25 Works

Helioseismology Overview and Solar Orbiter

Markus Roth
This presentation was given at the Solar Orbiter Science Activity Plan Meeting #4. It is a review on the techniques and achievements of helioseismology during the last decades. Furthermore, it gives an outlook on the science to be facilitated with ESA's space misison Solar Orbiter.

Asteroseismic modelling of the Binary HD 176465

Benard Nsamba
The detection and analysis of oscillations in binary star systems is critical in understanding stellar structure and evolution. This is because such systems have the same initial chemical composition and age. Solar-like oscillations have been detected in both components of the asteroseismic binary HD 176465 by Kepler (White et al., 2016). This study presents an independent modelling of the two stars in this binary system. Stellar models generated using MESA (Modules for Experiment in Stellar...

Spicules and their on-disk counterparts - The main driver for solar chromospheric heating? - The GREGOR Fabry-Perot Interferometer @ VTT

Klaus Gerhard Puschmann
Time series VI (14 min). Left panel - reconstructed white-light intensity-maps @ 656nm. Right panel - Hα Line Wing intensities. Remarkable feature - interaction of small-scale quiet-sun magnetic field at solar disk center, driven by the surrounding convection. Spicules are observed in consequence.

Solar Segmentation and Analysis of EUV Bright Points

Isabella Kraus
In my presentation I will talk about my upcoming master thesis about EUV bright points in the solar corona with AIA (Atmospheric Imaging Assembly) data from SDO (Solar Dynamics Observatory). Therefore I did some research of statistical properties of solar coronal bright points to compare them with the first results of our average bright point statistic (e.g.: number of bright points and their lifetime). Additionally, I will also show individual coronal bright points with their...

Straylight in data from the GREGOR Infrared Spectrograph

Morten Franz
In this contribution, we investigate to which degree strayligh influences results from the GREGOR Infrared Spectrograph. To this end, we use the synthesis module of the SIR code to perform radiative transfer calculations in a 3D-MHD model atmosphere of a full sunspot. We convolve the resulting Stokes spectra spatially and spectrally with theoretical point spread functions (PSF) as well as a PSF obtained during the Mercury transit and compare the results to GRIS observations.

Asteroseismic modelling of the Binary HD 176465

Benard Nsamba
The detection and analysis of oscillations in binary star systems is critical in understanding stellar structure and evolution. This is because such systems have the same initial chemical composition and age. Solar-like oscillations have been detected in both components of the asteroseismic binary HD 176465 by Kepler (White et al., 2016). This study presents an independent modelling of the two stars in this binary system. Stellar models generated using MESA (Modules for Experiment in Stellar...

From the Göttingen Fabry-Perot Interferometer to the Gregor FPI (presentation in 2006)

Klaus Gerhard Puschmann
Presentation in the frame of the Workshop Modern Solar Facilities - Advanced Solar Sience held in Göttingen from 27 - 29 September 2006. Fabry-Perot Interferometers (FPIs) have advantages over slit spectrographs, allowing fast two-dimensional, narrowband imaging and post factum image reconstruction of the spectropolarimetric data obtained. The resulting intensity, velocity and magnetic field maps are a fundamental base for the understanding of the dynamics of the solar atmosphere and its magnetic fields at smallest spatial...

Simulations of the Visible Tunable Filter for the Daniel K. Inouye Solar Telescope

Wolfgang Schmidt
The Visible Tunable Filter (VTF) is a narrowband tunable filter system for imaging spectroscopy and spectropolarimetry based. The instrument will be one of the first-light instruments of the Daniel K. Inouye Solar Telescope that is currently under construction on Maui (Hawaii). The VTF is being developed by the Kiepenheuer Institut fuer Sonnenphysik in Freiburg as a German contribution to the DKIST. We perform end-to-end simulations of spectropolarimetric observations with the VTF to verify the science...

Spicules and their on-disk counterparts - The main driver for solar chromospheric heating? - The GREGOR Fabry-Perot Interferometer @ VTT

Klaus Gerhard Puschmann
The standard picture of solar spicules: elongated highly dynamic jet-like features best seen in emission beyond the solar limb. Temporal evolution of Hα Line parameters for solar off-limb spicules; from left to right and top to bottom: Full width at half maximum (standard estimate, Gaussian Fit), line wing intensity, line core intensity, height distribution.

16CygAandB and Kepler Legacy values : Differences between the values of frequencies by different fitters

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 ($\chi^2\sim 1$), it does not fit an alternative set. I give 21 examples, comparing frequency sets in common between the Kepler Legacy project and frequency sets from Appourchaux et al (2014) and Davies et al (2015). For 16CygA\andB the differences...

The Si I 1082.7 nm line is in emission in sunspot umbrae

David Orozco Suarez
Determining empirical atmospheric models for the solar chormosphere is difficult since it requires the observation and analysis of spectral lines that are affected by non-local termodynamic equilibrium (NLTE) effects. Here we present Sunspot’s umbra data taken with the 1.5 m GREGOR telescope are analyzed after the effects of the stray-light on the data are removed using a novel deconvolution technique. The full Stokes measurements of a sunspot near disk center in the near-infrared spectral range...

First Results of HELLRIDE

Markus Roth
The HELioseismic Large Regions Interferometric Device (HELLRIDE) installed at the Vacuum Tower Telescope (VTT) in Izana, Tenerife has entered scientific mode in 2015. The instrument is a tunable filter that allows scanning sequentially through up to 32 spectral lines within short times delivering two-dimensional filtergrams of the Sun. In this talk I will summarize the capabilities of the instrument and present first results obtained during the 2015 observing campaigns.

