BUT DOES IT QUACK LIKE A DUCK? STARS IN CLUSTERS. Andrea Miglio, Karsten Brogaard, Rasmus Handberg

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1 LOOKS LIKE A DUCK, MOVES LIKE A DUCK, BUT DOES IT QUACK LIKE A DUCK? ASTEROSEISMOLOGY OF RED-GIANT STARS IN CLUSTERS Andrea Miglio, Karsten Brogaard, Rasmus Hberg School of Physics Astronomy, University of Birmingham, UK STELLAR ASTROPHYSICS CENTRE Aarhus University, Denmark

2 13.5 SOLAR-LIKE OSCILLATIONS 16 V V e+4 15 KIC e+4 KIC e e NGC L/Lsun B V Power spectral density Power spectral density [ppm /µhz][ppm /µhz] 6.e+4 KIC KIC e+4 2.e KIC e+5 KIC e e ννmax max B V 5.e+4 6 Figure 1. CMD of NGC 6791 (left-h panel) NGC 6819 (right-h panel). Photometric are taken from Stetson, Hole et al. (29), respectively. RGB stars used in this work are marked by open squares RC stars by openkiccircles. See Sec target selection. KIC NGC6 4 Kepler KASC stars Kepler Objects of Interest 2.e e+5 1.e Teff [K] e+4 6 KIC et al. 1991; Kjeldsen & Bedding 1995; Mosser et al. 21; Belkacem et al. 211), refore Chaplin & Miglio, ARAA, νmax M/M! νmax,, 2 (R/R ) Teff /Teff, whereetνal.max, Brown 1991 = 31 µhz T eff, = 5777 K. Kjeldsen&Bedding 1995relations Belkacem al. 211 used to estimate These scaling are etwidely 5 (2) masses radii of red giants (see e.g. Stello et al. 28; Kallinger et al. 21; Frequency [µhz] 2 alone (see equations 5 6, respective ing to a mass estimate with no explici equation 7): " #2 " #3/2 " "ν L Teff M M "ν L Teff, Frequency [µhz] M " νmax #" L #" Teff #

3 SOLAR-LIKE OSCILLATIONS.12.1 = 2 R R dr 1/ c(r) M/R 3 1/2.8 m 2 s 2 µhz ν [µhz] BiSON Davies et al. 214

4 NON-RADIAL MODES IN K GIANTS gravity mode acoustic mode He core H-burning shell H-rich radiative core convective envelope

5 The in photometric time( t series presented here obtained long cadence 3 min, Jenkins et al. were (21a)) tained long 3 min, Jenkins et al. were (21a)) The in photometric series presented here obbetween 29 cadence May time 12 ( t 21 March 2, known as obbetween 29 cadence May 21 March 2, known as obtained inquarters long ( t 3 min, Jenkins et al. serving (Q1 Q4). Within this period (21a)) spaceserving quarters (Q1 Q4). Within this2, period 14, spacebetweenlong-cadence 29 May provided 21 March known as obcraft s mode approximately craft s long-cadence mode approximately points per star. rawprovided images by serving quarters 1 4 The (Q1 Q4). Withinwere this processed period 14, spacesun points per star. The rawprovided images processed by stard Kepler Science Pipeline were included steps 14, to recraft s long-cadence mode approximately stard Kepler Science Pipeline included steps to remove signatures in sources such as pointing points per star. The rawfrom images were processed by move signatures in from sources such as pointing drifts, focus changes, rmal variations all steps performed stard Kepler Science Pipeline included to redrifts, focus changes, variations all asperformed during Pre-search Data Conditioning (PDC) procedure move signatures in rmal from sources such pointing during Pre-search Datarmal Conditioning procedure (Jenkins et al. 21b). PDC also corrects for(pdc) fluxallfrom neighdrifts, focus changes, variations performed (Jenkins et al. 21b).each PDC also correctsaperture for(pdc) flux based from neighboring within photometric on a during stars Pre-search Data Conditioning procedure boring stars photometric aperture based on a static aperture model.each However, this model is not adequate (Jenkins et al.within 21b). PDC also corrects for flux from neighstatic model. However, thisinmodel is not adequate for allaperture stars, due to each small changes telescope pointboring stars within photometric aperture based on a sun for allaperture stars, due to pointing small changes telescope pointspread-function between subsequent static model. However, thisinmodel is not quarterly adequate spread-function between rolls when spacecraft rotated 9 degrees to quarterly align its for all stars,due to pointing smallischanges in subsequent telescope pointrolls when is rotated 9subsequent degrees to quarterly align its solar panels.asspacecraft a result curves show jumps in spread-function pointing between solar panels. Asspacecraft a from resultone curves show in average flux level to9 next.jumps Toalign correct rolls when is quarter rotated degrees to its for we average flux levels for each average fluxshifted level one to show next. To quarter correct solarthat panels. As a from result quarter curves jumps in for that we flux levels for each to match thatshifted of from rawaverage (pre-pdc) before stitching toaverage flux level one quarter to next. To quarter correct ger time from all fourflux quarters. This ensured that to that ofseries raw (pre-pdc) before stitching toformatch thatwe shifted average levels for each quarter relative flux variations were consistent from one quarter ger that time from(pre-pdc) all four quarters. This stitching ensured that to match ofseries raw before toto next. We compared our corrected (post-pdc) with relative flux variations were consistent from one quarter ger time series from all four quarters. This ensured that raw We compared also afterour we performed a number of manto next. corrected (post-pdc) with relative flux variations were consistent from one quarter ual corrections based entirely on appearance of man raw We compared also after wecorrected performed a number of to next. our (post-pdc) with sun curves (hence notbased taking auxiliary such as ual corrections entirely on house-keeping appearance of of raw also after we performed a number manpointing into account). These corrections included curves (hence notbased takingentirely auxiliary house-keeping such as ual corrections on appearance of removal of outliers, jumps, slow trends in a similar way asremoval pointing into account). These corrections included curves (hence not taking auxiliary house-keeping suchapas proach by Garcia et al. (211). The comparison revealed that of outliers, jumps, slow trends in a similar way as appointing into account). These corrections included removal for a few PDC didslow not trends perform well, in which we proach bystars Garcia et al. (211). Theincomparison revealed of outliers, jumps, a similar way ascase that apchose raw or manually corrected raw. for a few stars PDC did not perform well, in which case we proach by Garcia et al. (211). The comparison revealed that chose raw manually raw. for a few starsorpdc did not corrected perform well, in which case we 4. BLENDING AND LIGHT CURVE VERIFICATION chose raw or manually corrected raw. 4. BLENDING AND LIGHT The super stamps in Figure 1 CURVE clearlyverification illustrate that blend4. BLENDING AND LIGHT CURVE VERIFICATION ingthe is an issue we need to address before proceeding with super stamps in Figure 1 clearly illustrate that blendthe analysis of se. Some stars show clear ing is an issue we need to address before proceeding with super stamps incluster Figure 1 clearly illustrate that blendsignatures of of blending arising from relatively large pixel se cluster. Some stars show clear ing analysis is an issue we need to address before proceeding with scale ( 4 ) of Kepler photometer compared to fairly signatures of of blending arising. from relatively large pixel analysis se cluster Some stars show clear crowded fields. Blending willgive rise totolarge additional scale ( 4cluster ) of Kepler photometer compared fairly signatures of blending arising from relatively pixel sun in photometric aperture, which will reduce relacrowded cluster fields. Blending will give rise to additional scale ( 4 ) of Kepler photometer compared to fairly tive stellar variability, increasewhich photon counting in photometric aperture, willrise reduce noise. relacrowded cluster fields.blending will give to additional In severe detected stellar variability arises from a tive stellar variability, aperture, increase photon counting noise. in cases, photometric which will reduce relablending notdetected In cases, stellar variability arises from tivesevere stellarstar variability, target. increase photon counting noise.a have studied from variability blending by looking blending star not effects target. InWe severe cases, detected stellar arises fromata correlations between curvesfrom of allblending targetbystars (black, We have looking at blending starstudied not effects target. red, purple, blue dots in Figure 2). The curve correcorrelations between curvesfrom of allblending targetbystars (black, We have studied effects looking at lations show no significant increase unless stars are within red, purple, blue dots in Figure 2). The curve correcorrelations between curves of all target stars (black, acoustic spectrum of a R~1 R star ~8 Gyr ~2.5 Gyr ~1 Gyr ν~ 35 μhz M~ 1.1 M ν~ 55 μhz M~ 1.6 M ν~ 8 μhz M~ 2.5 M

