---
_id: '13443'
abstract:
- lang: eng
  text: 'The ages of solar-like stars have been at the center of many studies such
    as exoplanet characterization or Galactic-archeology. While ages are usually computed
    from stellar evolution models, relations linking ages to other stellar properties,
    such as rotation and magnetic activity, have been investigated. With the large
    catalog of 55,232 rotation periods, Prot, and photometric magnetic activity index,
    Sph from Kepler data, we have the opportunity to look for such magneto-gyro-chronology
    relations. Stellar ages are obtained with two stellar evolution codes that include
    treatment of angular momentum evolution, hence using Prot as input in addition
    to classical atmospheric parameters. We explore two different ways of predicting
    stellar ages on three subsamples with spectroscopic observations: solar analogs,
    late-F and G dwarfs, and K dwarfs. We first perform a Bayesian analysis to derive
    relations between Sph and ages between 1 and 5 Gyr, and other stellar properties.
    For late-F and G dwarfs, and K dwarfs, the multivariate regression favors the
    model with Prot and Sph with median differences of 0.1% and 0.2%, respectively.
    We also apply Machine Learning techniques with a Random Forest algorithm to predict
    ages up to 14 Gyr with the same set of input parameters. For late-F, G and K dwarfs
    together, predicted ages are on average within 5.3% of the model ages and improve
    to 3.1% when including Prot. These are very promising results for a quick age
    estimation for solar-like stars with photometric observations, especially with
    current and future space missions.'
acknowledgement: 'This paper includes data collected by the Kepler mission and obtained
  from the MAST data archive at the Space Telescope Science Institute (STScI). Funding
  for the Kepler mission is provided by the NASA Science Mission Directorate. STScI
  is operated by the Association of Universities for Research in Astronomy, Inc.,
  under NASA contract NAS 5–26555. We acknowledge that this research was supported
  in part by the National Science Foundation under grant No. NSF PHY-1748958. S.M.
  acknowledges support from the Spanish Ministry of Science and Innovation (MICINN)
  with the Ramón y Cajal fellowship No. RYC-2015-17697, the grant No. PID2019-107061GB-C66,
  and through AEI under the Severo Ochoa Centres of Excellence Programme 2020–2023
  (CEX2019-000920-S). S.M. and D.G.R. acknowledge support from the Spanish Ministry
  of Science and Innovation (MICINN) with the grant No. PID2019-107187GB-I00. Z.R.C.
  acknowledges support from National Aeronautics and Space Administration via the
  TESS Guest Investigator Program (grant No. 80NSSC18K18584). The work presented here
  was partially supported by the NASA grant NNX17AF27G. A.R.G.S. acknowledges the
  support by FCT through national funds and by FEDER through COMPETE2020 by the following
  grants: UIDB/04434/2020 and UIDP/04434/2020. A.R.G.S. is supported by FCT through
  the work contract No. 2020.02480.CEECIND/CP1631/CT0001. R.A.G., L.A., and S.N.B.
  acknowledge the support from PLATO and GOLF CNES grants. S.N.B. acknowledges support
  from PLATO ASI-INAF agreement No. 2015-019-R.1-2018.'
article_number: '131'
article_processing_charge: Yes
article_type: original
author:
- first_name: Savita
  full_name: Mathur, Savita
  last_name: Mathur
- first_name: Zachary R.
  full_name: Claytor, Zachary R.
  last_name: Claytor
- first_name: Ângela R. G.
  full_name: Santos, Ângela R. G.
  last_name: Santos
- first_name: Rafael A.
  full_name: García, Rafael A.
  last_name: García
- first_name: Louis
  full_name: Amard, Louis
  last_name: Amard
- first_name: Lisa Annabelle
  full_name: Bugnet, Lisa Annabelle
  id: d9edb345-f866-11ec-9b37-d119b5234501
  last_name: Bugnet
  orcid: 0000-0003-0142-4000
- first_name: Enrico
  full_name: Corsaro, Enrico
  last_name: Corsaro
- first_name: Alfio
  full_name: Bonanno, Alfio
  last_name: Bonanno
- first_name: Sylvain N.
  full_name: Breton, Sylvain N.
  last_name: Breton
- first_name: Diego
  full_name: Godoy-Rivera, Diego
  last_name: Godoy-Rivera
- first_name: Marc H.
  full_name: Pinsonneault, Marc H.
