Pulsating stars with the Pulsating stars with the

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Pulsating stars with the Pulsating stars with the

Transiting Exoplanet Survey Transiting Exoplanet Survey

Satellite (TESS) Satellite (TESS)

Peter De Cat Peter De Cat

Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium

Chairs of TASC working groups

Victoria Antoci (Denmark), Thierry Appourchaux (France), Sarbani Basu (USA), Bill Chaplin (UK), Stephane Charpinet (France), Margarida Cunha (Portugal), Gerald Handler (Poland),

Saskia Hekker (Germany), JJ Hermes (USA), Daniel Huber (USA), Katrien Kolenberg (Belgium), Victor Silva Aguirre (Denmark), Dennis Stello (Australia), Robert Szabo (Hungary)

(2)

1. 1. TESS as Space Mission TESS as Space Mission

3. 3. TESS and First Light Results TESS and First Light Results 2. 2. TESS and Pulsating stars TESS and Pulsating stars

Pulsating stars with TESS

(3)

Mission objectives Mission objectives

●

photometric all-sky survey to search for photometric all-sky survey to search for planets transiting nearby bright stars

planets transiting nearby bright stars

➢ 85% of sky85% of sky

➢ at least 200,000 main-sequence dwarf stars within 200 parsecat least 200,000 main-sequence dwarf stars within 200 parsec

➢ planets smaller than Neptuneplanets smaller than Neptune

➢ Cousins I-bandCousins I-band I ICC ≈ 4 − 13 mag to allow spectroscopic follow-up ≈ 4 − 13 mag to allow spectroscopic follow-up

✗ planet massesplanet masses

✗ atmospheric compositionsatmospheric compositions

1. TESS as Space Mission

●

variable stars of all types and flavors variable stars of all types and flavors

launch:

launch: April 18, 2018 April 18, 2018 orbit:

orbit: 13.7 day elliptical high-Earth orbit 13.7 day elliptical high-Earth orbit science operations:

science operations: July 25, 2018 July 25, 2018 duration:

duration: 2-year prime mission 2-year prime mission

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Telescope Telescope

●

four identical wide-field refractive cameras four identical wide-field refractive cameras

➢ single camera field-of-view: single camera field-of-view: 24°24° x 24 x 24°°

➢ combined field-of-view:combined field-of-view: 24° x 9624° x 96°°

➢ entrance pupil diameter:entrance pupil diameter: 10.5 cm10.5 cm

➢ focal ratio:focal ratio: f/1.4f/1.4

➢ wavelength range:wavelength range: 600-1000 nm600-1000 nm

➢ pixel size: 21 arcsec or 0.35 arcmin on skypixel size: 21 arcsec or 0.35 arcmin on sky

large pixels large pixels

sectors

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Operations Operations

●

field-of-view field-of-view

➔

26 observation sectors 26 observation sectors

➢ year 1: 13 southern hemisphereyear 1: 13 southern hemisphere

➢ year 2: 13 northern hemisphereyear 2: 13 northern hemisphere

➔

27 days each 27 days each

now now

sector 17 sector 17 orbit 41 orbit 41

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Operations Operations

●

field-of-view field-of-view

●

sky coverage sky coverage

➔

min. 27 days min. 27 days

➔

max. 351 days max. 351 days

➢ contains continuous contains continuous viewing zone of James viewing zone of James Webb Space Telescope Webb Space Telescope (JWST)

(JWST)

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Operations Operations

●

field-of-view field-of-view

●

sky coverage sky coverage

●

time sampling time sampling

➔

continuous full frame integrations of 2 seconds continuous full frame integrations of 2 seconds

➢ 30-minute cadence: 30-minute cadence: summed in groups of 900summed in groups of 900 full frames, all starsfull frames, all stars

➢ 2-minute cadence: 2-minute cadence: summed in groups of 60summed in groups of 60

extracted, pre-selected targetsextracted, pre-selected targets

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1. 1. TESS as Space Mission TESS as Space Mission

3. 3. TESS and First Light Results TESS and First Light Results 2. 2. TESS and Pulsating stars TESS and Pulsating stars

Pulsating stars with TESS

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TESS Asteroseismic Science Consortium TESS Asteroseismic Science Consortium

2. TESS and Pulsating stars

➢ WG-1: Asteroseismology of TESS exoplanet hostsWG-1: Asteroseismology of TESS exoplanet hosts

✗ Bill Chaplin & Daniel HuberBill Chaplin & Daniel Huber

➢ WG-2: Oscillations in solar-type starsWG-2: Oscillations in solar-type stars

✗ Thierry Appourchaux & Bill ChaplinThierry Appourchaux & Bill Chaplin

➢ WG-3: Oscillating stars in clustersWG-3: Oscillating stars in clusters

✗ Sarbani Basu & Saskia HekkerSarbani Basu & Saskia Hekker

➢ WG-4: Main Sequence AF "classical" pulsatorsWG-4: Main Sequence AF "classical" pulsators

✗ Victoria Antoci & Margarida CunhaVictoria Antoci & Margarida Cunha

➢ WG-5: Main Sequence OB "classical" pulsatorsWG-5: Main Sequence OB "classical" pulsators

✗ Peter De Cat & Gerald HandlerPeter De Cat & Gerald Handler

➢ WG-6: RR Lyrae stars and CepheidsWG-6: RR Lyrae stars and Cepheids

✗ Katrien Kolenberg & Róbert SzabóKatrien Kolenberg & Róbert Szabó

➢ WG-7: Red Giant oscillationsWG-7: Red Giant oscillations

✗ Victor Silva Aguirre & Dennis StelloVictor Silva Aguirre & Dennis Stello

➢ WG-8: CoWG-8: Compact pulsatorsmpact pulsators

Stephane Charpinet & JJ Hermes Stephane Charpinet & JJ Hermes

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TESS Asteroseismic Science Consortium TESS Asteroseismic Science Consortium

