Ground Based Photometry

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Ground Based Photometry. S.O. Kepler Brazil. Photometry. Single Channel Two channel: star + comparison Three channel: star+comparison+sky CCD: star + comparisons + skies g-modes in Earths atmosphere diffraction rings. CCD. Flat field SNR=1000 : 100 flats at 1% linearity - PowerPoint PPT Presentation

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  • S.O. KeplerBrazil

  • PhotometrySingle ChannelTwo channel: star + comparisonThree channel: star+comparison+skyCCD: star + comparisons + skiesg-modes in Earths atmospherediffraction rings

  • CCDFlat field SNR=1000 : 100 flats at 1% linearityAt least 2 comparisons stars, brightAutoguideFrame transfer or low duty cycle or windowingPrecise timingsQuantum efficiency and altitude variation affect Amp.

  • SX Phe, Rodriguez et al.

  • Data reductionTimings for barycenter of the solar systemLeap second correctionsExtinction correctionOptimum extraction: aperture vs seeing

  • MultiperiodicHerbig Ae star, Bernabel et al.

  • Fourier TransformsNoise not poissonicData not equally spacedNeed Monte Carlo simulation for false alarm probabilityIdentification of multiple modes: pre-whitening

  • 2.1m4.1mFrequency

  • Low amplitude pulsators

  • DistanceParallax 95 + 37 pcOptical Spectra 58 + 02 pcIUE flux 59 + 05 pcHST flux 67 + 04 pcSeismology Bradley 1998 61pcSeismology Benvenutto et al. 2002 63 pcMean: 67 + 14 pc215s270s304s107s119s125s

  • PG1336-018,Maia VuckovicVik Dhillon, Stuart Littlefair, and Paul Kerry (Sheffield, UK), Tom Marsh (Warwick, UK), Andy Vick and Dave Atkinson (UKATC, Edinburgh, UK)

  • STEPHI

    Date

    Object

    # freq

    Noise level

    Effective duration

    PI

    I

    06/87

    63 Her

    6

    .

    .

    J.A. Belmonte

    II

    08/89

    GX Peg

    5

    1.5 E-4

    219h

    E. Michel

    III

    11/90

    V650 Tau

    4

    7.6E-4

    167h

    E. Michel

    IV

    02/92

    BUCnc

    6

    7.6E-4 (3.E-4)

    228h

    J.A. belmonte

    .

    //

    BNCnc

    5

    7.6E-4 (2.E-4)

    //

    //

    V

    09/93

    VW Ari

    7

    6.E-4

    150h

    Liu Y.Y.

    VI

    02/95

    BQ Cnc

    9

    4.E-4 (1.7E-4)

    210h

    M. Alvarez

    .

    //

    BWCnc

    3

    //

    //

    //

    VII

    02/96

    BS Cnc

    3

    7.7E-4

    115h

    M. Hernandez

    .

    //

    BT Cnc

    2

    //

    //

    //

    VIII

    11/97

    V647 Tau

    5

    1.6E-4

    228h

    E. Michel

    IX

    11/98

    V534 Tau

    11

    2.5E-4

    286h

    Li Z.P.

    X

    12/99

    V624 Tau

    7

    3.0E-4

    269h

    L. Fox Machado

    .

    //

    HD23194

    2

    4.2E-4

    //

    //

    XI

    11/02

    HD23628

    .

    .

    .

    J. Pea

    .

    //

    HD23567

    .

    .

    .

    //

    XII

    06/03

    7 Aql

    .

    .

    .

    L. Fox Machado

    8 Aql

    //

    XIII

    06/04

    HD172189

    E. Michel

    XIV

    11/05

    in progress

    XV

    10/06

    in progress

  • DSN CampaignsDSN 1 Theta 2 Tauri 1983 DSN 2 4 CVn 1984 DSN 3 Theta 2 Tauri 1986 DSN 4 HR729 1988 DSN 5 BU Cnc & EP Cnc 1989 DSN 6 63 Her 1990 DSN 7 HN CMa 1990 DSN 8 CD -24 7599 1992 DSN 9 FG Vir 1993 DSN 10 IC 418 1993 DSN 11 CD -24 7599 1994 DSN 12 Theta 2 Tauri 1994 DSN 13 IC 418 1994 DSN 14 FG Vir 1995 DSN 15 4 CVn 1996 DSN 16 4 CVn 1997 DSN 17 CD -24 7599 1998 DSN 18 BI CMi 1998/1999 DSN 19 BI CMi 1999/2000 DSN 20 44 Tau 2000 DSN 21 44 Tau 2001 DSN 22 FG Vir 2002 DSN 23 FG Vir 2003 DSN 24 44 Tau 2003 DSN 25 FG Vir 2004, 79 freqsDSN 26 44 Tau 2004 DSN 27 HD210111 & ,AS Eri 2005 DSN 28 UV Oct & SS For 2005 DSN 29 44 Tau 2005

