DOCSLIB.ORG

H LO CM I Publications OFTHE Astronomical Society

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
H LO CM I Publications OFTHE Astronomical Society >H CMLO i Publications OFTHE Astronomical Society of the Pacific CTi 99:425-438, May 1987 S< THE SPECTRAL VARIATIONS OF THE DELTA SCUTI STAR RHO PUPPIS r-cu \—Is s. YANG,* G. A. H. WALKER,* AND P. BENNETT Department of Geophysics and Astronomy, University of British Columbia, Vancouver, BC V6T 1W5, Canada Received 1986 December 12, revised 1987 February 9 ABSTRACT Precise differential radial velocities of the sharp-lined (υ sin ί = 14 km s _1) δ Scuti variable ρ Pup (P = 3.37 hours) with a time resolution < P/15givea2Kamplitude of 9.08 km s_1for Ca II λ8662 and 8.35 km s-1 for Η ΐλ8750. The amplitudes for the Fe I, Si I, and S I velocities are 9.46, 9.23, and 9.41 -1 1 -1 km s , respectively. The 2 Κ/Διηυ value of 93 km s mag is typical of a radial pulsator. The line intensities of the stellar lines vary out of phase with the observed radial velocities but closer in phase with the light curve. The amplitudes of the variations are between 0.3% and 1% of the continuum. Most lines are weaker near light maximum (temperature maximum) and stronger near light minimum (temperature minimum). The variations correspond to the changes in spectral type associated with the variations of eifective temperature over the pulsation cycle. A simple linear theory is developed in which the temperature dependence of both the stellar continuum opacity and line opacity are calculated. Key words: δ Scuti variable-radial velocities-equivalent widths I. Introduction metric data and derived a period of 0^14088141 (3.3712 The star ρ Puppis (HR 3185, HD 67523) is a small-am- hours) and a blue-light amplitude of 0.126 mag. The light plitude, sharp-lined {v sin ¿ = 14 km s ^), δ Scuti variable curve was found to be nearly sinusoidal with the maxi- with a spectral type of F5 Hp (Morgan and Abt 1972). The mum slightly sharper than the minimum. Both the rising star is similar to the proto-Am (δ Delphini-type) stars and descending branches of the curve are equally steep. which show anomalous metal abundances. The enhanced Bappu (1959) measured a light amplitude of 0.16 mag at metal abundance in ρ Pup has been confirmed by Green- λ4050 together with a 300 Κ change in the color tempera- stein (1948), Bessell (1969), Breger (1970), and Kurtz ture. The simultaneous photometric and spectroscopic (1976). A value of 0.54 dex has been determined for observations by Danziger and Kuhi (1966) give a 2 Κ value -1 [Fe/H] by Kurtz (1976) who also found deficiencies in of 11 km s , a light amplitude of 0.15 mag at λ4566, and Ca i, Se II, Ti π, and V π. Meanwhile, Bidelman (1951), an effective-temperature variation of ± 140 K. Minimum McNamara and Augason (1962), and Morgan and Abt light was found to occur at about 0.08 of a period before (1972) have all pointed out that Ca π is weak in ρ Pup maximum radial velocity. when compared to stars of similar spectral type. Bessell (1969), using simultaneous radial-velocity and The star ρ Pup was first reported to exhibit variable photoelectric spectrum-scanner observations of the con- radial velocities by Reese (1903) and Campbell and Moore tinuum, measured a light amplitude of 0.130 mag at (1928). These early Lick velocities suggested a 2 Κ value X4255 and a 2 Κ value of 9.5 km s_1. One can measure (the peak-to-peak radial-velocity amplitude) of 8.4 km s_1. from his data that the radial-velocity minimum lags the Meanwhile, Spencer Jones (1928) derived a 2 Κ value of light maximum by about 0.075 in phase. Bessell (1969) has 11.6 km s-1 from Cape observations. The data from also reported a temperature variation of ± 65 Κ and a Struve, Sahade, and Zebergs (1956) has a 2 Κ amplitude of radius variation, AR, of ± 8 X 103 km. Thulasi Doss 9.7 km s-1 and a period of 0?1409. Additional radial-veloc- (1969) observed the photometric variations in the narrow ity measurements were also reported by Buscombe passbands at λ3858, λ4310, λ4720, and λ5875. The corre- (1957). Photometric variations were first reported by sponding amplitudes were given as 0.17, 0.14, 0.12, and Cousins (1951) and Eggen (1956, 1957). Ponsen (1963) 0.09 mag, respectively. An effective-temperature varia- reanalyzed all the early data together with his own photo- tion of ± 160 Κ and a period of 0^14088667 were also derived. Trodahl and Sullivan (1977) measured a light *Visiting Astronomer, Canada-France-Hawaii Telescope, which is amplitude of 0.105 mag at X4850 and an effective-temper- operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique of France, and the University of ature variation of ± 90 K. A corresponding amplitude of Hawaii. about 0.033 was given for AR/R, the relative radius varia- 425 © Astronomical Society of the Pacific · Provided by the NASA Astrophysics Data System 426 YANG, WALKER, AND BENNETT tion. Dravins, Lind, and Sarg (1977), with simultaneous period of 0^141 (3.37 hours), respectively. Period cover- radial-velocity and photometric observations, have mea- age on the three nights was 83%, 112%, and 69%, respec- sured a phase lag of 0.06 between the radial-velocity tively. The mean S/N per diode (pixel) in the continuum of minimum and the light maximum. A temperature of ± each spectrum is 690, 800, and 400 for the three respec- 80 Κ was measured from the loop traveled by ρ Pup in the tive nights of observations. The midexposure time (in {c^ (b—y)) diagram over the pulsation cycle. Dravins et barycentric Julian day) of each observation is listed in al. (1977) also reported emission in the blue wing of the Table I. Ca π Κ line profile at about 0.28 in phase before maximum A spectrum of ρ Pup without the imposed HF lines is light. It has been suggested that the emission was caused shown in Figure 1. Lines from the same atomic or ionic by a shock wave propagating through the stellar atmo- species are indicated with the same number and are sphere (Dravins et al. 1977; Hill 1977; Smith 1982). identified in the caption. Simultaneous photometry and photoelectric radial veloc- The data reduction was performed using the program ities have also been given by Balona and Stobie (1983). RETICENT (Pritchet, Mochnacki, and Yang 1982). The With a Reticon detector, Campos and Smith (1980) mea- technique of preprocessing the Reticon spectra to obtain sured a 2 Κ value of 11.5 km s-1 from the Fe I λ4476 and the optimum S/N has been described in Walker et al. Fe π λ4508 lines. No line width or line-profile variation (1985). The procedure to measure radial velocities from greater than 5% of the continuum was detected. the stellar + HF spectra has been described in Yang et al. Smith (1982) adopted, for ρ Pup, a Δτη^ value (the peak- (1982) and Yang and Walker (1986α,&). The same stan- to-peak light amplitude in V) of 0.102 mag and a phase dard stellar and lamp + HF spectra were used to measure difference of 0.08 between the light maximum and the the radial velocities from all of the spectra. This ensures radial-velocity minimum. Reay, Hicks, and Atherton internal consistency for the measured velocities between (1983) used a servo-controlled Fabry-Perot-radial-veloc- the three time series. ity spectrometer to measure the radial-velocity variations TABLE I of Pup with a precision of ± 20 m s_1. From 226 minutes ρ Relative Radial Velocities of ρ Puppis (3.76 hours) of observations, there was no evidence of periodicity other than the period of 0^141. Fracassini et Mid-exposure Ca II mean mean mean time λ8662 Fe I Si I S I al. (1983) have reported a time series of IUE high-disper- BJD2445356+ (kms"1) (kms"1) (kms"1) (kms-1) sion observations of the Mg π H and Κ lines. Emission in 0.90112 -1.118 -1.119 -0.855 -0.950 the cores of the lines was found to be present over the 0.90839 +0.245 +0.211 +0.341 +0.462 0.91564 +1.484 +1.508 +1.715 +1.846 entire pulsation cycle. These emissions increased with 0.92289 +2.590 +2.694 +2.956 +3.056 increasing luminosity of the star. 0.93021 +3.702 +3.824 +3.968 +4.007 0.93748 +4.525 +4.600 +4.695 +4.793 Because it is so bright (V = 2.82 mag), ρ Pup offers a 0.94473 +4.771 +4.860 +4.976 +5.002 0.95197 +4.758 +4.655 +4.871 +4.767 rather unique opportunity to apply high S/N spectra to 0.95921 +4.079 +3.866 +4.107 +4.017 0.96646 +2.898 +2.793 +2.713 +2.803 the study of δ S cuti pulsation. In this paper, we report the 0.97372 +1.521 +1.162 + 1 .309 + 1 .244 results obtained with spectra having S/N in the range 400 0.98097 -0.213 -0.571 -0.651 -0.603 0.98821 -1.948 -2.384 -2.234 -2.332 to 800 per pixel. Radial velocities of ρ Pup were measured 0.99545 -3.220 -3.674 -3.447 -3.663 1.00271 -4.105 -4.526 -4.310 -4.518 using the hydrogen fluoride (HF) absorption-cell tech- 1.00996 -4.361 -4.761 -4.629 -4.799 nique (Campbell and Walker 1979; Yang and Walker 1.01844 -4.137 -4.544 -4.256 -4.629 2.84152 -4.644 -4.772 -4.768 -4.686 1986a).