2. TESS and Pulsating stars

➢ WG-1:WG-1: Asteroseismology of TESS exoplanet hosts Asteroseismology of TESS exoplanet hosts

✗ Bill Chaplin & Daniel HuberBill Chaplin & Daniel Huber

➢ WG-2: Oscillations in solar-type starsWG-2: Oscillations in solar-type stars

✗ Thierry Appourchaux & Bill ChaplinThierry Appourchaux & Bill Chaplin

➢ WG-3:WG-3: Oscillating stars in clusters Oscillating stars in clusters

✗ Sarbani Basu & Saskia HekkerSarbani Basu & Saskia Hekker

➢ WG-4: Main Sequence AF "classical" pulsatorsWG-4: Main Sequence AF "classical" pulsators

✗ Victoria Antoci & Margarida CunhaVictoria Antoci & Margarida Cunha

➢ WG-5: Main Sequence OB "classical" pulsatorsWG-5: Main Sequence OB "classical" pulsators

✗ Peter De Cat & Gerald HandlerPeter De Cat & Gerald Handler

➢ WG-6:WG-6: RR Lyrae stars and Cepheids RR Lyrae stars and Cepheids

✗ Katrien Kolenberg & Róbert SzabóKatrien Kolenberg & Róbert Szabó

➢ WG-7: Red Giant oscillationsWG-7: Red Giant oscillations

✗ Victor Silva Aguirre & Dennis StelloVictor Silva Aguirre & Dennis Stello

➢ WG-8:WG-8: Compact pulsators Compact pulsators

✗ Stephane Charpinet & JJ HermesStephane Charpinet & JJ Hermes

Selection of 2-min cadence targets Selection of 2-min cadence targets

Stimulation of collaborations

Coördination of publications

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1. 1. TESS as Space Mission TESS as Space Mission

3. 3. TESS and First Light Results TESS and First Light Results 2. 2. TESS and Pulsating stars TESS and Pulsating stars

Pulsating stars with TESS

(12)

WG-1:

WG-1: Asteroseismology of TESS exoplanet hosts Asteroseismology of TESS exoplanet hosts

3. TESS and First Light Results

(Chairs: Bill Chaplin & Daniel Huber)

➔

all all types of pulsating stars types of pulsating stars

➢ characterisation of host stars of exoplanets by characterisation of host stars of exoplanets by using asteroseismic techniques

using asteroseismic techniques

(13)

➢ Huber et al., 2019, AJ, 157, 245: "A Hot Saturn Orbiting an Oscillating Late Subgiant Huber et al., 2019, AJ, 157, 245: "A Hot Saturn Orbiting an Oscillating Late Subgiant Discovered by TESS"

Discovered by TESS"

➢ Campante et al., 2019, ApJ, accepted: "Tess asteroseismology of the known red-giant host Campante et al., 2019, ApJ, accepted: "Tess asteroseismology of the known red-giant host stars HD212771 and HD203949"

stars HD212771 and HD203949"

➢ Lund et al., 2019, ApJ, submitted: "Asteroseismology of the multi-planet system K2-93"Lund et al., 2019, ApJ, submitted: "Asteroseismology of the multi-planet system K2-93"

➢ Campante et al., 2019, proceedings of PHOST (Physics of Oscillating Stars): "Synergy Campante et al., 2019, proceedings of PHOST (Physics of Oscillating Stars): "Synergy between asteroseismology and exoplanet science: an outlook"

between asteroseismology and exoplanet science: an outlook"

WG-1:

WG-1: Asteroseismology of TESS exoplanet hosts Asteroseismology of TESS exoplanet hosts

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WG-1:

WG-1: Asteroseismology of TESS exoplanet hosts Asteroseismology of TESS exoplanet hosts

➔

Detection of transiting planet Detection of transiting planet orbiting oscillating host star

orbiting oscillating host star

➢ bright starbright star (V = 8.2 mag) (V = 8.2 mag)

➢ clear signature of eclipse and mixed modesclear signature of eclipse and mixed modes

➢ oscillation amplitude consistent with oscillation amplitude consistent with KeplerKepler

➢ asteroseismic modelling host starasteroseismic modelling host star

✗ RR^star^star = 2.936(61) R = 2.936(61) R^sun^sun

✗ MM^star^star = 1.198(81) M = 1.198(81) M^sun^sun

✗ age = 5.04(126) Gyrage = 5.04(126) Gyr subgiantsubgiant

(Huber et al., 2019, AJ, 157, 245)

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WG-1:

WG-1: Asteroseismology of TESS exoplanet hosts Asteroseismology of TESS exoplanet hosts

➔

Detection of transiting planet Detection of transiting planet orbiting oscillating host star

orbiting oscillating host star

➢ bright starbright star (V = 8.2 mag) (V = 8.2 mag)

➢ clear signature of eclipse and mixed modesclear signature of eclipse and mixed modes

➢ oscillation amplitude consistent with oscillation amplitude consistent with KeplerKepler

