1 The Real Music of the Spheres Asteroseismology.

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The Real The Real

Music of the SpheresMusic of the Spheres

AsteroseismologyAsteroseismology

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Sir Arthur Stanley Eddington:The Internal Constitution of the Stars

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At first sight it would seem At first sight it would seem that the deep interior that the deep interior of the sun and stars of the sun and stars

is less accessible is less accessible to scientific investigation to scientific investigation

than any other region of the than any other region of the universe.universe.

Sir Arthur Eddington (1882 – 1944)

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Our telescopes may probe Our telescopes may probe farther and farther farther and farther

into the depths of space; into the depths of space; but how can we ever obtain but how can we ever obtain

certain knowledge certain knowledge of that which is hidden of that which is hidden

behind substantial barriers?behind substantial barriers?

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What appliance What appliance can pierce through can pierce through

the outer layers of a star the outer layers of a star and test and test

the conditions within?the conditions within?

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3D oscillations – stars3D oscillations – starsradial modesradial modes

CepheidsP1/P0= 0.7

stringP1/P0= 0.33

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Cepheid variablesCepheid variables

Cepheid Horn by Zoltan Kollath & Geza Kovács, Konkoly Observatory, Budapest; Robert Buchler, Florida

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A giant solar-like oscillatorA giant solar-like oscillator

http://www.lcse.umn.edu/

C:\Documents and Settings\dwk\My Documents\talks\Music of the Spheres\RedGiantBig.mov

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AsteroseismologyAsteroseismology

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Angular structure of the modesAngular structure of the modes

nn = = number of radial nodesnumber of radial nodes = = total number of surface nodestotal number of surface nodes mm = = number of surface nodes that are lines number of surface nodes that are lines

of longitudeof longitude – – m = m = number of surface nodes that are number of surface nodes that are

lines of latitudelines of latitude

immmm ePNY cos,

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Dipole modesDipole modes

immm ePY cos, 11

l=1, m=0 l=1, m=+1l=1, m=-1

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immm ePY cos, 22

l=2, m=-1l=2, m=-2 l=2, m=0

Quadrupole modesQuadrupole modes

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Rotation of the sunRotation of the sun

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p modes and g modesp modes and g modes

J. P. Cox, 1980, Theory of Stellar Pulsation, Princeton University Press.

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p modes and g modesp modes and g modes

p modes (n,) = (8,100), (8,2)

g mode (n,) = (10,5)

Gough et al., 1996, Science, 272, 1281

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The sun as a star - BiSONThe sun as a star - BiSON

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0 2n n

The sun as a star - GOLFThe sun as a star - GOLF

large separation small separation

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An asteroseismic HR diagramAn asteroseismic HR diagram

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Solar-like Oscillations in Solar-like Oscillations in Centauri Centauri

UVES & UCLESUVES & UCLES 42 oscillation frequencies42 oscillation frequencies ℓℓ = 1-3= 1-3 Mode lifetimes only Mode lifetimes only

1-2 days1-2 days Noise level = 2 cm sNoise level = 2 cm s-1-1!!

Bedding, T., et al. 2004, ApJ, 614, 380

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Modelling Modelling Cen A and B Cen A and B Stellar model in good agreement with the Stellar model in good agreement with the

astrometric, photometric, spectroscopic and astrometric, photometric, spectroscopic and asteroseismic data asteroseismic data

t = 6.52 ± 0.30 Gyrt = 6.52 ± 0.30 Gyr Initial Y = 0.275 ± 0.010 Initial Y = 0.275 ± 0.010 Initial Z/X = 0.043 ± 0.002Initial Z/X = 0.043 ± 0.002 Radii of both stars determined with Radii of both stars determined with

high precision (errors smaller than 0.3%)high precision (errors smaller than 0.3%) compatible with interferometric results of compatible with interferometric results of

Kervella et al. (differences smaller than 1%)Kervella et al. (differences smaller than 1%)

Eggenberger, P., Charbonnel, C., Talon, S., Meynet, G., Maeder, A., Carrier, F., Bourban, G. 2004, A&A, 417, 235

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Oscillations and planetsOscillations and planets Stellar activity, convection and pulsation are Stellar activity, convection and pulsation are

“noise” to planet-hunters“noise” to planet-hunters

Planets are “noise” to asteroseismologistsPlanets are “noise” to asteroseismologists

The two fields are not just complementaryThe two fields are not just complementary

It is mandatory to do both together atIt is mandatory to do both together atcm scm s-1-1 precision precision

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AraeArae

V = 5.15V = 5.15 G3IV-VG3IV-V

PProtrot = 22 days = 22 days

14 M14 M planet; P planet; Porborb = 9.55 days = 9.55 days

43 p-modes detected43 p-modes detected 8-day single-site HARPS study8-day single-site HARPS study

Bouchy, F., Bazot, M., Santos, N. C., Vauclair, S., Sosnowska, D., 2005, A&A, 440, 609

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Arae – the Arae – the 14 M14 M planet planet


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Arae – ~8-min pulsationsArae – ~8-min pulsations


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AraeArae


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Resolving pulsations Resolving pulsations

in the atmospheresin the atmospheres

of roAp starsof roAp stars

Don KurtzDon KurtzVladimir ElkinVladimir Elkin

Gautier MathysGautier Mathys

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Theoretical expectationTheoretical expectation

