Asteroseismic age constraints on the open cluster NGC 2477 using oscillating stars identified with TESS FFI

Abstract

The ages of pulsating stars in clusters can be determined by isochrone fitting and it can be further improved by asteroseismic modelling. We analyse the intermediate-age open cluster NGC2477, known to suffer from differential extinction, to explore if asteroseismology and clusters characteristics can help understand the metallicity, extinction and result in better age determinations than isochrone-fitting alone. We combine a multitude of recent observations from Gaia, high-resolution spectroscopy, and extinction maps to analyse the cluster and then search for and detect variability in the member stars using TESS FFI data. To interpret all of these data, we used stellar structure, evolution and oscillation codes. We performed an isochrone fitting to the cluster using publically-available isochrones, which provides a cluster age of between 0.6 to 1.1 Ga. Then using TESS Full-frame images, we analysed the time dimension of the members of this cluster. We created optimised pixel light curves using the $\mathtt{tessipack}$ package which allows us to consider possible contamination by nearby stars. Using these light curves, we identified many interesting levels of variability of stars in this cluster, including binaries and oscillating stars. For the asteroseismic analysis, we selected a few uncontaminated A--F type oscillating stars and used the MESA and GYRE codes to interpret the frequency signals. By comparing the theoretical and the observed spectra, we identified frequency separations, $\Delta \nu$, for four stars. Then using the identified $\Delta \nu$ and imposing that the best matched theoretical models have the same age, metallicity and background extinction, we constrained the cluster's age to 1.0 $\pm$ 0.1 Ga. We conclude that using the TESS FFI data, we can identify oscillating stars in clusters, which allows us to better refine their ages.

arXiv comment26 pages, 30 figures; accepted for publication in A&A

References in corpus (68)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• Gaia Data Release 2. Summary of the contents and survey properties
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Modules for Experiments in Stellar Astrophysics (MESA)
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Gaia Data Release 3: Summary of the content and survey properties
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• The K2 Mission: Characterization and Early results
• Presupernova Evolution of Rotating Massive Stars I: Numerical Method and Evolution of the Internal Stellar Structure
• The evolution of rotating stars
• Gaia Data Release 2: Photometric content and validation
• A Gaia DR2 view of the Open Cluster population in the Milky Way
• The Ages of Stars
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• The Radial Velocity Experiment (RAVE): Fifth Data Release
• Kepler Asteroseismology Program: Introduction and First Results
• Gaia Data Release 2: first stellar parameters from Apsis
• Presupernova Evolution of Rotating Massive Stars II: -- Evolution of the Surface Properties
• The Updated BaSTI Stellar Evolution Models and Isochrones: I. Solar Scaled Calculations
• Asteroseismology of old open clusters with Kepler: direct estimate of the integrated RGB mass loss in NGC6791 and NGC6819
• Probing the interior physics of stars through asteroseismology
• Rotation and magnetism of Kepler pulsating solar-like stars. Towards asteroseismically calibrated age-rotation relations
• The birth of the Milky Way as uncovered by accurate stellar ages with Gaia
• eleanor: An open-source tool for extracting light curves from the TESS Full-Frame Images
• Gaia Data Release 2: Properties and validation of the radial velocities
• 3D maps of interstellar dust in the Local Arm: using $Gaia$, 2MASS and APOGEE-DR14
• The evolution of the Galactic metallicity gradient from high-resolution spectroscopy of open clusters
• UPMASK: unsupervised photometric membership assignment in stellar clusters
• Asteroseismology of solar-type stars
• Giant star seismology
• How Good a Clock is Rotation? The Stellar Rotation-Mass-Age Relationship for Old Field Stars
• Gaia Data Release 3. Summary of the variability processing and analysis
• The Revolution Revolution: magnetic morphology driven spin-down
• The asteroseismic potential of TESS: exoplanet-host stars
• Bayesian Ages for Early-Type Stars from Isochrones Including Rotation, and a Possible Old Age for the Hyades
• On the metallicity of open clusters II. Spectroscopy
• Detailed analysis of open clusters: a mass function break and evidence of a fundamental plane
• The $AKARI$ Far-Infrared All-Sky Survey Maps
• The age of the Sun and the relativistic corrections in the EOS
• The GALAH survey: effective temperature calibration from the InfraRed Flux Method in the Gaia system
• New insights on Ba over-abundance in open clusters. Evidence for the intermediate neutron-capture process at play?
• The empirical Gaia G-band extinction coefficient
• Cluster Difference Imaging Photometric Survey. I. Light Curves of Stars in Open Clusters from TESS Sectors 6 & 7
• Characterizing solar-type stars from full-length Kepler data sets using the Asteroseismic Modeling Portal
• Red clump stars and Gaia: Calibration of the standard candle using a hierarchical probabilistic model
• The Asteroseismic Target List (ATL) for solar-like oscillators observed in 2-minute cadence with the Transiting Exoplanet Survey Satellite (TESS)
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- I. Search for exoplanets and variable stars in the field of 47 Tuc
• The First Detections of the Extragalactic Background Light at 3000, 5500, and 8000A (III): Cosmological Implications
• Observational $\Delta \nu$-$\bar{\rho }$ relation for $\delta$ Sct stars using eclipsing binaries and space photometry
• Precision Light Curves from TESS Full-Frame Images: A Difference Imaging Approach
• Detection of a young stellar population in the background of open clusters in the Third Galactic Quadrant
• Fitting Isochrones to Open Cluster photometric data: A new global optimization tool
• How accurate are stellar ages based on stellar models ? I. The impact of stellar models uncertainties
• Effects of rotation on the evolution and asteroseismic properties of red giants
• Mode visibilities in rapidly rotating stars
• Interstellar extinction in the open clusters towards galactic longitude around 130 degrees
• An Independent Calibration of Stellar Ages: HST Observations of White Dwarfs at V=25
• The White Dwarf Age of NGC 2477
• MESA models with magnetic braking
• A search for variable subdwarf B stars in TESS Full Frame Images -- I. Variable objects in the southern ecliptic hemisphere
• The eclipsing binary systems with $\delta$ Scuti component. I. KIC 10661783
• Fitting isochrones to open cluster photometric data III. Estimating metallicities from UBV photometry
• The blue straggler population of the open clusters Trumpler 5, Trumpler 20, and NGC 2477
• Clues on the Galactic evolution of sulphur from star clusters

Cited by in corpus (4)

• Asteroseismology of the young open cluster NGC 2516 I: Photometric and spectroscopic observations
• Age-dating the young open cluster UBC 1 with g-mode asteroseismology, gyrochronology, and isochrone fitting
• Identifying 850 delta Scuti pulsators in a narrow Gaia colour range with TESS 10-minute full-frame images
• Variable Stars in M31 Stellar Clusters from the Panchromatic Hubble Andromeda Treasury