Load more

Recommended publications
  • Arxiv:1710.00185V1
    Accepted for publication in the Publications of the Astronomical Society of the Pacific, 21 July 2017 Preprint typeset using LATEX style emulateapj v. 05/12/14 PROJECT SOLARIS – A GLOBAL NETWORK OF AUTONOMOUS OBSERVATORIES – DESIGN, COMMISSIONING AND FIRST SCIENCE RESULTS S.K. Koz lowski1,2, P.W. Sybilski1,3, M. Konacki1,2,3, R.K. Paw laszek1,3, M. Ratajczak 4, K.G. He lminiak1 and M. Litwicki1,2 Accepted for publication in the Publications of the Astronomical Society of the Pacific, 21 July 2017 ABSTRACT We present the design and commissioning of Project Solaris, a global network of autonomous observatories. Solaris is a Polish scientific undertaking aimed at the detection and characterization of circumbinary exoplanets and eclipsing binary stars. To accomplish this task, a network of four fully autonomous observatories has beed deployed in the Southern Hemisphere: Solaris-1 and Solaris-2 in the South African Astronomical Observatory in South Africa, Solaris-3 in Siding Spring Observatory in Australia and Solaris-4 in Complejo Astronomico El Leoncito in Argentina. The four stations are nearly identical and are equipped with 0.5-m Ritchey-Cr´etien (f/15) or Cassegrain (f/9, Solaris-3) optics and high-grade 2K x 2K CCD cameras with Johnson and Sloan filter sets. We present the design and implementation of low-level security, data logging and notification systems, weather monitoring components, all-sky vision system, surveillance system and distributed temperature and humidity sensors. We describe dedicated grounding and lighting protection system design and robust fiber data transfer interfaces in electrically demanding conditions. We discuss the outcomes of our design as well as the resulting software engineering requirements.
    [Show full text]
  • Highlights of Discoveries for $\Delta $ Scuti Variable Stars from the Kepler
    Highlights of Discoveries for δ Scuti Variable Stars from the Kepler Era Joyce Ann Guzik1,∗ 1Los Alamos National Laboratory, Los Alamos, NM 87545 USA Correspondence*: Joyce Ann Guzik [email protected] ABSTRACT The NASA Kepler and follow-on K2 mission (2009-2018) left a legacy of data and discoveries, finding thousands of exoplanets, and also obtaining high-precision long time-series data for hundreds of thousands of stars, including many types of pulsating variables. Here we highlight a few of the ongoing discoveries from Kepler data on δ Scuti pulsating variables, which are core hydrogen-burning stars of about twice the mass of the Sun. We discuss many unsolved problems surrounding the properties of the variability in these stars, and the progress enabled by Kepler data in using pulsations to infer their interior structure, a field of research known as asteroseismology. Keywords: Stars: δ Scuti, Stars: γ Doradus, NASA Kepler Mission, asteroseismology, stellar pulsation 1 INTRODUCTION The long time-series, high-cadence, high-precision photometric observations of the NASA Kepler (2009- 2013) [Borucki et al., 2010; Gilliland et al., 2010; Koch et al., 2010] and follow-on K2 (2014-2018) [Howell et al., 2014] missions have revolutionized the study of stellar variability. The amount and quality of data provided by Kepler is nearly overwhelming, and will motivate follow-on observations and generate new discoveries for decades to come. Here we review some highlights of discoveries for δ Scuti (abbreviated as δ Sct) variable stars from the Kepler mission. The δ Sct variables are pre-main-sequence, main-sequence (core hydrogen-burning), or post-main-sequence (undergoing core contraction after core hydrogen burning, and beginning shell hydrogen burning) stars with spectral types A through mid-F, and masses around 2 solar masses.
