exoplanets*”, 2016ApJ...824..101Y ADS 2014IAUS..293..309L ADS Linsky, J., Fontenla, J., & France, K., “A semi-empirical model for the M star Linsky, J., “The solar-exoplanet-host-star connection: measurements, recon- GJ832 using modeling tools developed for computing semi-empirical solar struction, and estimates of the UV, Lyman-alpha, and EUV radiation emitted models”, 2016SPD....47.0105L ADS by exoplanet host stars”, 2014ebi..confP2.35L ADS Wood, B. E. & Linsky, J. L.: 2016, Astrospheres, stellar winds, and the interstel- Rugheimer, S., Kaltenegger, L., Linsky, J., & Mohanty, S., “Influence of UV lar medium, 56–79 2016hasa.book...56W ADS activity on the Spectral Fingerprints of Earth-like Planets around M dwarfs”, France, K., Loyd, R. O. P., Youngblood, A., et al., “The MUSCLES Treasury 2014ebi..conf..2.6R ADS Survey. I.
Recommended publications
  • Chemical Evolution of Protoplanetary Disks-The Effects of Viscous Accretion, Turbulent Mixing and Disk Winds

    Chemical Evolution of Protoplanetary Disks-The Effects of Viscous Accretion, Turbulent Mixing and Disk Winds

    Draft version June 5, 2018 Preprint typeset using LATEX style emulateapj v. 11/10/09 CHEMICAL EVOLUTION OF PROTOPLANETARY DISKS – THE EFFECTS OF VISCOUS ACCRETION, TURBULENT MIXING AND DISK WINDS D. Heinzeller1 and H. Nomura Department of Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan and C. Walsh and T. J. Millar Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN, UK Draft version June 5, 2018 ABSTRACT We calculate the chemical evolution of protoplanetary disks considering radial viscous accretion, vertical turbulent mixing and vertical disk winds. We study the effects on the disk chemical structure when different models for the formation of molecular hydrogen on dust grains are adopted. Our gas- phase chemistry is extracted from the UMIST Database for Astrochemistry (Rate06) to which we have added detailed gas-grain interactions. We use our chemical model results to generate synthetic near- and mid-infrared LTE line emission spectra and compare these with recent Spitzer observations. Our results show that if H2 formation on warm grains is taken into consideration, the H2O and OH abundances in the disk surface increase significantly. We find the radial accretion flow strongly influences the molecular abundances, with those in the cold midplane layers particularly affected. On the other hand, we show that diffusive turbulent mixing affects the disk chemistry in the warm molecular layers, influencing the line emission from the disk and subsequently improving agreement with observations. We find that NH3, CH3OH, C2H2 and sulphur-containing species are greatly enhanced by the inclusion of turbulent mixing.
  • La Constellation Du Taureau

    La Constellation Du Taureau

    La constellation du Taureau La constellation zodiacale du Taurus – le Taureau – est parfaitement visible sous les deux hémisphères d’avril à février. (1) Un peu de mythologie Selon la légende, l’œil rouge du puissant Taureau surveille Orion, le Chasseur, des avances duquel il veut protéger les Sept Sœurs – les Pléiades -. Le cœur d’Orion est tourné vers Mérope, l’une des sœurs dont il veut faire sa femme cependant qu’au bord de l’Amas des Pléiades, les parents de celle-ci le Titan Atlas et l’Océanide Pléioné – les observent attentivement. Des sept Pléiades, jeunes étoiles bleues saphir, seule Mérope a épousé un mortel, le roi de Corinthe, aussi cache-t-elle sa honte derrière une fine nébuleuse par réflexion. (2) (1) et (2) L’exploration du ciel, Robert Burnham, Alan Dyer, Robert A. Garfinkle, Martin George, Jeff Kanipi, David H. Levy. Édition Konemann, page 202. Chez les Babyloniens, le fermier (maintenant le Bélier) guide un Taureau qui manœuvre une charrue céleste creusant un sillon dans le ciel le long de l’écliptique. (3) Les Hyades sont les filles du dieu Atlas et de Pléione. Elles étaient 15 et avaient un frère nommé Hyas. Quand Hyas fut tué par un lion cinq des filles étaient inconsolables et ont été mises dans le ciel près de Hyas (constellation du Verseau) et ont été appelées les Hyades pour faire honneur à leur frère. Les sœurs qui restèrent pleuraient celles qui avaient été placées dans le ciel et à leur tour, s’y retrouvèrent et sont devenues les Pléiades. (4) (3) et (4) L’Observateur, revue électronique, http://astrosurf.com/duplessis/observateur/revue.html Volume 3, numéro 3, Constellation et ses étoiles, Rachelle Léger de la SAPM, page 2 Les Hyades (Mel 25) et les Pléiades (M 45) sont deux objets du ciel profond apparaissant dans le catalogue d’observation du CAABM.
  • Mathématiques Et Espace