  last_name: Pinsonneault
- first_name: Jennifer
  full_name: van Saders, Jennifer
  last_name: van Saders
citation:
  ama: Mathur S, Claytor ZR, Santos ÂRG, et al. Magnetic activity evolution of solar-like
    stars. I. Sph–age relation derived from Kepler observations. <i>The Astrophysical
    Journal</i>. 2023;952(2). doi:<a href="https://doi.org/10.3847/1538-4357/acd118">10.3847/1538-4357/acd118</a>
  apa: Mathur, S., Claytor, Z. R., Santos, Â. R. G., García, R. A., Amard, L., Bugnet,
    L. A., … van Saders, J. (2023). Magnetic activity evolution of solar-like stars.
    I. Sph–age relation derived from Kepler observations. <i>The Astrophysical Journal</i>.
    American Astronomical Society. <a href="https://doi.org/10.3847/1538-4357/acd118">https://doi.org/10.3847/1538-4357/acd118</a>
  chicago: Mathur, Savita, Zachary R. Claytor, Ângela R. G. Santos, Rafael A. García,
    Louis Amard, Lisa Annabelle Bugnet, Enrico Corsaro, et al. “Magnetic Activity
    Evolution of Solar-like Stars. I. Sph–Age Relation Derived from Kepler Observations.”
    <i>The Astrophysical Journal</i>. American Astronomical Society, 2023. <a href="https://doi.org/10.3847/1538-4357/acd118">https://doi.org/10.3847/1538-4357/acd118</a>.
  ieee: S. Mathur <i>et al.</i>, “Magnetic activity evolution of solar-like stars.
    I. Sph–age relation derived from Kepler observations,” <i>The Astrophysical Journal</i>,
    vol. 952, no. 2. American Astronomical Society, 2023.
  ista: Mathur S, Claytor ZR, Santos ÂRG, García RA, Amard L, Bugnet LA, Corsaro E,
    Bonanno A, Breton SN, Godoy-Rivera D, Pinsonneault MH, van Saders J. 2023. Magnetic
    activity evolution of solar-like stars. I. Sph–age relation derived from Kepler
    observations. The Astrophysical Journal. 952(2), 131.
  mla: Mathur, Savita, et al. “Magnetic Activity Evolution of Solar-like Stars. I.
    Sph–Age Relation Derived from Kepler Observations.” <i>The Astrophysical Journal</i>,
    vol. 952, no. 2, 131, American Astronomical Society, 2023, doi:<a href="https://doi.org/10.3847/1538-4357/acd118">10.3847/1538-4357/acd118</a>.
  short: S. Mathur, Z.R. Claytor, Â.R.G. Santos, R.A. García, L. Amard, L.A. Bugnet,
    E. Corsaro, A. Bonanno, S.N. Breton, D. Godoy-Rivera, M.H. Pinsonneault, J. van
    Saders, The Astrophysical Journal 952 (2023).
date_created: 2023-08-01T14:19:16Z
date_published: 2023-08-01T00:00:00Z
date_updated: 2023-12-13T12:00:15Z
day: '01'
ddc:
- '520'
department:
- _id: LiBu
doi: 10.3847/1538-4357/acd118
external_id:
  isi:
  - '001034185700001'
file:
- access_level: open_access
  checksum: f12452834d7ed6748dbf5ace18af4723
  content_type: application/pdf
  creator: dernst
  date_created: 2023-08-02T07:42:26Z
  date_updated: 2023-08-02T07:42:26Z
  file_id: '13448'
  file_name: 2023_AstrophysicalJour_Mathur.pdf
  file_size: 4192386
  relation: main_file
  success: 1
file_date_updated: 2023-08-02T07:42:26Z
has_accepted_license: '1'
intvolume: '       952'
isi: 1
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: American Astronomical Society
quality_controlled: '1'
status: public
title: Magnetic activity evolution of solar-like stars. I. Sph–age relation derived
  from Kepler observations
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 952
year: '2023'
...