➢ asteroseismic modelling host starasteroseismic modelling host star

✗ RR^star^star = 2.936(61) R = 2.936(61) R^sun^sun

✗ MM^star^star = 1.198(81) M = 1.198(81) M^sun^sun

✗ age = 5.04(126) Gyrage = 5.04(126) Gyr

➢ planet characterisationplanet characterisation

✗ MMplanetplanet = 0.191(17) M = 0.191(17) MJupiterJupiter

✗ planetplanet = 0.424(60) gcm = 0.424(60) gcm^-3^-3

subgiant subgiant

hot Saturn hot Saturn

one of the most precisely characterized one of the most precisely characterized

Saturn-sized planets to date Saturn-sized planets to date

(Huber et al., 2019, AJ, 157, 245)

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WG-2:

WG-2: Oscillations in solar-type stars Oscillations in solar-type stars

(Chairs: Thierry Appourchaux & Bill Chaplin)

➔

solar-like oscillations solar-like oscillations

(Solar-like)(Solar-like)

➢ order of minutesorder of minutes (p/mixed-modes) (p/mixed-modes)

➢ short-livedshort-lived (bell-shaped frequency distribution) (bell-shaped frequency distribution)

➢ scaling relationsscaling relations

✗  ~ sqrt(M/R ~ sqrt(M/R³³)) (large frequency spacing) (large frequency spacing)

✗ max_max ~ g/sqrt(T ~ g/sqrt(T^ef^ef)) (frequency of maximum power) (frequency of maximum power)

→ mass and radius→ mass and radius

➢ fitting of individual frequencies in échelle diagramfitting of individual frequencies in échelle diagram

(Huber et al., 2019, AJ, 157, 245)

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➢ Bugnet et al., 2019, AA, 624, A79: "FliPer_Class: In search of solar-like pulsators among Bugnet et al., 2019, AA, 624, A79: "FliPer_Class: In search of solar-like pulsators among TESS targets"

TESS targets"

➢ Schofield et al., 2019, ApJS, 241, 12: "The Asteroseismic Target List for Solar-like Schofield et al., 2019, ApJS, 241, 12: "The Asteroseismic Target List for Solar-like

Oscillators Observed in 2 minute Cadence with the Transiting Exoplanet Survey Satellite"

➢ Chaplin et al., 2019, submitted: "Age dating of an early Milky Way merger via Chaplin et al., 2019, submitted: "Age dating of an early Milky Way merger via asteroseismology of the naked-eye star ν Indi"

asteroseismology of the naked-eye star ν Indi"

WG-2:

WG-2: Oscillations in solar-type stars Oscillations in solar-type stars

TESS: progress from TESS: progress from

* combination with ground-based follow-up data

* statistical studies

- - detection of solar-like oscillations detection of solar-like oscillations - understanding of evolved systems with- understanding of evolved systems with

planetsplanets

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WG-3:

WG-3: Oscillating stars in clusters Oscillating stars in clusters

(Chairs: Sarbani Basu & Saskia Hekker)

➔

all types of pulsating stars all types of pulsating stars

TESS not ideal for this type of research:

* large pixel size

* large pixel size (contamination) (contamination)

* main-sequence stars in clusters are faint

* lack of clusters in fields with long time-base

(19)

WG-4:

WG-4: Main sequence AF “classical” pulsators Main sequence AF “classical” pulsators

(Chairs: Victoria Antoci & Margarida Cunha)

➔

  Scuti stars Scuti stars

⁽⁽^^^Sct)^Sct)

➢ 1 - 5 hours1 - 5 hours (p-modes) (p-modes)

➔

  Doradus stars Doradus stars

⁽⁽^^^Dor)^Dor)

➢ 0.3 – 3 days0.3 – 3 days (g-modes) (g-modes)

➔

rapidly oscillating Ap stars rapidly oscillating Ap stars

^(roAp)^(roAp)

➢ 5 – 25 minutes5 – 25 minutes (p-modes) (p-modes)

➢ chemically peculiarchemically peculiar

➢ magnetic fieldmagnetic field

➔

magnetic magnetic A-type A-type stars stars

➔

pre-main sequence pre-main sequence

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WG-4:

WG-4: Main sequence AF “classical” pulsators Main sequence AF “classical” pulsators

➢ Cunha et al., 2019, MNRAS, 487, 3523: "Rotation and pulsation in Ap stars: first light Cunha et al., 2019, MNRAS, 487, 3523: "Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2"

results from TESS sectors 1 and 2"

➢ David-Uraz et al., 2019, MNRAS, 487, 304: David-Uraz et al., 2019, MNRAS, 487, 304: "Magnetic OB[A] Stars with TESS: probing their "Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of known magnetic Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of known magnetic B and A stars"

B and A stars"

➢ Balona, 2019, MNRAS, 487, 2117: Balona, 2019, MNRAS, 487, 2117: "High frequencies in TESS A–F main-sequence stars""High frequencies in TESS A–F main-sequence stars"

➢ Sikora et al., 2019, MNRAS, 487, 4695: Sikora et al., 2019, MNRAS, 487, 4695: "MOBSTER – II. Identification of rotationally variable "MOBSTER – II. Identification of rotationally variable A stars observed with TESS in sectors 1–4"

A stars observed with TESS in sectors 1–4"

➢ Holdsworth et al., 2019, MNRAS, 489, 4063: Holdsworth et al., 2019, MNRAS, 489, 4063: "HD42659: the only known roAp star in a "HD42659: the only known roAp star in a spectroscopic binary observed with B photometry, TESS, and SALT"

spectroscopic binary observed with B photometry, TESS, and SALT"

➢ Antoci et al., 2019, MNRAS, accepted: Antoci et al., 2019, MNRAS, accepted: "The first view of δ Scuti and γ Doradus stars with the "The first view of δ Scuti and γ Doradus stars with the TESS mission"

TESS mission"

