相关论文: A study of solar photospheric temperature gradient…
Context. The contribution of quiet-Sun regions to the solar irradiance variability is currently unclear. Some solar-cycle variations of the quiet-Sun physical structure, such as the temperature gradient, might affect the irradiance. The…
The Total Solar Irradiance varies over a solar cycle of 11 years and maybe over cycles with longer period. Is the solar diameter variable over time too? We introduce a new method to perform high resolution astrometry of the solar diameter…
Stars appear darker at their limbs than at their disk centers because at the limb we are viewing the higher and cooler layers of stellar photospheres. Limb darkening derived from state-of-the-art stellar atmosphere models systematically…
We compute the emergent stellar spectra from the UV to far infrared for different viewing angles using realistic 3D model atmospheres for a large range in stellar parameters to predict the stellar limb darkening. We have computed full 3D…
Small-scale magnetic fields can be observed on the Sun in high resolution G-band filtergrams as magnetic bright points (MBPs). We study Hinode/ Solar Optical Telescope (SOT) longitude and latitude scans of the quiet solar surface taken in…
We present grids of limb-darkening coefficients computed from non-LTE, line-blanketed TLUSTY model atmospheres, covering effective-temperature and surface-gravity ranges of 15--55kK and 4.75 dex (cgs) down to the effective Eddington limit,…
In order to perform high resolution astrometry of the solar diameter from the ground, through the observations of eclipses, the study of the limb darkening profile is described. Knowing the profile of the solar limb is useful both to…
A discussion of the solar diameter and its variations must be linked to the limb darkening function (LDF). We introduce a new method to perform high resolution astrometry of the solar diameter from the ground, through the observations of…
The Solar Diameter Monitor measured the duration of solar meridian transits during the 6 years 1981 to 1987, spanning the declining half of solar cycle 21. We have combined these photoelectric measurements with models of the solar…
We examine continuous measurements of the high-degree acoustic mode frequencies of the Sun covering the period from 2001 July to June 2014. These are obtained through the ring-diagram technique applied to the full-disk Doppler observations…
Solar irradiance variations over solar rotational time-scales are largely determined by the passage of magnetic structures across the visible solar disk. Variations on solar cycle time scales are thought to be similarly due to changes in…
We introduce a new method to perform high resolution astrometry of the solar diameter from the ground, through the observations of eclipses. A discussion of the solar diameter and its variations is linked to the Limb Darkening Function…
Measurements from the Solar Irradiance Monitor (SIM) onboard the SORCE mission indicate that solar spectral irradiance at Visible and IR wavelengths varies in counter phase with the solar activity cycle. The sign of these variations is not…
The solar limb darkening function is well known and is widely employed in models of the solar atmosphere. However, there has been a lack of systematic spectrally resolved measurements. Therefore we recently decided to start an observing…
For the first time, we present and discuss EUV radiances of the solar transition region (TR) and corona obtained during a solar cycle. The measurements were obtained with the SOHO/coronal diagnostic spectrometer (CDS) during the period from…
Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode…
We explore the sensitivity of limb darkening coefficients computed from stellar atmosphere models to different least-squares fitting methods. We demonstrate that conventional methods are strongly biased to fitting the stellar limb. Our…
We have examined images from the Precision Solar Photometric Telescope (PSPT) at the Mauna Loa Solar Observatory (MLSO) in search of latitudinal variation in the solar photospheric intensity. Along with the expected brightening of the solar…
The Galactic cosmic ray spectrum manifests pronounced variations over the 11-year sunspot cycle and more subtle variations over the 22-year solar magnetic cycle. An important tool to study these variations is repeated latitude surveys with…
Science Verification (SV) data of solar observations with Atacama Large Millimeter-submillimeter Array (ALMA) telescope were released to the scientific community. Understanding the centre to limb brightness function is necessary to compare…