---
_id: '13447'
abstract:
- lang: eng
  text: Asteroseismology has transformed stellar astrophysics. Red giant asteroseismology
    is a prime example, with oscillation periods and amplitudes that are readily detectable
    with time-domain space-based telescopes. These oscillations can be used to infer
    masses, ages and radii for large numbers of stars, providing unique constraints
    on stellar populations in our galaxy. The cadence, duration, and spatial resolution
    of the Roman galactic bulge time-domain survey (GBTDS) are well-suited for asteroseismology
    and will probe an important population not studied by prior missions. We identify
    photometric precision as a key requirement for realizing the potential of asteroseismology
    with Roman. A precision of 1 mmag per 15-min cadence or better for saturated stars
    will enable detections of the populous red clump star population in the Galactic
    bulge. If the survey efficiency is better than expected, we argue for repeat observations
    of the same fields to improve photometric precision, or covering additional fields
    to expand the stellar population reach if the photometric precision for saturated
    stars is better than 1 mmag. Asteroseismology is relatively insensitive to the
    timing of the observations during the mission, and the prime red clump targets
    can be observed in a single 70 day campaign in any given field. Complementary
    stellar characterization, particularly astrometry tied to the Gaia system, will
    also dramatically expand the diagnostic power of asteroseismology. We also highlight
    synergies to Roman GBTDS exoplanet science using transits and microlensing.
article_number: '2307.03237'
article_processing_charge: No
arxiv: 1
author:
- first_name: Daniel
  full_name: Huber, Daniel
  last_name: Huber
- first_name: Marc
  full_name: Pinsonneault, Marc
  last_name: Pinsonneault
- first_name: Paul
  full_name: Beck, Paul
  last_name: Beck
- first_name: Timothy R.
  full_name: Bedding, Timothy R.
  last_name: Bedding
- first_name: Joss Bland-Hawthorn
  full_name: Joss Bland-Hawthorn, Joss Bland-Hawthorn
  last_name: Joss Bland-Hawthorn
- first_name: Sylvain N.
  full_name: Breton, Sylvain N.
  last_name: Breton
- first_name: Lisa Annabelle
  full_name: Bugnet, Lisa Annabelle
  id: d9edb345-f866-11ec-9b37-d119b5234501
  last_name: Bugnet
  orcid: 0000-0003-0142-4000
- first_name: William J.
  full_name: Chaplin, William J.
  last_name: Chaplin
- first_name: Rafael A.
  full_name: Garcia, Rafael A.
  last_name: Garcia
- first_name: Samuel K.
  full_name: Grunblatt, Samuel K.
  last_name: Grunblatt
- first_name: Joyce A.
  full_name: Guzik, Joyce A.
  last_name: Guzik
- first_name: Saskia
  full_name: Hekker, Saskia
  last_name: Hekker
- first_name: Steven D.
  full_name: Kawaler, Steven D.
  last_name: Kawaler
- first_name: Stephane
  full_name: Mathis, Stephane
  last_name: Mathis
- first_name: Savita
  full_name: Mathur, Savita
  last_name: Mathur
- first_name: Travis
  full_name: Metcalfe, Travis
  last_name: Metcalfe
- first_name: Benoit
  full_name: Mosser, Benoit
  last_name: Mosser
- first_name: Melissa K.
  full_name: Ness, Melissa K.
  last_name: Ness
- first_name: Anthony L.
  full_name: Piro, Anthony L.
  last_name: Piro
- first_name: Aldo
  full_name: Serenelli, Aldo
  last_name: Serenelli
- first_name: Sanjib
  full_name: Sharma, Sanjib
  last_name: Sharma
- first_name: David R.
  full_name: Soderblom, David R.
  last_name: Soderblom
- first_name: Keivan G.
  full_name: Stassun, Keivan G.
  last_name: Stassun
- first_name: Dennis
  full_name: Stello, Dennis
  last_name: Stello
- first_name: Jamie
  full_name: Tayar, Jamie
  last_name: Tayar
- first_name: Gerard T. van
  full_name: Belle, Gerard T. van
  last_name: Belle
- first_name: Joel C.
  full_name: Zinn, Joel C.