➢ Khalack, 2019, MNRAS, accepted: Khalack, 2019, MNRAS, accepted: "Rotational and pulsational variability in the TESS light "Rotational and pulsational variability in the TESS light curve of HD27463"

curve of HD27463"

➢ Bowman et al., 2019, ApJL, accepted: Bowman et al., 2019, ApJL, accepted: "Discovery of tidally-perturbed pulsations in the "Discovery of tidally-perturbed pulsations in the eclipsing binary U Gru: a pioneering system for tidal asteroseismology"

eclipsing binary U Gru: a pioneering system for tidal asteroseismology"

➢ Bedding et al., 2019, submitted: Bedding et al., 2019, submitted: "Regular sequences of pulsation overtones in young "Regular sequences of pulsation overtones in young intermediate-mass stars"

intermediate-mass stars"

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WG-4:

WG-4: Main sequence AF “classical” pulsators Main sequence AF “classical” pulsators

➔

Rotation and pulsation in Ap stars: first Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2

light results from TESS sectors 1 and 2

➢ analysis of 2-min cadence data of 83 starsanalysis of 2-min cadence data of 83 stars

➢ detection of detection of

✗ 5 new roAp stars 5 new roAp stars (4 multiperiodic + 4 rotational mode splitting)

(4 multiperiodic + 4 rotational mode splitting)

✗ shortest pulsation period roAp star known to date shortest pulsation period roAp star known to date (4.68 min; frequency 3.563 mHz)(4.68 min; frequency 3.563 mHz)

✗ additional oscillation modes in some starsadditional oscillation modes in some stars

✗ true pulsation modes from aliases in ground-based datatrue pulsation modes from aliases in ground-based data

✗ rotation periods for 27 rotational variables rotation periods for 27 rotational variables

(10 improved values; shortest rotation period roAp star known to date: 5.855 days) (10 improved values; shortest rotation period roAp star known to date: 5.855 days)

➢ constraints on constraints on ii and magnetic obliquity for 4 stars and magnetic obliquity for 4 stars (application oblique pulsator model) (application oblique pulsator model)

➢ confirmation of absence of pulsations down to 6/13 confirmation of absence of pulsations down to 6/13 ^^mag for 2 known noAp starsmag for 2 known noAp stars

➢ amplitudes in TESS filter factor 6 smaller than amplitudes in amplitudes in TESS filter factor 6 smaller than amplitudes in BB filter from ground filter from ground

confirmation of potential of TESS for study of roAp stars confirmation of potential of TESS for study of roAp stars

(Cunha et al., 2019, MNRAS, 487, 3523)

(22)

WG-4:

WG-4: Main sequence AF “classical” pulsators Main sequence AF “classical” pulsators

➢ Cunha et al., 2019, MNRAS, 487, 3523: "Rotation and pulsation in Ap stars: first light Cunha et al., 2019, MNRAS, 487, 3523: "Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2"

results from TESS sectors 1 and 2"

➢ David-Uraz et al., 2019, MNRAS, 487, 304: David-Uraz et al., 2019, MNRAS, 487, 304: "Magnetic OB[A] Stars with TESS: probing their "Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of known magnetic Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of known magnetic B and A stars"

B and A stars"

➢ Balona, 2019, MNRAS, 487, 2117: Balona, 2019, MNRAS, 487, 2117: "High frequencies in TESS A–F main-sequence stars""High frequencies in TESS A–F main-sequence stars"

➢ Sikora et al., 2019, MNRAS, 487, 4695: Sikora et al., 2019, MNRAS, 487, 4695: "MOBSTER – II. Identification of rotationally variable "MOBSTER – II. Identification of rotationally variable A stars observed with TESS in sectors 1–4"

A stars observed with TESS in sectors 1–4"

➢ Holdsworth et al., 2019, MNRAS, 489, 4063: Holdsworth et al., 2019, MNRAS, 489, 4063: "HD42659: the only known roAp star in a "HD42659: the only known roAp star in a spectroscopic binary observed with B photometry, TESS, and SALT"

spectroscopic binary observed with B photometry, TESS, and SALT"

➢ Antoci et al., 2019, MNRAS, accepted: Antoci et al., 2019, MNRAS, accepted: "The first view of δ Scuti and γ Doradus stars with the "The first view of δ Scuti and γ Doradus stars with the TESS mission"

TESS mission"

➢ Khalack, 2019, MNRAS, accepted: Khalack, 2019, MNRAS, accepted: "Rotational and pulsational variability in the TESS light "Rotational and pulsational variability in the TESS light curve of HD27463"

curve of HD27463"

➢ Bowman et al., 2019, ApJL, accepted: Bowman et al., 2019, ApJL, accepted: "Discovery of tidally-perturbed pulsations in the "Discovery of tidally-perturbed pulsations in the eclipsing binary U Gru: a pioneering system for tidal asteroseismology"

eclipsing binary U Gru: a pioneering system for tidal asteroseismology"

➢ Bedding et al., 2019, submitted: Bedding et al., 2019, submitted: "Regular sequences of pulsation overtones in young "Regular sequences of pulsation overtones in young intermediate-mass stars"

intermediate-mass stars"

(23)

WG-4:

WG-4: Main sequence AF “classical” pulsators Main sequence AF “classical” pulsators

(Antoci et al., 2019, MNRAS, accepted)

➔

First view of First view of   Sct and Sct and   Dor stars with TESS Dor stars with TESS

➢ 2-min cadence data of 117 stars, incl.2-min cadence data of 117 stars, incl.