    [Show full text]
  • Variable Star
    Variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: Intrinsic variables, whose luminosity actually changes; for example, because the star periodically swells and shrinks. Extrinsic variables, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes Trifid Nebula contains Cepheid variable stars eclipses it. Many, possibly most, stars have at least some variation in luminosity: the energy output of our Sun, for example, varies by about 0.1% over an 11-year solar cycle.[1] Contents Discovery Detecting variability Variable star observations Interpretation of observations Nomenclature Classification Intrinsic variable stars Pulsating variable stars Eruptive variable stars Cataclysmic or explosive variable stars Extrinsic variable stars Rotating variable stars Eclipsing binaries Planetary transits See also References External links Discovery An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary Algol.[2][3][4] Of the modern astronomers, the first variable star was identified in 1638 when Johannes Holwarda noticed that Omicron Ceti (later named Mira) pulsated in a cycle taking 11 months; the star had previously been described as a nova by David Fabricius in 1596. This discovery, combined with supernovae observed in 1572 and 1604, proved that the starry sky was not eternally invariable as Aristotle and other ancient philosophers had taught.
    [Show full text]
  • Variable Stars Across the Observational HR Diagram
    Variable stars across the observational HR diagram Laurent Eyer1, Nami Mowlavi1;2 1 Observatoire de Gen`eve, Universit´ede Gen`eve, 1290 Sauverny, Switzerland 2 ISDC, Universit´ede Gen`eve, 1290 Versoix, Switzerland E-mail: [email protected] Abstract. An overview of pulsating variable stars across the observational Hertzprung-Russel (HR) diagram is presented, together with a summary of their global properties. The HR diagram is presented with a third colour-coded dimension, visualizing the fraction of variable, the amplitude of variability or the period of variability. The distribution of variable stars in the other observational diagrams, such as the Period-Amplitude diagram, is also presented. Some of the progresses performed in the field of variable stars during the last decade are briefly summarized, and future projects that will improve our knowledge of variable stars are mentioned. 1. Introduction There are in the literature several global descriptions of variable stars. We can mention four books, one by Richter, Wenzel and Hoffmeister (1985, out of print), one by Sterken and Jaschek [1], one by Percy ([2]) and one, soon to come, by Aerts et al. [3]. There have also been two excellent and detailed reviews by Gautschy and Saio ([4], [5]) about a decade ago. With the advent of Charge-Coupled Devices (CCDs) and large scale surveys like the Optical Gravitational Lensing Experiment (OGLE), the Massive Compact Halo Object project (MACHO) or the "Exp´eriencepour la Recherche d'Objets Sombres" (EROS), the subject of variable star studies is now under a remarkable expansion. As we will see the expansion will continue in the coming decade because there are many future projects which will sample frequently large regions of the sky.
