Related papers: Frequency Regularities in $\delta$ Scuti Stars
Inspection of the periodograms of TESS delta Scuti stars indicates that there is little, if any, similarity between the frequencies of stars in the same region of the H-R diagram. This is difficult to understand because pulsation models…
We present a seismic study of $\delta$ Scuti based on a mode identification from multicoulor photometry. The dominant frequency can be associated only with a radial mode and the second frequency is, most probably, a dipole mode. The other…
The main obstacle in exploiting the frequency data of $\delta$ Sct stars is difficulty in mode identification. The $\delta$ Sct oscillation spectra, unlike those of the Sun or white dwarfs, do not exhibit very regular patterns. Thus, the…
Only a fraction of the theoretically predicted nonradial pulsation modes have so far been observed in Delta Scuti stars. Nevertheless, the large number of frequencies detected in recent photometric studies of selected Delta Scuti stars…
In the last years, space missions such as COROT, Kepler or MOST have provided very accurate photometric observational data. In the particular case of $\delta$ Scuti stars, the observed frequency spectra have hundreds (if not thousands) of…
Pulsating stars are remarkable objects for stellar astrophysics. Their pulsation frequencies allow us to probe the internal structure of stars. One of the most known groups of pulsating stars is $\delta$ Scuti variables which could be used…
Thanks to high-precision photometric data legacy from space telescopes like CoRoT and Kepler, the scientific community could detect and characterize the power spectra of hundreds of thousands of stars. Using the scaling relations, it is…
The phenomenology associated with line profile variations in delta Scuti stars is reviewed. The three main techniques adopted to detect pulsation modes, i.e., the pixel-by-pixel analysis, the analysis of the moment time series and the…
Statistical analyses of several Delta Scuti stars (FG Vir, 44 Tau, BL Cam and others) show that the photometrically observed frequencies cluster around the frequencies of the radial modes over many radial orders. The observed regularities…
Many stars exhibit stellar pulsations, favoring them for asteroseismic analyses. Interpreting the oscillations requires some knowledge of the oscillation mode geometry (spherical degree, radial and azimuthal orders). The delta Scuti stars…
Space-based photometry reveals regular high-frequency patterns in many young $\delta$ Scuti stars. These pulsations provide a powerful means of inferring stellar properties, particularly ages, for young $\delta$ Scuti stars for which…
The long-time photometric surveys in a few young open clusters allowed to identify the light variability in stars located on the HR diagram between the well defined $\delta$ Scuti variables and Slowly Pulsating B-type stars. Several objects…
Fractal behaviour, i.e. scale invariance in spatio-temporal dynamics, have been found to describe and model many systems in nature, in particular fluid mechanics and geophysical related geometrical objects, like the convective boundary…
The aspects of the analysis of photometric time-series obtained on double-mode or multiperiodic pulsating stars are briefly reviewed. In particular, the ratios between frequencies are used to pin cases revealing peculiarities. In addition…
Amplitude and phase variability are commonly found in many different types of pulsating stars. This suggests a common, presently unknown physical origin. We have examined the phenomenon in several Delta Scuti stars with extensive data and…
$\delta$ Scuti stars are pulsating variable stars that exhibit both radial and non-radial pulsations, making them key objects for understanding stellar evolution and internal structures. The current classification of $\delta$ Scuti stars…
The high accuracy of space data increased the number of the periodicities determined for pulsating variable stars, but the mode identification is still a critical point in the non-asymptotic regime. We use regularities in frequency spacings…
Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise…
In addition to revealing spherical harmonic degrees, $\ell$, of excited modes, pulsational amplitudes and phases from multicolour photometry and radial velocity data yield a valuable constraints on stellar atmospheric parameters and on…
The multi-color CCD photometric study of 27 Delta Scuti stars is presented. By using approximately three years of photometric observations, we obtained the times of maxima and magnitude changes during the observation time interval for each…