6 SOUNDING K GIANTS IN CLUSTERS overmassive undermassive

7 OVERMASSIVE STARS Hole et al. photometry RGB stars used in this study RC stars used in this study Overmassive stars 13 Masses ~ 2-3 MSUN detection V in depth studies of ir structure e.g. internal rotational profile, core structure NGC6819 compare with expectations from binary evolution B V Hberg et al. 215, in preparation Brogaard et al. 215

8 .7 RC A LI-RICH 1.6 M SUN RGB STAR Anthony-Twarog et al. 213 Carlberg et al. 215 Rosvick & VenBerg 1998 *

9 EXPLOITING ENSEMBLES Stetson et al. photometry RGB stars used in this study RC stars used in this study Hole et al. photometry RGB stars used in this study RC stars used in this study Stello et al. 21,211 Basu et al. 211 Hekker et al. 211 Miglio et al. 212 Corsaro et al V V NGC NGC [Fe/H]~ [Fe/H]~ B V B V

10 INTEGRATED RGB MASS LOSS NGC6791 q Mass(RGB) vs Mass(RC) RGB RC M/M sun V Miglio et al. 212 quantitative estimate of integrated RGB mass loss V M =.9±.3 (rom) ±.4 (systematic) M SUN

11 TESTING HECB MODELS bare-schwarzschild 1Hp overshooting 1Hp penetrative convection Bossini, et al., 215 Vrad, et al., in preparation Arentoft, et al., in preparation Bossini, et al., in preparation

12 ACOUSTIC GLITCHES IN GIANTS Kepler giants in NGC KIC ν fit = µhz l= l=1 l= KIC ν fit = µhz l= l=1 l=2 4.1 ν (µhz) ν (µhz) KIC ν fit = µhz l= l=1 l= Frequency (µhz) Frequency (µhz) 3.2 Hberg, et al, in preparation ν (µhz) Frequency (µhz)

13 ANY HOPE FOR SEISMOLOGY IN GCS?

14 ANY HOPE FOR SEISMOLOGY IN GCS? M4: a first glimpse K2P 2 pipeline, Lund et al. 215 Miglio, Chaplin, Brogaard, et al. in preparation

15 ANY HOPE FOR SEISMOLOGY IN GCS? M4: a first glimpse ν max M/M (R/R ) 2 T eff /T eff, ν max, where = 31 Hz T ν max Observed [µhz] ν max Expected [µhz] V 15 Cluster members Detections 7 6 ' q M R ν Observed [µhz] V I Miglio, Chaplin, Brogaard, et al. in preparation ν Expected [µhz]

16 SUMMARY asteroseismology of K giants in clusters: exposing camouflage: overmassive stars undermassive Li-rich RC star age-mass relations mass loss, mass loss dispersion testing stellar models first look at M4 with K2: detection of solar-like oscillations