    [Show full text]
  • Cluster Ages Experiment. CCD Photometry of SX Phoenicis Variables in the Globular Cluster M 55
    A&A 367, 148–158 (2001) Astronomy DOI: 10.1051/0004-6361:20000349 & c ESO 2001 Astrophysics Cluster AgeS Experiment. CCD photometry of SX Phoenicis variables in the globular cluster M 55 W. Pych1,J.Kaluzny1,W.Krzeminski1,2, A. Schwarzenberg-Czerny1,3, and I. B. Thompson2 1 Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warszawa, Poland 2 Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101, USA 3 Astronomical Observatory of Adam Mickiewicz University, ul. Sloneczna 36, 60-286 Poznan, Poland Received 28 June 2000 / Accepted 27 November 2000 Abstract. We present CCD photometry of SX Phe variables in the field of the globular cluster M 55. We have discovered 27 variables, three of which are probable members of the Sagittarius dwarf galaxy. All of the SX Phe stars in M 55 lie in the blue straggler region of the cluster color-magnitude diagram. Using period ratio information we have identified the radial pulsation modes for one of the observed variables. Inspection of the period-luminosity distribution permits the probable identifications of the pulsation modes for most of the rest of the stars in the sample. We have determined the slope of the period-luminosity relation for SX Phe stars in M 55 pulsating in the fundamental mode. Using this relation and the HIPPARCOS data for SX Phe itself, we have estimated the apparent distance modulus to M 55 to be (m − M)V =13.86 0.25 mag. Key words. globular clusters: individual: M 55 – (stars): blue stragglers: stars: variables: δ Sct – stars: oscillations – stars: population II 1.
    [Show full text]
  • Discrete Scale Relativity and Sx Phoenicis Variable Stars
    DISCRETE SCALE RELATIVITY AND SX PHOENICIS VARIABLE STARS Robert L. Oldershaw 12 Emily Lane Amherst, MA 01002 USA [email protected] Abstract: Discrete Scale Relativity proposes a new symmetry principle called discrete cosmological self-similarity which relates each class of systems and phenomena on a given Scale of nature’s discrete cosmological hierarchy to the equivalent class of analogue systems and phenomena on any other Scale. The new symmetry principle can be understood in terms of discrete scale invariance involving the spatial, temporal and dynamic parameters of all systems and phenomena. This new paradigm predicts a rigorous discrete self-similarity between Stellar Scale variable stars and Atomic Scale excited atoms undergoing energy-level transitions and sub- threshold oscillations. Previously, methods for demonstrating and testing the proposed symmetry principle have been applied to RR Lyrae, δ Scuti and ZZ Ceti variable stars. In the present paper we apply the same analytical methods and diagnostic tests to a new class of variable stars: SX Phoenicis variables. Double-mode pulsators are shown to provide an especially useful means of testing the uniqueness and rigor of the conceptual principles and discrete self-similar scaling of Discrete Scale Relativity. 1 I. Introduction a. Preliminary discussion of discrete cosmological self-similarity The arguments presented below are based on the Self-Similar Cosmological Paradigm (SSCP)1- 6 which has been developed over a period of more than 30 years, and can be unambiguously tested via its definitive predictions 1,4 concerning the nature of the galactic dark matter. Briefly, the discrete self-similar paradigm focuses on nature’s fundamental organizational principles and symmetries, emphasizing nature’s intrinsic hierarchical organization of systems from the smallest observable subatomic particles to the largest observable superclusters of galaxies.
    [Show full text]
  • The Variable Celestial Objects Detected by Gaia and Their Data Platform
