Related papers: Solar Cycle Related Changes at the Base of the Con…
We analyze intermediate degree p- and f-mode eigenfrequencies measured by GONG and MDI/SOHO for a complete solar cycle to study their correlation with solar activity. We demonstrate that the frequencies do vary linearly with the activity,…
Solar activity is studied using a cluster analysis of the time-fluctuations of sunspot number. In the historic period (1850-1932) the cluster exponent was approximately equal to 0.37 (strong clustering) for the high activity components of…
We examine the frequency shifts in low-degree helioseismic modes from the Birmingham Solar-Oscillations Network (BiSON) covering the period from 1985 - 2016, and compare them with a number of global activity proxies well as a…
We present new results on the structure of the solar core, obtained with new sets of frequencies of solar low-degree p modes obtained from the BiSON network. We find that different methods used in extracting the different sets of…
Solar p-mode frequencies vary with solar activity. It is important to take this into account when comparing the frequencies observed from epochs that span different regions of the solar cycle. We present details of how to correct observed…
For the first time, a multi-wave research of oscillation dynamics in a solar facula from its birth to decay was carried out. We performed spectral observations of active region NOAA 12744 at Horizontal Solar Telescope of the Sayan Solar…
We carry out non-rotating high-resolution calculations of the solar global convection, which resolve convective scales of less than 10 Mm. To cope with the low Mach number conditions in the lower convection zone, we use the reduced speed of…
We have analysed temporal evolution in centroid frequencies and splitting coefficients of solar f-modes obtained from MDI/SOHO. The data were divided into 20 sets covering a period from May 1, 1996 to August 31, 2000. The variation in…
Although there are now some tentative signs that the start of cycle 24 has begun there is still considerable interest in the somewhat unusual behaviour of the current solar minimum and the apparent delay in the true start of the next cycle.…
Oscillations in solar-like oscillators tend to follow an approximately regular pattern in which oscillation modes of a certain degree and consecutive order appear at regular intervals in frequency, i.e. the so-called large frequency…
The oscillations of a spherical body consisting of hot electron-nuclear plasma are considered. It is shown that there are two basic modes of oscillations. The estimation of the main frequencies of the solar core oscillation gives a…
To better understand the influence of the activity cycle on the solar atmosphere, we report the time variation of the radius observed at 37 GHz ($\lambda$=8.1 mm) obtained by the Mets\"ahovi Radio Observatory (MRO) through Solar Cycles 22…
The solar magnetic activity consists of two periodic components: the main cycle with a period of 11 yr and a shorter cycle with a period of ~2 yrs. The origin of this second periodicity is still not well understood. We use almost 15 yrs of…
Context. There remains much mystery about how or if wave-energy in the photosphere can be transferred sufficiently upwards through the solar atmosphere to contribute to coronal heating. In light of a plethora of theoretical and idealised…
Oscillations of the Sun and solar-like stars are believed to be excited stochastically by convection near the stellar surface. Theoretical modeling predicts that the resulting amplitude increases rapidly with the luminosity of the star.…
Power-spectrum analyses of the decay rates of certain nuclides reveal (at very high confidence levels) an annual oscillation and periodicities that may be attributed to solar rotation and to solar r-mode oscillations. A comparison of…
AIM: To study the variation of the angular momentum and the rotational kinetic energy of the Sun, and associated variations in the gravitational multipole moments, on a timescale of the solar cycle. METHOD: Inverting helioseismic rotational…
Data obtained by the GONG and MDI instruments over the last seven years are used to study how solar dynamics -- both rotation and other large scale flows -- have changed with time. In addition to the well known phenomenon of bands of faster…
Solar-like oscillations are excited stochastically by convection. They occur in stars with an outer convection zone, which includes the Sun and other stars on the lower main sequence, as well as cool subgiants and red giants. This chapter…
In solar-like stars, acoustic modes provide the main way of probing their internal structure and dynamics. Although these modes are expected to be ubiquitous in stars with convective envelopes, Kepler observations reveal that a significant…