243 research outputs found
Asteroseismic inversions in the Kepler era: application to the Kepler Legacy sample
In the past few years, the CoRoT and Kepler missions have carried out what is
now called the space photometry revolution. This revolution is still ongoing
thanks to K2 and will be continued by the Tess and Plato2.0 missions. However,
the photometry revolution must also be followed by progress in stellar
modelling, in order to lead to more precise and accurate determinations of
fundamental stellar parameters such as masses, radii and ages. In this context,
the long-lasting problems related to mixing processes in stellar interior is
the main obstacle to further improvements of stellar modelling. In this
contribution, we will apply structural asteroseismic inversion techniques to
targets from the Kepler Legacy sample and analyse how these can help us
constrain the fundamental parameters and mixing processes in these stars. Our
approach is based on previous studies using the SOLA inversion technique to
determine integrated quantities such as the mean density, the acoustic radius,
and core conditions indicators, and has already been successfully applied to
the 16Cyg binary system. We will show how this technique can be applied to the
Kepler Legacy sample and how new indicators can help us to further constrain
the chemical composition profiles of stars as well as provide stringent
constraints on stellar ages.Comment: To appear in the proceedings of the Kasc 9 Tasc 2 worksho
Non-adiabatic pulsations in ESTER models
One of the greatest challenges in interpreting the pulsations of rapidly
rotating stars is mode identification, i.e. correctly matching theoretical
modes to observed pulsation frequencies. Indeed, the latest observations as
well as current theoretical results show the complexity of pulsation spectra in
such stars, and the lack of easily recognisable patterns. In the present
contribution, the latest results on non-adiabatic effects in such pulsations
are described, and we show how these come into play when identifying modes.
These calculations fully take into account the effects of rapid rotation,
including centrifugal distortion, and are based on models from the ESTER
project, currently the only rapidly rotating models in which the energy
conservation equation is satisfied, a prerequisite for calculating
non-adiabatic effects. Non-adiabatic effects determine which modes are excited
and play a key role in the near-surface pulsation-induced temperature
variations which intervene in multi-colour amplitude ratios and phase
differences, as well as line profile variations.Comment: Proceedings for the Joint TASC2 & KASC9 Workshop, Terceira, Azores,
201
Mode identification in rapidly rotating stars from BRITE data
Apart from recent progress in Gamma Dor stars, identifying modes in rapidly
rotating stars is a formidable challenge due to the lack of simple, easily
identifiable frequency patterns. As a result, it is necessary to look to
observational methods for identifying modes. Two popular techniques are
spectroscopic mode identification based on line profile variations (LPVs) and
photometric mode identification based on amplitude ratios and phase differences
between multiple photometric bands. In this respect, the BRITE constellation is
particularly interesting as it provides space-based multi-colour photometry.
The present contribution describes the latest developments in obtaining
theoretical predictions for amplitude ratios and phase differences for
pulsation modes in rapidly rotating stars. These developments are based on full
2D non-adiabatic pulsation calculations, using models from the ESTER code, the
only code to treat in a self-consistent way the thermal equilibrium of rapidly
rotating stars. These predictions are then specifically applied to the BRITE
photometric bands to explore the prospects of identifying modes based on BRITE
observations.Comment: 8 pages, 3 figures, proceedings of the 3rd BRITE Science Worksho
2006-2007 Membership Meeting and Concert
Meet the Brass features the students of the brass department under the direction of Marc Reese, joined by the percussion student, Christopher Tusa.https://spiral.lynn.edu/foc-events/1003/thumbnail.jp
2018-2019 Alumni Recital - Peter Pirotte (Trumpet) and Carina Inoue (Piano)
2nd Annual Alumni Recita
2005-2006 Brass Ensemble
https://spiral.lynn.edu/conservatory_otherseasonalconcerts/1036/thumbnail.jp
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