    The variable celestial objects detected by Gaia and their data platform Laurent Eyer, Krzysztof Nienartowicz, CU7/DPCG Department of Astronomy, University of Geneva & CU5, DPAC Consortium Monday, 27 June 2019 The variable celestial objects detected by Gaia and their data platform Laurent Eyer, Krzysztof Nienartowicz, CU7/DPCG Department of Astronomy, University of Geneva & CU5, DPAC Consortium Monday, 27 June 2019 Introduction Introduction Large surveys Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Exo-planet / asterosismology from space Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Exo-planet / asterosismology from space CoRoT, K2/Kepler, TESS, MOST, BRITE, CHEOPS Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Exo-planet / asterosismology from space CoRoT, K2/Kepler, TESS, MOST, BRITE, CHEOPS Ground based projects Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Exo-planet / asterosismology from space CoRoT, K2/Kepler, TESS, MOST, BRITE, CHEOPS Ground based projects ASAS-SN, ASAS, HAT, HATPI, SuperWasp, … Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Exo-planet / asterosismology from space CoRoT, K2/Kepler, TESS, MOST, BRITE, CHEOPS Ground based projects ASAS-SN, ASAS, HAT, HATPI, SuperWasp, … Ground based telescopes for follow-ups Introduction Large surveys Gaia, LSST, ZTF, OGLE, Catalina, PanSTARRS … Exo-planet / asterosismology from space
    [Show full text]
  • SX Phoenicis Stars Suzanne Shuda Faculty Advisor: Dr
    SX Phoenicis Stars Suzanne Shuda Faculty Advisor: Dr. Oluseyi, Dept of Physics and Space Sciences, Florida Institute of Technology Introduction Methods and Design Results SX Phoenicis stars are usually found in I crossmatched the SDSS and SIMBAD A total of 42 SX Phoenicis stars were the outer regions of the galaxy which is databases to compile a list of likely SX found with metallicity measurements, called galactic halo. Their luminosity Phoenicis stars. I used SQL queries to much more than the previously known varies with a period of 1-2 hours. They display the information I wanted. I used 13 SX Phe stars. An O-C diagram are interesting because they are very old known characteristics such as spectral describes the observed minus but have not become white dwarfs as type and period to narrow down the stars calculated luminosity of a specific star. expected. Fewer than 20 field SX in the database. I learned the best queries The purpose is to study the long term Phoenicis stars are known to exist. By by experimenting with the suggestions in changes in luminosity. CY Aquarii, one studying these stars, we can learn about the tutorials on the website for SDSS. of the more well-known SX Phe stars how they formed, the makeup of the Using the data list from the SDSS which has been studied in the past. An galactic halo, and possibly locate dwarf Database, I crossmatched the list with the O-C diagram for CY Aquarii is shown in galaxies. The origin of SX Phe stars is SIMBAD database using the internal Fig 2.
    [Show full text]
  • Arxiv:1804.09382V2 [Astro-Ph.SR] 16 Apr 2020 R
    Astronomy & Astrophysics manuscript no. GaiaCons_EyerEtAl c ESO 2020 April 17, 2020 Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram Gaia Collaboration, L. Eyer1, L. Rimoldini2, M. Audard1, R.I. Anderson3; 1, K. Nienartowicz2, F. Glass1, O. Marchal4, M. Grenon1, N. Mowlavi1, B. Holl1, G. Clementini5, C. Aerts6; 7, T. Mazeh8, D.W. Evans9, L. Szabados10, A.G.A. Brown11, A. Vallenari12, T. Prusti13, J.H.J. de Bruijne13, C. Babusiaux4; 14, C.A.L. Bailer-Jones15, M. Biermann16, F. Jansen17, C. Jordi18, S.A. Klioner19, U. Lammers20, L. Lindegren21, X. Luri18, F. Mignard22, C. Panem23, D. Pourbaix24; 25, S. Randich26, P. Sartoretti4, H.I. Siddiqui27, C. Soubiran28, F. van Leeuwen9, N.A. Walton9, F. Arenou4, U. Bastian16, M. Cropper29, R. Drimmel30, D. Katz4, M.G. Lattanzi30, J. Bakker20, C. Cacciari5, J. Castañeda18, L. Chaoul23, N. Cheek31, F. De Angeli9, C. Fabricius18, R. Guerra20, E. Masana18, R. Messineo32, P. Panuzzo4, J. Portell18, M. Riello9, G.M. Seabroke29, P. Tanga22, F. Thévenin22, G. Gracia-Abril33; 16, G. Comoretto27, M. Garcia-Reinaldos20, D. Teyssier27, M. Altmann16; 34, R. Andrae15, I. Bellas-Velidis35, K. Benson29, J. Berthier36, R. Blomme37, P. Burgess9, G. Busso9, B. Carry22; 36, A. Cellino30, M. Clotet18, O. Creevey22, M. Davidson38, J. De Ridder6, L. Delchambre39, A. Dell’Oro26, C. Ducourant28, J. Fernández-Hernández40, M. Fouesneau15, Y. Frémat37, L. Galluccio22, M. García-Torres41, J. González-Núñez31; 42, J.J. González-Vidal18, E. Gosset39; 25, L.P. Guy2; 43, J.-L. Halbwachs44, N.C. Hambly38, D.L. Harrison9; 45, J. Hernández20, D. Hestroffer36, S.T. Hodgkin9, A. Hutton46, G.
