The paper looks at the question of measuring the importance of shocks to cycles. We consider two types of cycles - oscillations and those summarized by the NBER that require a study of growth in activity to establish turning points in the level of activity. The latter demarcate expansions and contractions. We establish a connection between these two concepts of cycles that shows shocks may have very different effects on each. As an application we look at a question that has often been asked over how important technology shocks are to cycles in activity? Some recent research concludes that total factor productivity (TFP) shocks are not important for oscillations and therefore models should be designed to reflect that. Using the same data we show that TFP shocks are very important to both types of cycles.

An extended catalog of long-periodic terms of the Sun tide-generating potential (STGP ver.2) is released. It contains 2.5 times of such terms than in the first version of the STGP catalog (Cionco et al. 2023). The analysis of the new data is done in order to re-examine the existence of tidal forces of ≈ 11.0-yr and ≈ 22.0-yr period able to excite the observed solar-activity cycles. In several recent studies, such tidal forcings are claimed to be a result of certain combinations of Venus, Earth and Jupiter mean motions with the multipliers (6, −10, 4) and (3, −5, 2), respectively. So, in this contribution, we specifically look for the periodic terms related to these combinations. As a result of these additional investigation we do not confirm any noticeable tidal forcing factors of ≈ 11.0-yr nor ≈ 22.0-yr period in the extended STGP spectrum either.

Ultra-massive (⩾M⊙) oxygen/neon (ONe) core white dwarfs (WDs) are the result of the evolution of isolated progenitor stars with masses above 6−M⊙. It is expected that hydrogen-rich (DA) ultra-massive WDs harbor crystallized cores at the typical temperatures of the ZZ Ceti instability strip. These stars offer a unique opportunity to study the processes of crystallization and to infer their core chemical composition. We present a study of the evolution and asteroseismology of ultra-massive DA WDs. We found that all pulsating WDs known to date with M⩾1.1M⊙ should have more than 80% of their mass crystallized, if a ONe-core is assumed. Finally, we present a complete asteroseismological analysis to the well known ZZ Ceti BPM 37093 and a preliminary analysis to GD 518 and SDSS J0840+5222.

Asteroseismology of white dwarf stars has led to a number of interesting results pertaining to the long term evolution and present state of white dwarf interiors. I will review recent results and will give a not necessarily comprehensive view of the prospects for further progress in this area. Two – but only two white dwarf stars - have shown the expected cooling as they age. Careful observations of a few white dwarfs with rich pulsational properties reveal interior compositions as well as the thickness of their surface layers. A few very well observed stars have revealed changes in their pulsational spectra which we don’t understand yet.

Convection is a highly turbulent, three dimensional process that is traditionally treated using a simple, local, time independent description. Convection is one of the largest sources of theoretical uncertainty in stellar modeling. We outline recent progress in studies using pulsating white dwarfs to constrain convection and calibrate mixing length theory.

Despite the critical role of working memory (WM) in neuropsychiatric conditions, there remains a dearth of available WM-targeted interventions. Gamma and theta oscillations as measured with electroencephalography (EEG) or magnetoencephalography (MEG) reflect the neural underpinnings of WM. The WM processes that fluctuate in conjunction with WM demands are closely correlated with WM test performance, and their EEG signatures are abnormal in several clinical populations. Novel interventions such as transcranial magnetic stimulation (TMS) have been shown to modulate these oscillations and subsequently improve WM performance and clinical symptoms. Systematically identifying pathological WM-related gamma/theta oscillatory patterns with EEG/MEG and developing ways to target them with interventions such as TMS is an active area of clinical research. Results hold promise for enhancing the outcomes of our patients with WM deficits and for moving the field of clinical neuropsychology towards a mechanism-based approach.

Non-smooth approximations of steep sigmoidal switching networks, such as those used as qualitative models of gene regulation, lead to analytic and computational challenges that arise as a result of the discontinuities in the vector fields. In order to highlight the need for care in dealing with such systems, several particular phenomena are presented here through illustrative examples, including ‘Zeno breaking’, or computing beyond the finite time convergence of an infinite sequence of threshold transitions; the ‘Contact’ effect, in which in the discontinuous limit, trajectories can pass through a ‘saddle point’ without stopping, though these solutions are not unique and other solutions stop for arbitrary time intervals; and sensitive behaviour that arises from exotic dynamics within switching regions.