  last_name: Zinn
citation:
  ama: Huber D, Pinsonneault M, Beck P, et al. Asteroseismology with the Roman galactic
    bulge time-domain survey. <i>arXiv</i>. doi:<a href="https://doi.org/10.48550/arXiv.2307.03237">10.48550/arXiv.2307.03237</a>
  apa: Huber, D., Pinsonneault, M., Beck, P., Bedding, T. R., Joss Bland-Hawthorn,
    J. B.-H., Breton, S. N., … Zinn, J. C. (n.d.). Asteroseismology with the Roman
    galactic bulge time-domain survey. <i>arXiv</i>. <a href="https://doi.org/10.48550/arXiv.2307.03237">https://doi.org/10.48550/arXiv.2307.03237</a>
  chicago: Huber, Daniel, Marc Pinsonneault, Paul Beck, Timothy R. Bedding, Joss Bland-Hawthorn
    Joss Bland-Hawthorn, Sylvain N. Breton, Lisa Annabelle Bugnet, et al. “Asteroseismology
    with the Roman Galactic Bulge Time-Domain Survey.” <i>ArXiv</i>, n.d. <a href="https://doi.org/10.48550/arXiv.2307.03237">https://doi.org/10.48550/arXiv.2307.03237</a>.
  ieee: D. Huber <i>et al.</i>, “Asteroseismology with the Roman galactic bulge time-domain
    survey,” <i>arXiv</i>. .
  ista: Huber D, Pinsonneault M, Beck P, Bedding TR, Joss Bland-Hawthorn JB-H, Breton
    SN, Bugnet LA, Chaplin WJ, Garcia RA, Grunblatt SK, Guzik JA, Hekker S, Kawaler
    SD, Mathis S, Mathur S, Metcalfe T, Mosser B, Ness MK, Piro AL, Serenelli A, Sharma
    S, Soderblom DR, Stassun KG, Stello D, Tayar J, Belle GT van, Zinn JC. Asteroseismology
    with the Roman galactic bulge time-domain survey. arXiv, 2307.03237.
  mla: Huber, Daniel, et al. “Asteroseismology with the Roman Galactic Bulge Time-Domain
    Survey.” <i>ArXiv</i>, 2307.03237, doi:<a href="https://doi.org/10.48550/arXiv.2307.03237">10.48550/arXiv.2307.03237</a>.
  short: D. Huber, M. Pinsonneault, P. Beck, T.R. Bedding, J.B.-H. Joss Bland-Hawthorn,
    S.N. Breton, L.A. Bugnet, W.J. Chaplin, R.A. Garcia, S.K. Grunblatt, J.A. Guzik,
    S. Hekker, S.D. Kawaler, S. Mathis, S. Mathur, T. Metcalfe, B. Mosser, M.K. Ness,
    A.L. Piro, A. Serenelli, S. Sharma, D.R. Soderblom, K.G. Stassun, D. Stello, J.
    Tayar, G.T. van Belle, J.C. Zinn, ArXiv (n.d.).
date_created: 2023-08-02T07:30:43Z
date_published: 2023-07-06T00:00:00Z
date_updated: 2023-08-02T07:36:00Z
day: '06'
department:
- _id: LiBu
doi: 10.48550/arXiv.2307.03237
external_id:
  arxiv:
  - '2307.03237'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2307.03237
month: '07'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
status: public
title: Asteroseismology with the Roman galactic bulge time-domain survey
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2023'
...
---
_id: '14256'
abstract:
- lang: eng
  text: "Context. Space asteroseismology is revolutionizing our knowledge of the internal
    structure and dynamics of stars. A breakthrough is ongoing with the recent discoveries
    of signatures of strong magnetic fields in the core of red giant stars. The key
    signature for such a detection is the asymmetry these fields induce in the frequency
    splittings of observed dipolar mixed gravito-acoustic modes.\r\nAims. We investigate
    the ability of the observed asymmetries of the frequency splittings of dipolar
    mixed modes to constrain the geometrical properties of deep magnetic fields.\r\nMethods.
    We used the powerful analytical Racah-Wigner algebra used in quantum mechanics
    to characterize the geometrical couplings of dipolar mixed oscillation modes with
    various realistically plausible topologies of fossil magnetic fields. We also
    computed the induced perturbation of their frequencies.\r\nResults. First, in
    the case of an oblique magnetic dipole, we provide the exact analytical expression
    of the asymmetry as a function of the angle between the rotation and magnetic
    axes. Its value provides a direct measure of this angle. Second, considering a
    combination of axisymmetric dipolar and quadrupolar fields, we show how the asymmetry
    is blind to the unraveling of the relative strength and sign of each component.