✗  Doradus Doradus

✗ SX PhoenicisSX Phoenicis

➢ confrontation theoretical models of pulsation driving confrontation theoretical models of pulsation driving

✗ time-dependent non-local convection treatmenttime-dependent non-local convection treatment

✗ mimicking He depletion in outer envelopemimicking He depletion in outer envelope

➢ ratio of amplitude in TESS to Kepler about 74%ratio of amplitude in TESS to Kepler about 74%

turbulent pressure plays important role turbulent pressure plays important role

explanation for driving in Am stars explanation for driving in Am stars strongest driving in center of classical strongest driving in center of classical

instability strip

(~7500K)(~7500K)

(24)

WG-5:

WG-5: Main sequence OB “classical” pulsators Main sequence OB “classical” pulsators

(Chairs: Peter De Cat & Gerald Handler)

➔

  Cephei stars Cephei stars

⁽⁽^^^Cep)^Cep)

➢ 2 – 7 hours2 – 7 hours (p/g-modes) (p/g-modes)

➔

Slowly Pulsating B stars Slowly Pulsating B stars

^(SPB)^(SPB)

➢ 0.3 – 3 days0.3 – 3 days (g-modes) (g-modes)

➔

Periodically Variable Supergiants Periodically Variable Supergiants

^(PVSG)^(PVSG)

➢ 10 – 100 days10 – 100 days (internal gravity waves) (internal gravity waves)

➔

Be stars Be stars

(rapid rotation, episodes of H (rapid rotation, episodes of H^^ emission) emission)

➔

magnetic magnetic OB-type OB-type stars stars

➔

pre-main sequence pre-main sequence

lack of space-based studies lack of space-based studies

for OB-type stars

(25)

➢ Pedersen et al., 2019, ApJL, 872, L9: "Diverse Variability of O and B Stars Revealed Pedersen et al., 2019, ApJL, 872, L9: "Diverse Variability of O and B Stars Revealed from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection of an Asteroseismic Sample"

of an Asteroseismic Sample"

➢ Handler et al., 2019, ApJL, 873, L4: "Asteroseismology of Massive Stars with the TESS Handler et al., 2019, ApJL, 873, L4: "Asteroseismology of Massive Stars with the TESS Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr"

Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr"

➢ Balona et al., 2019, MNRAS, 485, 3457: "Rotational modulation in TESS B stars"Balona et al., 2019, MNRAS, 485, 3457: "Rotational modulation in TESS B stars"

➢ David-Uraz et al., 2019, MNRAS, 487, 304: "Magnetic OB[A] Stars with TESS: probing David-Uraz et al., 2019, MNRAS, 487, 304: "Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of their Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of known magnetic B and A stars"

known magnetic B and A stars"

➢ Shultz et al., 2019, MNRAS, submitted: "MOBSTER - III. HD 62658, the second Shultz et al., 2019, MNRAS, submitted: "MOBSTER - III. HD 62658, the second magnetic chemically peculiar eclipsing binary"

magnetic chemically peculiar eclipsing binary"

➢ Wade et al., 2019, MNRAS, submitted: "Evolving pulsation of the slowly rotating Wade et al., 2019, MNRAS, submitted: "Evolving pulsation of the slowly rotating magnetic β Cep star ξ^1 CMa"

magnetic β Cep star ξ^1 CMa"

WG-5:

WG-5: Main sequence OB “classical” pulsators Main sequence OB “classical” pulsators

(26)

WG-5:

WG-5: Main sequence OB “classical” pulsators Main sequence OB “classical” pulsators

➔

Diverse variability of O and B stars Diverse variability of O and B stars

➢ analysis of 2-min cadence data of analysis of 2-min cadence data of 154 OB-type stars

154 OB-type stars

➢ detection of variability in 90% of objects:detection of variability in 90% of objects:

✗ 23 multiperiodic pulsators23 multiperiodic pulsators

✗ 6 eclipsing binaries6 eclipsing binaries

✗ 21 rotational variables21 rotational variables

✗ 25 stars with stochastic low-frequency 25 stars with stochastic low-frequency variability

variability

✗ variables with overlap in categoriesvariables with overlap in categories

✗ hybrid pulsatorshybrid pulsators

selection of sample of OB-type stars with selection of sample of OB-type stars with

high potential for asteroseismic + high potential for asteroseismic + spectroscopic modelling of interior spectroscopic modelling of interior structure with unprecedented precision structure with unprecedented precision

(Pedersen et al., 2019, ApJL 872, 9)

(27)

➢ Pedersen et al., 2019, ApJL, 872, L9: "Diverse Variability of O and B Stars Revealed Pedersen et al., 2019, ApJL, 872, L9: "Diverse Variability of O and B Stars Revealed from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection of an Asteroseismic Sample"

of an Asteroseismic Sample"

➢ Handler et al., 2019, ApJL, 873, L4: "Asteroseismology of Massive Stars with the TESS Handler et al., 2019, ApJL, 873, L4: "Asteroseismology of Massive Stars with the TESS Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr"

Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr"

➢ Balona et al., 2019, MNRAS, 485, 3457: "Rotational modulation in TESS B stars"Balona et al., 2019, MNRAS, 485, 3457: "Rotational modulation in TESS B stars"

➢ David-Uraz et al., 2019, MNRAS, 487, 304: "Magnetic OB[A] Stars with TESS: probing David-Uraz et al., 2019, MNRAS, 487, 304: "Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of their Evolutionary and Rotational properties (MOBSTER) – I. First-light observations of known magnetic B and A stars"

known magnetic B and A stars"

➢ Shultz et al., 2019, MNRAS, submitted: "MOBSTER - III. HD 62658, the second Shultz et al., 2019, MNRAS, submitted: "MOBSTER - III. HD 62658, the second magnetic chemically peculiar eclipsing binary"

magnetic chemically peculiar eclipsing binary"