    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.
  • Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation

    Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation

    Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born.
  • Explore the Universe Observing Certificate Second Edition

    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.
  • NASA's Goddard Space Flight Center Laboratory for High Energy

    NASA's Goddard Space Flight Center Laboratory for High Energy

    1 NASA’s Goddard Space Flight Center Laboratory for High Energy Astrophysics Greenbelt, Maryland 20771 @S0002-7537~99!00301-7# This report covers the period from July 1, 1997 to June 30, Toshiaki Takeshima, Jane Turner, Ken Watanabe, Laura 1998. Whitlock, and Tahir Yaqoob. This Laboratory’s scientific research is directed toward The following investigators are University of Maryland experimental and theoretical research in the areas of X-ray, Scientists: Drs. Keith Arnaud, Manuel Bautista, Wan Chen, gamma-ray, and cosmic-ray astrophysics. The range of inter- Fred Finkbeiner, Keith Gendreau, Una Hwang, Michael Loe- ests of the scientists includes the Sun and the solar system, wenstein, Greg Madejski, F. Scott Porter, Ian Richardson, stellar objects, binary systems, neutron stars, black holes, the Caleb Scharf, Michael Stark, and Azita Valinia. interstellar medium, normal and active galaxies, galaxy clus- Visiting scientists from other institutions: Drs. Vadim ters, cosmic-ray particles, and the extragalactic background Arefiev ~IKI!, Hilary Cane ~U. Tasmania!, Peter Gonthier radiation. Scientists and engineers in the Laboratory also ~Hope College!, Thomas Hams ~U. Seigen!, Donald Kniffen serve the scientific community, including project support ~Hampden-Sydney College!, Benzion Kozlovsky ~U. Tel such as acting as project scientists and providing technical Aviv!, Richard Kroeger ~NRL!, Hideyo Kunieda ~Nagoya assistance to various space missions. Also at any one time, U.!, Eugene Loh ~U. Utah!, Masaki Mori ~Miyagi U.!, Rob- there are typically between twelve and eighteen graduate stu- ert Nemiroff ~Mich. Tech. U.!, Hagai Netzer ~U. Tel Aviv!, dents involved in Ph.D. research work in this Laboratory. Yasushi Ogasaka ~JSPS!, Lev Titarchuk ~George Mason U.!, Currently these are graduate students from Catholic U., Stan- Alan Tylka ~NRL!, Robert Warwick ~U.
  • Long-Term Activity in Photospheres of Low-Mass Stars with Strong Magnetic Fields