    Finally, in the case of a given multipole, we show that a negative asymmetry is
    a signature of non-axisymmetric topologies.\r\nConclusions. Asymmetries of dipolar
    mixed modes provide a key bit of information on the geometrical topology of deep
    fossil magnetic fields, but this is insufficient on its own. Asteroseismic constraints
    should therefore be combined with spectropolarimetric observations and numerical
    simulations, which aim to predict the more probable stable large-scale geometries."
acknowledgement: The authors are grateful to the referee for her/his detailed and
  constructive report, which has allowed us to improve our article. S. M. acknowledges
  support from the CNES GOLF-SOHO and PLATO grants at CEA/DAp and PNPS (CNRS/INSU).
  We thank R. A. Garcia for fruitful discussions and suggestions.
article_number: L9
article_processing_charge: Yes (in subscription journal)
article_type: letter_note
arxiv: 1
author:
- first_name: S.
  full_name: Mathis, S.
  last_name: Mathis
- first_name: Lisa Annabelle
  full_name: Bugnet, Lisa Annabelle
  id: d9edb345-f866-11ec-9b37-d119b5234501
  last_name: Bugnet
  orcid: 0000-0003-0142-4000
citation:
  ama: 'Mathis S, Bugnet LA. Asymmetries of frequency splittings of dipolar mixed
    modes: A window on the topology of deep magnetic fields. <i>Astronomy and Astrophysics</i>.
    2023;676. doi:<a href="https://doi.org/10.1051/0004-6361/202346832">10.1051/0004-6361/202346832</a>'
  apa: 'Mathis, S., &#38; Bugnet, L. A. (2023). Asymmetries of frequency splittings
    of dipolar mixed modes: A window on the topology of deep magnetic fields. <i>Astronomy
    and Astrophysics</i>. EDP Sciences. <a href="https://doi.org/10.1051/0004-6361/202346832">https://doi.org/10.1051/0004-6361/202346832</a>'
  chicago: 'Mathis, S., and Lisa Annabelle Bugnet. “Asymmetries of Frequency Splittings
    of Dipolar Mixed Modes: A Window on the Topology of Deep Magnetic Fields.” <i>Astronomy
    and Astrophysics</i>. EDP Sciences, 2023. <a href="https://doi.org/10.1051/0004-6361/202346832">https://doi.org/10.1051/0004-6361/202346832</a>.'
  ieee: 'S. Mathis and L. A. Bugnet, “Asymmetries of frequency splittings of dipolar
    mixed modes: A window on the topology of deep magnetic fields,” <i>Astronomy and
    Astrophysics</i>, vol. 676. EDP Sciences, 2023.'
  ista: 'Mathis S, Bugnet LA. 2023. Asymmetries of frequency splittings of dipolar
    mixed modes: A window on the topology of deep magnetic fields. Astronomy and Astrophysics.
    676, L9.'
  mla: 'Mathis, S., and Lisa Annabelle Bugnet. “Asymmetries of Frequency Splittings
    of Dipolar Mixed Modes: A Window on the Topology of Deep Magnetic Fields.” <i>Astronomy
    and Astrophysics</i>, vol. 676, L9, EDP Sciences, 2023, doi:<a href="https://doi.org/10.1051/0004-6361/202346832">10.1051/0004-6361/202346832</a>.'
  short: S. Mathis, L.A. Bugnet, Astronomy and Astrophysics 676 (2023).
date_created: 2023-09-03T22:01:15Z
date_published: 2023-08-01T00:00:00Z
date_updated: 2023-09-06T11:05:58Z
day: '01'
ddc:
- '520'
department:
- _id: LiBu
doi: 10.1051/0004-6361/202346832
external_id:
  arxiv:
  - '2306.11587'
  isi:
  - '001046037700007'
file:
- access_level: open_access
  checksum: 7b30d26fb2b7bcb5b5be1414950615f9
  content_type: application/pdf
  creator: dernst
  date_created: 2023-09-06T07:13:19Z
  date_updated: 2023-09-06T07:13:19Z
  file_id: '14271'
  file_name: 2023_AstronomyAstrophysics_Mathis.pdf
  file_size: 458120
  relation: main_file
  success: 1
file_date_updated: 2023-09-06T07:13:19Z
has_accepted_license: '1'
intvolume: '       676'
isi: 1
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
publication: Astronomy and Astrophysics
publication_identifier:
  eissn:
  - 1432-0746
  issn:
  - 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Asymmetries of frequency splittings of dipolar mixed modes: A window on the
  topology of deep magnetic fields'
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 676
year: '2023'
...