➢ Wade et al., 2019, MNRAS, submitted: "Evolving pulsation of the slowly rotating Wade et al., 2019, MNRAS, submitted: "Evolving pulsation of the slowly rotating magnetic β Cep star ξ^1 CMa"

magnetic β Cep star ξ^1 CMa"

WG-5:

WG-5: Main sequence OB “classical” pulsators Main sequence OB “classical” pulsators

(28)

WG-5:

WG-5: Main sequence OB “classical” pulsators Main sequence OB “classical” pulsators

➔

Runaway Runaway ^ ^ Cep pulsator PHL346 = HN Aqr Cep pulsator PHL346 = HN Aqr

➢ previously known as single-periodic pulsatorpreviously known as single-periodic pulsator

➢ detection ofdetection of

✗ at least 34 oscillation modesat least 34 oscillation modes (12 g-mode, 22 p-modes) (12 g-mode, 22 p-modes)

✗ amplitude & frequency variability of dominant modeamplitude & frequency variability of dominant mode

✗ long-term radial velocity variationslong-term radial velocity variations

✗ age constraint of 23(1) Myrage constraint of 23(1) Myr (kinematic analysis) (kinematic analysis)

→ → not compatible with first attempts of not compatible with first attempts of

asteroseismic modellingasteroseismic modelling

accurate age determination of runaway accurate age determination of runaway pulsators can become vital in tracing the pulsators can become vital in tracing the

evolutionary history of these objects evolutionary history of these objects

(Handler et al., 2019, ApJL 873, 4)

(29)

WG-6:

WG-6: RR Lyrae stars and Cepeids RR Lyrae stars and Cepeids

(Chairs: Katrien Kolenberg & Róbert Szabó)

➔

RR Lyrae stars RR Lyrae stars

^{(RR Lyrae)}^{(RR Lyrae)}

➢ RRab variables: RRab variables: 0.3 – 1 days0.3 – 1 days (fundamental F) (fundamental F)

➢ RRc variables: RRc variables: 0.2 – 0.5 days0.2 – 0.5 days (first-overtone 1O) (first-overtone 1O)

➢ RRd variables: RRd variables: 0.2 – 1 days0.2 – 1 days (F+1O) (F+1O)

➔

Cepheids Cepheids

➢ classical Cepheidsclassical Cepheids

✗ F:F: 1 – 200 days 1 – 200 days

✗ 1O:1O: 0.24 – 8 days0.24 – 8 days

➢ Type II CepheidsType II Cepheids

✗ BL Her:BL Her: 1 – 5 days1 – 5 days

✗ W Vir: W Vir: 4 – 20 days4 – 20 days

✗ RV Tau:RV Tau: 40 – 100 days40 – 100 days

➢ anomalous Cepheidsanomalous Cepheids

✗ F: F: 0.1 – 2 days0.1 – 2 days

(30)

WG-6:

WG-6: RR Lyrae stars and Cepeids RR Lyrae stars and Cepeids

(Plachy, Molnár et al., 2019, in preparation)

➔

Light curves of handful Cepheid and ~hundred RR Lyrae stars Light curves of handful Cepheid and ~hundred RR Lyrae stars

➢ RRa variable RRa variable (fundamental mode)(fundamental mode) with unusually strong additional mode with unusually strong additional mode

✗ first radial overtone outside the classical double-mode regime?first radial overtone outside the classical double-mode regime?

✗ non-radial mode with a similar period?non-radial mode with a similar period?

→→ suitable for mode identification from southern telescopessuitable for mode identification from southern telescopes

(31)

WG-6:

WG-6: RR Lyrae stars and Cepeids RR Lyrae stars and Cepeids

(Plachy, Molnár et al., 2019, in preparation)

➔

Light curves of handful Cepheid and ~hundred RR Lyrae stars Light curves of handful Cepheid and ~hundred RR Lyrae stars

➢ RRa variable RRa variable (fundamental mode)(fundamental mode) with unusually strong additional mode with unusually strong additional mode

✗ first radial overtone outside the classical double-mode regime?first radial overtone outside the classical double-mode regime?

✗ non-radial mode with a similar period?non-radial mode with a similar period?

→→ suitable for mode identification from southern telescopessuitable for mode identification from southern telescopes

➢ diference of distribution for additional modes in RRc variables diference of distribution for additional modes in RRc variables (first-overtone)(first-overtone) between between

✗ region near Sun observed by TESSregion near Sun observed by TESS

✗ region in Galactic bulge observed by OGLEregion in Galactic bulge observed by OGLE

→→ due to diferences in composition between field and bulge RR Lyrae stars?due to diferences in composition between field and bulge RR Lyrae stars?

selection bias in TESS sample?

TESS

TESS expected to have large impact on serveral topics expected to have large impact on serveral topics

, e.g., e.g.

* proper classification of subtypes for short period Cepheids and RR Lyrae stars

* statistical study of occurrence of additional modes

* statistical study of occurrence of additional modes (understanding of mode selection) (understanding of mode selection), , nonlinear efects, light curve stability, etc. nonlinear efects, light curve stability, etc.

