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Category/Subcategory: Natural Sciences/Astronomy

Efficient solar scene wavefront estimation with reduced systematic and RMS centroid errors

Author: Narsireddy Anugu
Wave front sensing for solar telescopes is commonly implemented with Shack-Hartmann sensors. The Shack-Hartmann lenslet sub-aperture solar image shifts/slopes are usually estimated with correlation algorithms. The sub-pixel precis ... more

Views: 455

Measurements of helioseismic travel times

Author: Markus Roth
In time-distance helioseismology wave travel times are measured from the cross-correlation between Doppler velocities recorded at any two locations on the solar surface. All local helioseismology inferences rely critically on the ... more

Views: 396

Evolution of photospheric pores in the magnetic field

Author: Ivan Dorotovic
We describe conditions of pore formation in relation to the configuration and intensity of magnetic field. We used observations of the SDO/HMI instrument, which observes the photosphere in continuum and simultaneously the magnetic ... more

Views: 450

16CygA&B and Kepler Legacy values : Differences between the values of frequencies by different fitters

Author: Ian Roxburgh
The differences between the oscillation frequencies and uncertainty estimates of a star derived by different fitters can be large, sufficiently large so that, were one to find a stellar model that fitted one frequency set ($\chi^ ... more

Views: 795

KIC 6220497: a new Algol-type eclipsing binary with multiperiodic Pulsations

Author: Jae Woo Lee
We present both binarity and pulsation of KIC 6220497 from the {\it Kepler} observations. The light curve synthesis shows that the eclipsing system is a semi-detached Algol with parameters of $q$ = 0.243$\pm$0.001, $i$ = 77.3$\pm$ ... more

Views: 321

Measurements of the Absorption and Scattering Cross Sections for the Interactions of Solar Acoustic Waves with Sunspots

Author: Hui Zhao
The solar acoustic waves are modified by the interaction with sunspots. The interaction can be treated as a scattering problem: an incident wave propagating toward a sunspot is scattered by the sunspot into different modes. Th ... more

Views: 304

Seismic Inference of 58 Stars using full-length Kepler data sets

Author: Orlagh Creevey
We present stellar properties of 58 stars from a seismic inference using full-length data sets from Kepler (mass, age, radius, distances). These stars comprise active stars, planet-hosts, solar-analogs, and binary systems. By empl ... more

Views: 304

WP80: Synoptic Observations: Solar Physics Research Network Group (SPRING)

Author: Markus Roth
High-resolution telescopes (such as SST, GREGOR and the future EST and ATST) allow observations of only a small fraction of the solar surface. Real-time context data showing the large-scale dynamics and magnetism at different l ... more

Views: 248

High cadence observations and analysis of spicular-type events using CRISP onboard SST

Author: Juie Shetye
A statistical study of spectral images, taken from the CRISP instrument at the Swedish 1-m Solar Telescope in H-alpha 656.28 nm of fast spicules, present Doppler velocities in the range of -41km/s to +41 km/s. Remarkably, many ... more

Views: 368

Empirical Mode Decomposition studies of quasi-biennial variations in helioseismic frequencies

Author: Anne-Marie Broomhall
It is well-known that the Sun’s magnetic activity varies primarily on a time scale of 11yrs. It is also well known that the frequencies of the Sun’s natural acoustic oscillations vary in-phase with surface and atmospheric me ... more

Views: 460