Bacterial Identification Using 16S rDNA Gene Sequencing and Antibiogram Analysis on Biofield Treated Pseudomonas fluorescens

Gopal Nayak
Biofield therapies have been reported to improve the quality of life as compared to other energy medicine. The aim of the study was to evaluate the impact of Mr. Trivedi’s biofield energy treatment on Pseudomonas fluorescens (P. fluorescens) for antimicrobial sensitivity, minimum inhibitory concentration (MIC), biochemical reactions, and biotype number. P. fluorescens cells were procured from MicroBioLogics Inc., USA in sealed packs bearing the American Type Culture Collection (ATCC 49838) number and divided in control...

The Solar Physics Research Integrated Network Group – SPRING

Markus Roth
The Solar Physics Research Integrated Network Group (SPRING) is a project to develop a geographically distributed network of instrumentation to obtain synoptic solar observations. Building on the demonstrated success of networks to provide nearly-continuous long-term data for helioseismology, SPRING will provide data for a wide range of solar research areas. Scientific objectives include internal solar dynamics and structure; wave transport in the solar atmosphere; the evolution of the magnetic field over the activity cycle; irradiance...

Stell parameters of main sequence turn-off star candidates observed with the LAMOST and Kepler

Yaqian Wu
Main sequence turn-off (MSTO) stars are advantaged indicators of Galactic evo- lution since their ages could be robustly estimated by atmospheric parameters. Hundreds of thousands of MSTO stars have been selected from the LAMOST Galactic survey to study the evolution of the Galaxy, and it will be benefited from accurate estimates of stellar param- eters. In this work, we select 150 MSTO candidates in the LAMOST MSTO stars sample and constrain their stellar parameters with...

Über die Entlockung der Geheimnisse unseres Sterns

Klaus Gerhard Puschmann
Public Talk - Volkssternwarte Darmstadt

Physical formulation of the eigenfrequency condition of mixed modes of stellar oscillations

Masao Takata
The frequency condition for the mixed modes of nonradial stellar oscillations is generally examined by a simple physical model based on a running-wave picture. The coupling coefficient between the gravity-wave oscillation in the core and the acoustic-wave oscillation in the envelope is expressed in terms of the reflection coefficient at the intermediate evanescent region. It is also argued that the eigenmode condition should appropriately be modified if the wave generated near the surface and transmitted...

ON POSSIBLE EXPLANATIONS OF PULSATIONS IN MAIA STARS

Jadwiga Daszynska-Daszkiewicz
The long-time photometric surveys in a few young open clusters allowed to identify the light variability in stars located between the well defined  Scuti variables and Slowly Pulsating B-type stars (Mowlavi et al, 2013, 2015). The period of these changes is in the range of about 0.1 - 0.7 [d] corresponding to the frequencies of about 1.4 - 10 [d-1]. Several objects of this type were suggested also from the analysis of the Kepler...

SpaceInn - Results and Impact

Markus Roth
The collaborative project "SpaceInn - Exploitation of Space Data for Innovative Helio- and Asteroseismolgy" is funded under the European Union’s Seventh Framework Programme from January 2013 – December 2016. The European Helio- and Asteroseismology Network (HELAS) has initiated this project with the mission to build on the existing European strength in the field of time-domain stellar physics. In the last three years SpaceInn activities aimed to secure optimal use of the existing and planned data,...

Results of the measurement of the continuum flux in solar flares

Pavel Kotrč
Increase in the Balmer continuum radiation during solar flares was predicted by various authors, but has never been firmly confirmed observationally using ground-based slit spectrographs. We developed a new post-focal instrument, the image selector, with which the Balmer continuum flux can be measured from the whole flare area, in analogy to successful detections of flaring dMe stars. The system was put into operation at the horizontal solar telescope HSFA2 of the Ondřejov Observatory. We measure...

An estimate of chromosphericheatingby acoustic waves - reloaded

Michal Sobotka
Several mechanisms may heat the solar chromosphere: acoustic waves, magnetoacoustic waves (slow, fast, and Alfven waves), and small-scale magnetic reconnections. Based on observations in the Ca II 854.2 nm line, the contribution of acoustic waves to the heating of quiet and plage regions in the chromosphere is discussed. The point is to compare the energy released by radiative losses with the energy deposited by acoustic waves. Radiative losses are computed using a grid of semi-empirical...

The GREGOR Fabry-Perot Interferometer (GFPI) - Technical Innovations and Results achieved in 2013

Klaus Gerhard Puschmann
This contribution provides a summary of not yet published technical innovations to the GREGOR Fabry-Perot Interferometer (GFPI) at the 1.5m GREGOR Solar Telescope (Europe's largest solar telescope) that I implemented in 2013 as the Instrument Scientist of the GFPI. It also represents an overview of first important and not yet published observational results that I achieved with the GFPI in 2013. The results and achievements can be considered as a milestone in the scientific verification...

Spicules and their on-disk counterparts - The main driver for solar chromospheric heating? - The GREGOR Fabry-Perot Interferometer @ VTT

Klaus Gerhard Puschmann
Time series VI (14 min). Left panel - reconstructed white-light intensity-maps @ 656nm. Right panel - Hα Line Wing intensities. Remarkable feature - interaction of small-scale quiet-sun magnetic field at solar disk center, driven by the surrounding convection. Spicules are observed in consequence.

Tornadoes in the solar atmosphere: Velocity streamlines

Christian Nutto
The sequence shows the evolution of dynamic structures resembling tornadoes in the solar atmosphere. The red lines represent stream lines of the velocity field in the solar atmosphere. The contour shows the dynamic evolution of the $\beta=1$ layer.

JCMT and the East Asia Observatory

Michael Burton
An overview of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii and the East Asia Observatory

Registration Year

  • 2016
    25

Resource Types

  • Audiovisual
    25

Data Centers

  • SMN ScienceMedia Network GmbH
    25