New observations of Kepler δ Scuti stars show that our understanding of pulsation in these stars is incomplete. A large fraction of A and B stars exhibit rotational modulation in light, suggesting that spots exist in stars with radiative envelopes. Flares are seen in some A stars, as may be expected if starspots are present. Differential rotation shear increases from M to F but decreases for A stars; it reaches a maximum among the γ Doradus variables. Current views of stars with radiative envelopes may need to be reviewed in the light of these observations.

Following the LAMOST Spectroscopic Survey and Xuyi's Photometric Survey of the Galactic anti-center (GAC), we plan to conduct a time-domain survey of GAC to study the variable sky using Nanshan 1m telescope. The survey will be conducted during winter (in Nov., Dec., and Jan.). The first goal of the survey is to cover 270 sq.deg. of sky area in three years. The survey intends to detect some strong transient events of stars and find some short time-scale variable stars of different types. In this paper, we introduce the survey and present the preliminary results already carried out.

Two cases of filament oscillations induced by large-scale coronal shock waves are presented. For the first case, a chain of transverse oscillating filaments are observed in a proper order after the passing of a shock wave, and it is found that the they were triggered by the surface component of the dome-shaped shock wave. For the second case, simultaneous transverse oscillation of a limb prominence and longitudinal oscillation in an on-disk filament are launched by a single shock wave. It is found that the interaction angle between the shock wave and the prominence axis is the key to launch transverse or longitudinal filament oscillations. In addition, filament magnetic fields are estimated, using the measured parameters.

We present a brief progress report in our quest for deriving seismic models of pulsating white dwarfs that can account simultaneously for all the observed periods at the precision of the observations. We point out that this is possible from a pratical point of view only if parametrized models are used to complement evolutionary models. We adopt a double optimization procedure that insures that the best possible model in parameter space is found objectively and automatically. Our ultimate goal is to be able to account for the exquisite period data gathered with Kepler and Kepler-2 on key pulsating white dwarfs of both the DA (ZZ Ceti) and DB (V777 Her) type.

Coronal quasi-periodic fast-propagating (QFP) magnetosonic waves are scare in previous studies due to the relative low temporal and spatial resolution of past telescopes. Recently, they are detected by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). Here, two cases of QFP waves are presented. The analysis results indicate that QFP waves are tightly associated with the associated flares. It is indicate that QFP waves and the associated flares are possibly driven by the same physic process such as quasi-periodic magnetic reconnection process in producing flares.

Triple supermassive black holes (SMBH) can form during the hierarchical mergers of massive galaxies with an existing binary. Perturbations by a third black hole may accelerate the merging process of an inner binary, for example through the Kozai mechanism. We analyze the evolution of simulated hierarchical triple SMBHs in galactic centers, and find resonances in the evolution of the semi-major axis, the eccentricity and the inclination, for both the inner and the outer orbits of the triple system, which are not only Kozai like. Through resonant oscillations, SMBH can trigger a significant increase of the inner SMBH binary eccentricity shortening the merger timescale expected from gravitational wave (GW) emission. As hierarchical triple SMBHs may be frequent in massive galaxies, the influence of orbital resonances is of great importance to our understanding of black hole coalescence and gravitational wave detection. Although Kozai mechanism is believed to play an important role in this process, detailed studies on the pattern of these resonances is necessary.

Be stars are B-type stars near the main sequence which undergo episodic mass loss events detected by emission lines, whose line shape and intensity vary with a timescale of the order of decades. Spectroscopic observations show a large rotation velocity such that one of the prevailing scenarios for the formation of the equatorial disk consists in an increasing equatorial rotation velocity to the break-up limit where gravity is challenged by the centrifugal force. We investigate here a new scenario recently suggested by Ishimatsu & Shibahashi (2013), in which the transport of angular momentum through the photosphere would be achieved by leaky waves, keeping the rotation velocity still below the break-up limit.