(32)

WG-7:

WG-7: Red giant oscillators Red giant oscillators

(Chairs: Victor Silva Aguirre & Dennis Stello)

➔

red giant stars red giant stars

^(RG)^(RG)

➢ 1 hour – 4 days1 hour – 4 days (solar-like, mixed-modes) (solar-like, mixed-modes)

➢ distinguish red giants burning helium in cores distinguish red giants burning helium in cores from those still only burning hydrogen in a shell from those still only burning hydrogen in a shell

(Bedding et al., 2011, Nature 471, 608)

(33)

➢ Campante et al., 2019, ApJ, accepted: "Tess asteroseismology of the known red-giant host Campante et al., 2019, ApJ, accepted: "Tess asteroseismology of the known red-giant host stars HD212771 and HD203949"

stars HD212771 and HD203949"

➢ Pereira et al., 2019, MNRAS, accepted: "Gaussian Process modelling of granulation and Pereira et al., 2019, MNRAS, accepted: "Gaussian Process modelling of granulation and oscillations in red-giant stars"

oscillations in red-giant stars"

WG-7:

WG-7: Red giant oscillators Red giant oscillators

(34)

➔

TESS asteroseismology of known host stars TESS asteroseismology of known host stars

➢ HD212771HD212771 (G8IV; T=6.75) (G8IV; T=6.75)

✗ Juvian planetJuvian planet (M (MPPsini = 2.3(4) Msini = 2.3(4) MJJ))

✗ orbit of 373.3 daysorbit of 373.3 days

➢ stellar parameters stellar parameters (T(Tefef, [Fe/H]), [Fe/H]) and abundances from high-resolution spectroscopy and abundances from high-resolution spectroscopy

➢ constraints on stellar radii and luminosity constraints on stellar radii and luminosity (L(L_*_*)) from spectral energy distribution fitting from spectral energy distribution fitting

(broadband photometry) (broadband photometry)

➢ first detection of oscillations with TESS for red-giant planet host stars first detection of oscillations with TESS for red-giant planet host stars ^(⁽^^{, }^,^^max^max⁾⁾

(Campante et al., 2019, ApJ, submitted)

WG-7:

WG-7: Red giant oscillators Red giant oscillators

➢ HD203949HD203949 (K2III; T=4.75) (K2III; T=4.75)

✗ massive planetmassive planet^(M^(M^P^Psini = 8.2(2) Msini = 8.2(2) MJJ))

(35)

➔

TESS asteroseismology of known host stars TESS asteroseismology of known host stars

➢ HD212771HD212771 (G8IV; T=6.75) (G8IV; T=6.75)

WG-7:

WG-7: Red giant oscillators Red giant oscillators

➢ HD203949HD203949 (K2III; T=4.75) (K2III; T=4.75)

grid-based grid-based modelling modelling approach approach

, , _max_max, [Fe/H],, [Fe/H], TTefef, L, L_*_*

 MM_*_*, R, R_*_*, , _*_*,,

logglogg, age, age

“retired A star”“retired A star” H-shell burning (RGB)?H-shell burning (RGB)?

He-core burning (RC)?

frequency resolution too frequency resolution too low for determination of low for determination of

period spacing

period spacing  

(36)

➔

TESS asteroseismology of known host stars TESS asteroseismology of known host stars

➢ HD212771HD212771 (G8IV; T=6.75) (G8IV; T=6.75)

➢ ratio of amplitude TESS to K2: 75(14)% ratio of amplitude TESS to K2: 75(14)%

WG-7:

WG-7: Red giant oscillators Red giant oscillators

➢ HD203949HD203949 (K2III; T=4.75) (K2III; T=4.75)

TESS: revision of properties of stellar population surrounding Sun TESS: revision of properties of stellar population surrounding Sun

* asteroseismology of red giants

* in unbiased way

* to a much larger volume than before (~3000 parsec)

(37)

WG-8:

WG-8: Compact pulsators Compact pulsators

➔

sub-dwarf B variables sub-dwarf B variables

^(sdBV)^(sdBV)

➢ sdBVsdBV^r^r: 90 - 600 sec: 90 - 600 sec^(p-modes)^(p-modes)

➢ sdBVsdBV^s^s: 1 - 4 hours: 1 - 4 hours (g-modes) (g-modes)

➢ sdBVsdBVrsrs: both regimes: both regimes

➔

pulsating pre-white dwarfs pulsating pre-white dwarfs

➢ GW Virginis stars GW Virginis stars (GW Vir): (GW Vir): 5 – 85 min 5 – 85 min (g-modes)(g-modes)

➔

pulsating white dwarfs pulsating white dwarfs

➢ DBV stars: DBV stars:

200 – 1000 sec

200 – 1000 sec (g-modes) (g-modes)

➢ DAV stars: DAV stars:

100 –1500 sec

100 –1500 sec (g-modes) (g-modes)

(Chairs: Stéphane Charpinet & JJ Hermes)

(38)

➢ Charpinet et al., 2019, A&A, submitted: "TESS first look at evolved compact pulsators: Charpinet et al., 2019, A&A, submitted: "TESS first look at evolved compact pulsators:

Discovery and asteroseismic probing of the g-mode hot B subdwarf pulsator Discovery and asteroseismic probing of the g-mode hot B subdwarf pulsator TIC278659026"

TIC278659026"

➢ Bell et al., 2019, RNAAS, 3, 81: "A Hot Subdwarf B Star Eclipsed by a Low-mass White Bell et al., 2019, RNAAS, 3, 81: "A Hot Subdwarf B Star Eclipsed by a Low-mass White Dwarf in TESS Data"

Dwarf in TESS Data"

➢ Bell et al., 2019, A&A, submitted: "TESS first look at evolved compact pulsators: Bell et al., 2019, A&A, submitted: "TESS first look at evolved compact pulsators:

"Asteroseismology of the pulsating helium-atmosphere white dwarf TIC257459955"

➢ Althaus et al., 2019, A&A, submitted: "On the existence of warm H-rich pulsating white Althaus et al., 2019, A&A, submitted: "On the existence of warm H-rich pulsating white dwarfs"

dwarfs"