  • Whole Earth TelescopeXCov1 Mar 1988 *PG 1346+082* IBWD Winget, Provencal V803 Cen IBWD O'Donoghue XCov 2 Nov 1988 *G29-38* DAV Winget V471 Tau ICBS ClemensXCov 3 Mar 1989 *PG 1159-035* GW Vir WingetXCov 4 Mar 1990 *AM CVn* IBWD Solheim, Provencal G117-B15A DAV KeplerXCov 5 May 1990 *GD358* DBV Winget GD165 DAV Bergeron HD 166473 roAp KurtzXCov 6 May 1991 *PG 1707* GW Vir Clemens, Pfeiffer GD154 DAV VauclairXCov 7 Feb 1992 *1H0857* CV Buckley PG 1115 DBV Barstow, Clemens G226-29 DAV Kepler WET-0856 d Scu Breger, HandlerXCov 8 Sep 1992 *PG 2131+066* GW Vir Kawaler, Nather G185-32 DAV Moskalik RX J2117 GW Vir Vauclar, MoskalikXCov 9 Mar 1993 *PG 1159-035* GW Vir Winget *FG Vir* d Scu BregerXCov 10 May 1994 *GD358* DBV Nather, BradleyXCov 11 Aug 1994 *RX J2117* GW Vir Vauclar, MoskalikXCov 12 Apr 1995 *PG 1351* DBV Hansen L19-2 DAV Sullivan, ClemensXCov 13 Feb 1996 *RE 0751+14* CV Marar, Seetha CD-24 7599 d Scu Breger, HandlerXCov 14 Sep 1996 *PG 0122+200* GW Vir O'Brien WZ Sge CV Nather XCov 15 Jul 1997 *DQ Her* CV Nather EC 20058 DBV O'DonoghueXCov 16 May 1998 *BPM 37093* DAV Kanaan, KeplerXCov 17 Apr 1999 *PG 1336* sdB Kilkenny *BPM 37093* DAV Kanaan, Kepler, Nitta, WingetXCov 18 Nov 1999 *HL Tau 76* ZZ Ceti Dolez, Vauclair, Kleinman PG 0122 DOV Vauclair, O'BreinXCov 19 June 2000 *GD358* DBV Kepler, NittaXCov 20 Nov 2000 *HR 1217* roAp Kurtz KUV 05134+2605 DBV Handler, Nitta R 548 ZZ Ceti MukadamXCov 21 Apr 2001 *PG 1336* sdb Reed, Kilkenny PG 1654-160 DBV Handler Feige 48 sdB Reed, Kawaler Mrk 501 AGN Miller, KrennrichXcov 22 May 2002 *PG 1456+103* DBV Handler PG 1159-035 GW Vir O'Brein Feige 48 sdB Reed, Kawaler PG 1605+072 sdB Schuh, et. al, & MSSTXCov 23 Aug 2003 *KPD 1930+2752* sdB Charpinet, Reed G 29-38 DAV Kleinman HS 2201+2610 sdB SilvottiXCov 24 Oct 2004 *PG 0014* sdB Kawaler RX J2117 GW Vir MoskalikXCov 25 Jul 2006 GD358 DBV ProvencalXCOV 26 Mar 2008 EC14012-114 DAV Montgomery PG1159-035 DOV Costa

  • Don KurtzMargarida Cunha

  • k=14 - 42J. Edu S. CostaPG1159-035-no harmonics or combination modes-no convection zone- 198 modes: 29 triplets, 46 quintuplets

  • Period(s)PG1159-035DP=21.43+0.05sM=0.586+0.001MSun

  • Crsico et al. 2008

  • dP/dt=(+10.6+0.1)x10-11 s/sE(cycles)

  • Costa & Kepler 2008: rotation, contraction rates, cooling ratesdP/dtdPRotation/dtdR/dtdT/dt

  • ResultsdP/dt (516s)= 1ms/yr = (13.146+0.003)x10-11 s/s, (517s)=(15.172+0.045)x10-11s/s , (539s)=(-0.339+0.015)x10-11s/s

    d2P/dt2 =(1.93+0.08)x10-20 s/s, (517s)=(-81.7+2.7)+10-20 s/s

    Protation=1.3935+0.0008 ddProt/dt=(-2.13+0.05)x10-6 s/sdR/dt=(-2.8+0.2)x10-12 s/sdT/dt=(-7.6+0.2)x10-11 s/s

    Trapping at 0.83R*+0.05

    DP(l=1)=21.43+0.03s M=0.59+0.02 MSunDP(l=2)=12.38+0.01sB

  • Rotation effectsMultiplets have different amplitudes Amplitudes change (energy exchange with rotation?)Gough: Only when the star is rotating is there a physically real principal axis with a well defined directed orientation So if there is an m = +1 , m = 1 asymmetry it has to be a consequence of rotation.

  • ZZ Ceti white dwarf

  • Mike Montgomery

  • Hydrogen layer mass

  • White dwarf pulsationsPulsations are global and sample almost the whole interiors of white dwarf stars.The seismologically determined masses are more accurate than those obtained from binary solutions.Asteroseismology is the only tool to measure the surface layer masses, which are determined from the up-to-now not accurately modeled mass loss through stellar evolution.Asteroseismology can determine the core composition of white dwarf stars and help to measure the C( a,g)O reaction rate that cannot be measured in a terrestrial laboratory.Asteroseismology can accurately measure the nature and extent of surface partial ionization zones and probe convective energy transport.The rates of change of the pulsation periods are measurable and can be used to precisely measure the evolutionary rates of these old stars, to detect planets around them, and to probe for exotic particles that are strong candidates for dark matter.

  • Questions on mode properties

    What are the driving, mode selection, and amplitude limiting mechanism(s)? Are they the same for all strips and throughout each strip? What is the cause of the amplitude and phase changes on timescales from weeks to years? What is the origin, role, and nature of mode coupling? What is the role of inclination in m-selection, considering we see the amplitude of different m components change with time in a few stars?Can we measure the velocity and line profile variations needed for mode identification, necessary for full asteroseismic analysis? Are there other values of the spherical harmonic degree, besides 1 and 2 already observed in white dwarfs? High l have been identified in sd.Is driving different for different pulse shapes, or for the DOVs, where the models do not indicate significant convection?Can we identify the modes with chromatic amplitude and combination peaks?

  • *****