    Long-Term Activity in Photospheres of Low-Mass Stars with Strong Magnetic Fields

    Geomagnetism and Aeronomy, 2020, Vol. 60, No. 7 LONG-TERM ACTIVITY IN PHOTOSPHERES OF LOW-MASS STARS WITH STRONG MAGNETIC FIELDS N. I. Bondar’1*, M. M. Katsova2** Abstract The behavior of the average annual luminosity of K–M dwarfs OU Gem, EQ Vir, V1005 Ori and AU Mic was studied at time intervals of several decades. The main sources of photometric data for 1989–2019 were the Hipparcos, ASAS, KWS databases. An analysis of long-term series showed that the average annual brightness of all stars varies cyclical. The durations of possible cycles for OU Gem, V1005 Ori and AU Mic are 40–42 years, for EQ Vir – 16.6 years, and amplitudes of cycles are of 0.09–0.2m. The selected stars belong to the group of red dwarfs for which the average surface magnetic field hBi exceeds of several kilogauss. We examined the type of the relationship between the parameters of the cycle, its duration and amplitude, for 9 stars with hBi < 4 kG. A tendency to increasing of the amplitude and duration of the cycle when the value of hBi decrease has been noted. It may be suggested that with an increasing of the surface magnetic field, it becomes more uniform and the level of activity changes in this case in less degrees than on stars with strong local fields concentrated in large spots. Keywords stars: activity – stars: cycles – stars: starspots – techniques: photometry 1 Crimean Astrophysical Observatory RAS, Nauchny, Russia 2 Sternberg State Astronomical Institute, Lomonosov Moscow State University, Moscow, Russia *e-mail: [email protected] **e-mail: [email protected] Received: March 07, 2020.
  • A Decade of Starspot Activity on the Eclipsing Short-Period RS Canum Venaticorum Star WY Cancri: 1988-1997

    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.
  • Observations of T-Tauri Stars Using HST-GHRS: II. Optical and Near UV Lines David R

    Observations of T-Tauri Stars Using HST-GHRS: II. Optical and Near UV Lines David R

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Submitted to ApJ Observations of T-Tauri Stars using HST-GHRS: II. Optical and Near UV lines David R. Ardila1, Gibor Basri2, Frederick M. Walter3, Jeff A. Valenti4, Christopher M. Johns-Krull5 ABSTRACT We have analyzed GHRS data of eight Classical T Tauri stars (CTTSs) and one Weak T Tauri star (WTTS). The GHRS data consist of an spectral range 40 A˚ wide centered on 2800 A.˚ For 4 of the CTTS we have nearly simultaneous optical observations which contain Hα,Hβ,HeI,NaD,andtheCaII infrared triplet. The Mg II resonance doublet is the strongest feature in the 2800 A˚ range. This line has a fairly wide and symmetric emission component ( 200 1 ∼ to 300 km s− for the CTTSs), with a narrow central absorption and a wide ∼ blueshifted absorption superimposed to it. The narrow central absorption width and equivalent width are inconsistent with being due only to ISM clouds described in the literature, which lead us to conclude that it is partially due to non-LTE processes in the emission line region itself. The emission profile closely follows Hα. Its large width in CTTS cannot be due to the Stark effect and we suggest that it is due to supersonic turbulence. All the stars show blueshifted absorptions 1 that are evidence of outflows (terminal velocities 300 km s− ), with multiple ∼ flows observed in two stars. We show evidence that the wind is not spherical, with wind signatures being stronger for lower inclinations at a given accretion rate.
  • Desert Skies Since 1954 Spring 2015 Volume LXI, Issue 1

    Desert Skies Since 1954 Spring 2015 Volume LXI, Issue 1

    Tucson Amateur Astronomy Association Observing our Desert Skies since 1954 Spring 2015 Volume LXI, Issue 1 Inside this issue: The Tadpoles in IC410 President’s 2 Letter Outreach 3, 5 New RideShare 7 Program Observing & 8 - 11 Imaging Featured 12, 14 Articles Classifieds 7 Sponsors 7 Contacts 15 Take Note! Science Fair and Book Festival Reports TAAA member Howard Bower photographed IC 410 which is found in Auriga TAAA RideShare Program using a Telescope Engineering Company TEC 140 ED apochromat refractor with Announced a field flattener resulting in f/7.4. This is a narrow band image with 34 exposures in Hydrogen Alpha (30 minutes each), 34 exposures in Oxygen III (binned 2x2 at Jupiter Opposition 2015 15 minutes each), and 34 exposures in Sulphur II (binned 2x2 at 15 minutes each). Report IC410 is a faint emission nebula surrounding the star cluster NGC 1893. At the Constellation of the top left of the nebula are two objects known as “The Tadpoles”. These are likely Season—Centaurus areas of stellar formation. Each tadpole is about 10 light years long. This object is at a distance of about 12,000 light years. © 2013 Howard Bower. Used by New Items in the Classifieds permission. Desert Skies Page 2 Volume LXI, Issue 1 From Our President As I reviewed the March Bulletin it was really heartwarming to see all of the activities in which we are involved. It takes a lot of Our mission is to provide opportunities for members dedication and hard work to put this all together and make it and the public to share the joy and excitement of work..
  • Optical Spectroscopic Monitoring Observations of a T Tauri Star V409 Tau