Saio, 2005, MNRAS, 360, 1022

= 0.7 = 0.1

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HD 101065HD 101065

BaII NdIII

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~ 10-5

~ 10-2

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HD99563HD99563

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~ 10-5

~ 10-2

~ 10-5

<< 10-5

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Gautschy, Saio & Harzenmoser, 1998, MNRAS, 301, 31

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HD154708HD154708

Hubrig, S., Nesvacil, N., Schöller, M., North, P., Mathys, G., Kurtz, D. W., Wolff, B., Szeifert, T., Cunha, M. S., Elkin, V. G., 2005, A&A, 440, L37

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HD154708HD154708

Kurtz, D. W., Elkin, V. G., Elkin, V. G., Mathys, G., Hubrig, Wolff, B., Savanov, I., 2006, MNRAS, submitted

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We are seeing the roAp staratmospheres

in more detail than is possiblefor any star

other than the sun

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White dwarfs – gWhite dwarfs – g--mode pulsatorsmode pulsators

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PG 1159-035

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TTsurfsurf = 123,000 - 124,000 K; log g = 123,000 - 124,000 K; log g 7 7

1000 1000 f f 2600 2600 Hz; 385 Hz; 385 P P 1000 1000

ss

125 frequencies; >100 modes125 frequencies; >100 modes

M = 0.586 ± 0.003 M = 0.586 ± 0.003 MM

the star is compositionally stratifiedthe star is compositionally stratified

PG 1159-035PG 1159-035

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BPM 37093BPM 37093 DAVDAV

M = 1.09 M = 1.09 MM

TTeffeff = 11730 K = 11730 K

Partially crystallized Partially crystallized

C-O coreC-O core

Metcalfe, T. S., Montgomery, M. H., Kanaan, A. 2004, ApJ, 605, 133

Kanaan et al., 2005, A&A, 432, 219

Brassard & Fontaine, 2005, ApJ, 622, 572

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BPM 37093BPM 37093

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p modes: EC 14026 stars - sdBVp modes: EC 14026 stars - sdBV

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PG 1336 + 018PG 1336 + 018

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p modes: p modes: Cephei stars Cephei stars

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HD 129929 = V836 Cen HD 129929 = V836 Cen 20-yr multicolour photometry

Core overshooting with aOV = 0.1

Non-rigid rotation: 4 times faster near core

Aerts et al., 2003, Science, 300, 926 Asteroseismology of HD129929: Core overshooting and nonrigid rotation

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g modes: SPB starsg modes: SPB stars

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Continuous coverage - MOSTContinuous coverage - MOST

HD163830 HD163830 SPB starSPB star V = 9.3V = 9.3 B5II/IIIB5II/III 37 days coverage37 days coverage 20 frequencies 20 frequencies

detecteddetected

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HD 163830HD 163830

Aerts, C.; De Cat, P.; Kuschnig, R.; Matthews, J. M.; Guenther, D. B.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.; Walker, G. A. H.; Weiss, W. W., 2006, ApJ, 642, L65

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HD 163830HD 163830

Aerts, C.; De Cat, P.; Kuschnig, R.; Matthews, J. M.; Guenther, D. B.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.; Walker, G. A. H.; Weiss, W. W., 2006, ApJ, 642, L65

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Dome C - ConcordiaDome C - Concordia

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Seeing 2003-2004: statisticsSeeing 2003-2004: statistics

0.100.10 Seeing minSeeing min0.540.54Median seeingMedian seeing

5.225.22 Seeing maxSeeing max0.650.65Mean seeing (arcsec)Mean seeing (arcsec)

0.390.39 Std deviationStd deviation1714817148N dataN data

1 30.30.1

50%

0.50.5

Seeing distribution (log-normal)

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What appliance What appliance can pierce through can pierce through

the outer layers of a star the outer layers of a star and test and test

the conditions within?the conditions within?

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Stellarmusicno1Stellar acoustics as input for music compositionStellar acoustics as input for music composition

Zoltán KolláthZoltán KolláthKonkoly Observatory, Budapest, HungaryKonkoly Observatory, Budapest, Hungary

Jenő KeulerJenő KeulerInstitute for Musicology, Budapest, HungaryInstitute for Musicology, Budapest, Hungary

http://www.konkoly.hu/staff/kollath/stellarmusic/

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Photometry - HR 1217 WET Xcov20Photometry - HR 1217 WET Xcov20

Kurtz et al., 2005, MNRAS, 358, 651

= 14 magprecision

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What can you do with the frequencies What can you do with the frequencies in roAp stars? – HR 1217in roAp stars? – HR 1217

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A model and predictionA model and prediction

Cunha, M. 1999, PhD thesis, CambridgeCunha, M. 1999, PhD thesis, CambridgeCunha, M. Gough, D., 2001, MNRAS, 319, 1020Cunha, M. Gough, D., 2001, MNRAS, 319, 1020Bigot et al. 2000, A&A, 356, 218Bigot et al. 2000, A&A, 356, 218

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HR 1217HR 1217photometric campaignsphotometric campaigns

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HR 1217HR 1217photometric campaignsphotometric campaigns

1 The Real Music of the Spheres Asteroseismology.

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