➢ Reed et al., 2019, MNRAS, TASC review: "TESS observations of the interesting pulsating Reed et al., 2019, MNRAS, TASC review: "TESS observations of the interesting pulsating subdwarf B star CDS-28 1974"

subdwarf B star CDS-28 1974"

WG-8:

WG-8: Compact pulsators Compact pulsators

(39)

WG-8:

WG-8: Compact pulsators Compact pulsators

(Charpinet et al. 2019, A&A, submitted)

➔

Discovery and asteroseismic probing of g-mode hot B subdwarf Discovery and asteroseismic probing of g-mode hot B subdwarf pulsator

pulsator

(based on analysis of 2-min data in sector 1) (based on analysis of 2-min data in sector 1)

➢ rich frequency spectrum between 96 – 605 rich frequency spectrum between 96 – 605 ^^Hz Hz (27 – 174 min; incl. 20 independent g-modes)(27 – 174 min; incl. 20 independent g-modes)

(40)

WG-8:

WG-8: Compact pulsators Compact pulsators

➔

Discovery and asteroseismic probing of g-mode hot B subdwarf Discovery and asteroseismic probing of g-mode hot B subdwarf pulsator

pulsator

➢ asteroseismic modelling asteroseismic modelling in agreement with frequencies, atmospheric parameters, and astrometryin agreement with frequencies, atmospheric parameters, and astrometry

✗ M = 0.391(9) MM = 0.391(9) M^sun^sun (low) (low) → progenitor red giant, not undergone He-core flash?→ progenitor red giant, not undergone He-core flash?

✗ He-rich envelope mass = 0.0037(10) MHe-rich envelope mass = 0.0037(10) M^sun^sun

✗ R = 0.1694(81) RR = 0.1694(81) R^sun^sun

✗ L = 8.2(11) LL = 8.2(11) L^sun^sun

✗ internal chemical stratification: double-layered He/H composite profileinternal chemical stratification: double-layered He/H composite profile

→ ongoing gravitational settling of He at bottom of thick H-rich envelope→ ongoing gravitational settling of He at bottom of thick H-rich envelope

✗ core: core: → 43% in mass of central He burnt→ 43% in mass of central He burnt

→ M→ M^core^core = 0.198(10) M = 0.198(10) M^sun^sun (relatively large mixed core)(relatively large mixed core)

→ X→ X(O)(O)^core^core = 0.16(+13/-5) in mass produced by He-burning core = 0.16(+13/-5) in mass produced by He-burning core

constraints for studies of

¹²¹²

C( C( ^ ^ , , ^ ^ ) )

¹⁶¹⁶

O nuclear reaction rate O nuclear reaction rate

(41)

WG-8:

WG-8: Compact pulsators Compact pulsators

➔

Discovery and asteroseismic probing of g-mode hot B subdwarf Discovery and asteroseismic probing of g-mode hot B subdwarf pulsator

pulsator

➢ asteroseismic modelling asteroseismic modelling in agreement with frequencies, atmospheric parameters, and astrometryin agreement with frequencies, atmospheric parameters, and astrometry

✗ M = 0.391(9) MM = 0.391(9) M^sun^sun (low) (low) → progenitor red giant, not undergone He-core flash?→ progenitor red giant, not undergone He-core flash?

✗ He-rich envelope mass = 0.0037(10) MHe-rich envelope mass = 0.0037(10) M^sun^sun

✗ R = 0.1694(81) RR = 0.1694(81) R^sun^sun

✗ L = 8.2(11) LL = 8.2(11) L^sun^sun

✗ internal chemical stratification: double-layered He/H composite profileinternal chemical stratification: double-layered He/H composite profile

→ ongoing gravitational settling of He at bottom of thick H-rich envelope→ ongoing gravitational settling of He at bottom of thick H-rich envelope

✗ core: core: → 43% in mass of central He burnt→ 43% in mass of central He burnt

→ M→ M^core^core = 0.198(10) M = 0.198(10) M^sun^sun (relatively large mixed core)(relatively large mixed core)

→ X→ X(O)(O)^core^core = 0.16(+13/-5) in mass produced by He-burning core = 0.16(+13/-5) in mass produced by He-burning core

constraints for studies of

¹²¹²

C( C( ^ ^ , , ^ ^ ) )

¹⁶¹⁶

O nuclear reaction rate O nuclear reaction rate

TESS will have an enormous impact on the field of TESS will have an enormous impact on the field of compact pulsators given the large number of stars compact pulsators given the large number of stars

ultimately monitored

(42)

Conclusions and future prospects Conclusions and future prospects

Best prospects for Best prospects for

* statistical studies

* variables with short enough periods

➔

Advantages of TESS for many classes of pulsating stars Advantages of TESS for many classes of pulsating stars

➢ accurate photometry with either 30 min or 2 min cadenceaccurate photometry with either 30 min or 2 min cadence

➢ for many targets given that 85% of the sky will be observedfor many targets given that 85% of the sky will be observed

➢ including bright objects allowing ground-based follow-up for characterizationincluding bright objects allowing ground-based follow-up for characterization

➔

Disadvantages of TESS for some classes of pulsating stars Disadvantages of TESS for some classes of pulsating stars

➢ contamination problems due to large pixel sizecontamination problems due to large pixel size

➢ sectors observed for 27 dayssectors observed for 27 days

➔

Importance of ground-based data Importance of ground-based data

➢ extension of time-base of observationsextension of time-base of observations

➢ characterisation of the starscharacterisation of the stars

Thank you!