Non-radial oscillations in M-giant semi-regular variables: Stellar models and Kepler observations

Abstract

The success of asteroseismology relies heavily on our ability to identify the frequency patterns of stellar oscillation modes. For stars like the Sun this is relatively easy because the mode frequencies follow a regular pattern described by a well-founded asymptotic relation. When a solar like star evolves off the main sequence and onto the red giant branch its structure changes dramatically resulting in changes in the frequency pattern of the modes. We follow the evolution of the adiabatic frequency pattern from the main sequence to near the tip of the red giant branch for a series of models. We find a significant departure from the asymptotic relation for the non-radial modes near the red giant branch tip, resulting in a triplet frequency pattern. To support our investigation we analyze almost four years of Kepler data of the most luminous stars in the field (late K and early M type) and find that their frequency spectra indeed show a triplet pattern dominated by dipole modes even for the most luminous stars in our sample. Our identification explains previous results from ground-based observations reporting fine structure in the Petersen diagram and sub ridges in the period-luminosity diagram. Finally, we find `new ridges' of non-radial modes with frequencies below the fundamental mode in our model calculations, and we speculate they are related to f modes.

arXiv comment8 page, 5 figures, accepted by ApJL (ApJ, 788, L10)

References in corpus (33)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Asteroseismology of Solar-Type and Red-Giant Stars
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• ADIPLS -- the Aarhus adiabatic oscillation package
• Calculating asteroseismic diagrams for solar-like oscillations
• ASTEC -- the Aarhus STellar Evolution Code
• Solar-like oscillations in low-luminosity red giants: first results from Kepler
• Theoretical amplitudes and lifetimes of non-radial solar-like oscillations in red giants
• The universal red-giant oscillation pattern; an automated determination with CoRoT data
• Asteroseismology of the open clusters NGC 6791, NGC 6811, and NGC 6819 from nineteen months of Kepler photometry
• Variable Stars in the Magellanic Clouds: Results from OGLE and SIRIUS
• Oscillations of alpha UMa and other red giants
• Red variables in the OGLE-II database. I. Pulsations and period-luminosity relations below the tip of the Red Giant Branch of the LMC
• Period-luminosity relations in evolved red giants explained by solar-like oscillations
• Seismic diagnostics of red giants: first comparison with stellar models
• Variable stars in the Magellanic Clouds: II. The data and infrared properties
• Long Period Variables in the Magellanic Clouds: OGLE + 2MASS + DENIS
• Infrared Period-Luminosity Relations of Evolved Variable Stars in the Large Magellanic Cloud
• Long Period Variables in the LMC: Results from MACHO and 2MASS
• Hipparcos period-luminosity relations for Miras and semiregular variables
• Solar-like oscillations of semiregular variables
• Solar-like oscillations and activity in Procyon: A comparison of the 2007 MOST and ground-based radial velocity campaigns
• Period-luminosity relations of pulsating M giants in the solar neighbourhood and the Magellanic Clouds
• Variability of M giant stars based on Kepler photometry: general characteristics
• The light curve of the semiregular variable L2 Puppis: II. Evidence for solar-like excitation of the oscillations
• Pulsation Modes of Long-Period Variables in the Period-Luminosity Plane
• Semiregular variables with periods lying between the period-luminosity sequences C', C and D
• Long Period Variables in the Large Magellanic Cloud from the EROS-2 survey
• Acoustic oscillations in stars near the tip of the red giant branch
• On the pulsation modes of OGLE small amplitude red giant variables in the LMC
• Dipolar modes in luminous red giants
• Red giant seismology: observations

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