Related papers: Strange pulsation modes in luminous red giants
The clear detection with CoRoT and KEPLER of radial and non-radial solar-like oscillations in many red giants paves the way to seismic inferences on the structure of such stars. We present an overview of the properties of the adiabatic…
Recent photometric observations of first-overtone classical Cepheids and RR Lyrae stars have led to the discovery of additional frequencies showing a characteristic period ratio of 0.60-0.65 with the main pulsation mode. In a promising…
We discuss the properties of pulsations in the OGLE Small Amplitude Red Giants (OSARGs) in the Large Magellanic Cloud (LMC). We consider stars below the red-giant tip in this paper. They are multi-periodic and form three sequences in the…
Several classes of pulsating stars are now known to undergo slow changes in amplitude; these include pulsating red giants and supergiants, and yellow supergiants. We have used visual observations from the AAVSO International Database, and…
Context. The advent of space-borne missions such as CoRoT or Kepler providing photometric data has brought new possibilities for asteroseismology across the H-R diagram. Solar-like oscillations are now observed in many stars, including red…
High-precision space observations, such as made by the \kepler\ and \corot\ missions, allow us to detect mixed modes for $l = 1$ modes in their high signal-to-noise photometry data. By means of asteroseismology, the inner structure of red…
The space-borne missions CoRoT and Kepler have provided a large amount of precise photometric data. Among the stars observed, red giants show a rich oscillation pattern that allows their precise characterization. Long-duration observations…
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…
When a star evolves into a red giant, the enhanced coupling between core-based gravity modes and envelope-based pressure modes forms mixed modes, allowing its deep interior to be probed by asteroseismology. The ability to obtain information…
Random changes in pulsation period are well established in cool pulsating stars, in particular the red giant variables: Miras, semi-regulars of types A and B, and RV Tau variables. Such effects are also observed in a handful of Cepheids,…
We introduce a new method to measure frequency separations and mode lifetimes of stochastically excited and damped oscillations, so-called solar-like oscillations. Our method shows that velocity data of the red giant star ksi Hya (Frandsen…
We use one-dimensional hydrodynamic calculations combined with synthetic stellar population models of the Magellanic Clouds to study the onset of self-excited pulsation in luminous red giants. By comparing the results with OGLE observations…
Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in…
Using our non-local time-dependent theory of convection, the linear non-adiabatic oscillations of 10 evolutionary model series with masses of 1--3M$_\odot$ are calculated. The results show that there is a red giant instability strip in the…
The space-borne missions CoRoT and Kepler opened up a new opportunity for better understanding stellar evolution by probing stellar interiors with unrivalled high-precision photometric data. Kepler has observed stellar oscillation for four…
We have identified 22 new variable red giants in 47 Tuc and determined periods for another 8 previously known variables. All red giants redder than V-I_c=1.8 are variable at the limits of our detection threshold, which corresponds to delta…
We present a phenomenological analysis of long-period variables (LPVs) in the Large Magellanic Cloud with the aim of detecting pulsation modes associated to different period-luminosity (PL) relations. Among brighter LPVs we discover a group…
Since the detection of non-radial solar-like oscillation modes in red giants with the CoRoT satellite, the interest in the asteroseismic properties of red giants and the link with their global properties and internal structure is…
We aim to describe the oscillation power excess observed in Kepler red giants, and to investigate empirical scaling relations governing these parameters. From these scalings relations, we derive new physical properties of red giant…
In cool stars that oscillate like the Sun, non-radial modes become mixed as the stars evolve. The mixing is caused by the coupling between g-modes in the stellar core and p-modes in the envelope, which results in distinctly different and…