    Optical Spectroscopic Monitoring Observations of a T Tauri Star V409 Tau

    International Journal of Astronomy and Astrophysics, 2019, 9, 321-334 http://www.scirp.org/journal/ijaa ISSN Online: 2161-4725 ISSN Print: 2161-4717 Optical Spectroscopic Monitoring Observations of a T Tauri Star V409 Tau Hinako Akimoto, Yoichi Itoh Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, Hyogo, Japan How to cite this paper: Akimoto, H. and Abstract Itoh, Y. (2019) Optical Spectroscopic Mon- itoring Observations of a T Tauri Star V409 We report the results of optical spectroscopic monitoring observations of a T Tau. International Journal of Astronomy Tauri star, V409 Tau. A previous photometric study indicated that this star and Astrophysics, 9, 321-334. experienced dimming events due to the obscuration of light from the central https://doi.org/10.4236/ijaa.2019.93023 star with a distorted circumstellar disk. We conducted medium-resolution (R Received: July 24, 2019 ~10,000) spectroscopic observations with 2-m Nayuta telescope at Ni- Accepted: September 16, 2019 shi-Harima Astronomical Observatory. Spectra were obtained in 18 nights Published: September 19, 2019 between November 2015 and March 2016. Several absorption lines such as Ca Copyright © 2019 by author(s) and I and Li, and the Hα emission line were confirmed in the spectra. The Ic-band Scientific Research Publishing Inc. magnitudes of V409 Tau changed by approximately 1 magnitude during the This work is licensed under the Creative observation epoch. The equivalent widths of the five absorption lines are Commons Attribution International License (CC BY 4.0). roughly constant despite changes in the Ic-band magnitudes. We conclude http://creativecommons.org/licenses/by/4.0/ that the light variation of the star is caused by the obscuration of light from Open Access the central star with a distorted circumstellar disk, based on the relationship between the equivalent widths of the absorption lines and the Ic-band magni- tudes.
  • Apparent and Absolute Magnitudes of Stars: a Simple Formula

    Apparent and Absolute Magnitudes of Stars: a Simple Formula

    Available online at www.worldscientificnews.com WSN 96 (2018) 120-133 EISSN 2392-2192 Apparent and Absolute Magnitudes of Stars: A Simple Formula Dulli Chandra Agrawal Department of Farm Engineering, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi - 221005, India E-mail address: [email protected] ABSTRACT An empirical formula for estimating the apparent and absolute magnitudes of stars in terms of the parameters radius, distance and temperature is proposed for the first time for the benefit of the students. This reproduces successfully not only the magnitudes of solo stars having spherical shape and uniform photosphere temperature but the corresponding Hertzsprung-Russell plot demonstrates the main sequence, giants, super-giants and white dwarf classification also. Keywords: Stars, apparent magnitude, absolute magnitude, empirical formula, Hertzsprung-Russell diagram 1. INTRODUCTION The visible brightness of a star is expressed in terms of its apparent magnitude [1] as well as absolute magnitude [2]; the absolute magnitude is in fact the apparent magnitude while it is observed from a distance of . The apparent magnitude of a celestial object having flux in the visible band is expressed as [1, 3, 4] ( ) (1) ( Received 14 March 2018; Accepted 31 March 2018; Date of Publication 01 April 2018 ) World Scientific News 96 (2018) 120-133 Here is the reference luminous flux per unit area in the same band such as that of star Vega having apparent magnitude almost zero. Here the flux is the magnitude of starlight the Earth intercepts in a direction normal to the incidence over an area of one square meter. The condition that the Earth intercepts in the direction normal to the incidence is normally fulfilled for stars which are far away from the Earth.