    [Show full text]
  • A Summary of the Different Classes of Stellar Pulsators
    A Summary of the Different Classes of Stellar Pulsators A summary of all the classes of pulsating stars and their main properties as described in Chapter 2 is given in the tables below. This list originated from a combination of observational discoveries, measured stellar properties, and theoretical developments. Observers who found a new type of pulsator either named it after the prototype or gave the class a name according to the ob- served characteristics of the oscillations. Several pulsators, or even groups of pulsators, were afterwards found to originate from the same physical mech- anism and were thus merged into one and the same class. We sort this out here in Tables A.1 and A.2 in order to avoid further confusion on pulsating star nomenclature. The effective temperature and luminosity indicated in Tables A.1 and A.2 should be taken as rough indications only of the borders of instability strips. Often the theory is not sufficiently refined to consider these boundaries as final. Moreover, there is overlap between various classes where so-called hy- brid pulsators, whose oscillations are excited in two different layers and/or by two different mechanisms, occur. Finally, new discoveries are being made frequently, which then drive new theoretical developments possibly leading to new instability regions. The results from the future observing facilities as described in Chapter 8 will surely lead to new classes and/or subclasses with lower amplitudes compared to what is presently achievable. In the tables below, F stands for fundamental radial mode, FO for first radial overtone and S for strange mode oscillations.
    [Show full text]
  • Stars Variability
    Status: 14.08.19 Conference Information & Presentations Stars and their Variability observed from space Celebrating the birthday of BRITE-Constellation August 19 to 23, 2019 https://starsandspace.univie.ac.at/ Content 1. FLASHLIGHTS as INTRODUCTION ...................................................... 1 1i01 - The space photometry revolution .................................................................................................................. 1 1i02 - The demystification of classical Be stars through space photometry ............................................................ 1 1i03 - Listening to the Heartbeat: Tidal Asteroseismology in Action ....................................................................... 1 1i04 - From no-go to highlights: Red Giants ........................................................................................................... 1 1i05 - An innovative distance determination technique: ripples of light ................................................................... 2 1i06 - Nova Carinae 2018 - a first in many respects ............................................................................................... 2 2. PARAMETER SPACE & PATTERN ....................................................... 3 2k01 - GAIA's revolution in stellar variability ........................................................................................................... 3 2k02 - What we can learn from constant stars, and what means constant? ..........................................................
    [Show full text]
  • The First View of Δ Scuti and Γ Doradus Stars with the TESS Mission
    MNRAS 490, 4040–4059 (2019) doi:10.1093/mnras/stz2787 Advance Access publication 2019 October 7 The first view of δ Scuti and γ Doradus stars with the TESS mission V. Antoci ,1‹ M. S. Cunha,2 D. M. Bowman,3 S. J. Murphy,1,4 D. W. Kurtz,5 T. R. Bedding ,1,4 C. C. Borre,1 S. Christophe,6 J. Daszynska-Daszkiewicz,´ 7 Downloaded from https://academic.oup.com/mnras/article-abstract/490/3/4040/5583021 by Universidad de Granada - Biblioteca user on 23 March 2020 L. Fox-Machado,8 A. Garc´ıa Hernandez´ ,9,10 H. Ghasemi ,11 R. Handberg ,1 H. Hansen,1 A. Hasanzadeh,12 G. Houdek ,1 C. Johnston ,3 A. B. Justesen ,1 F. Kahraman Alicavus ,13,14 K. Kotysz,7 D. Latham,15 J. M. Matthews,16 J. Mønster,1 E. Niemczura,7 E. Paunzen ,17 J. P. Sanchez´ Arias,18 A. Pigulski,7 J. Pepper,19 T. Richey-Yowell,19,20 H. Safari ,12 S. Seager,21,22,23 B. Smalley ,24 T. Shutt,25 A. Sodor,´ 26,27 J.-C. Suarez´ ,9,10 A. Tkachenko,3 T. Wu ,28,29,30 K. Zwintz,31 S. Barcelo´ Forteza,32 E. Brunsden,25 Z. Bognar,´ 26,27 D. L. Buzasi,33 S. Chowdhury,13 P. De Cat,34 J. A. Evans,24 Z. Guo,13,35 J. A. Guzik,36 N. Jevtic,37 P. Lampens,34 M. Lares Martiz,10 C. Lovekin,38 G. Li,4 G. M. Mirouh,39 D. Mkrtichian,40 M. J. P. F. G. Monteiro,2,41 J.
    [Show full text]