Related papers: Automatic Method for Identifying Photospheric Brig…
We have produced a data base of V-band and B-band night-sky brightness measurements rather evenly spread out over the course of a whole sunspot cycle from September 1985 to August 1996. Almost all the data were obtained at the 2800-m level…
Solar granulation consists of dynamic convective plasma cells that rise from the solar interior to the surface. The interaction between these plasma cells and the Sun's magnetic field provides valuable insights into plasma dynamics near the…
High resolution imaging observation of a sunspot umbra was done with Hinode Solar Optical Telescope (SOT). Filtergrams in wavelengths of blue and green continuum were taken during three consecutive days. The umbra consisted of a dark core…
Although starburst galaxies have relatively flat spectral energy distributions, their strong optical emission lines and near-UV continua make it very feasible to estimate their redshifts photometrically. In this work, I describe a…
We present a new algorithm for the detection of flares in gamma-ray burst (GRB) light curves and use this algorithm to detect flares in the UV/optical. The algorithm makes use of the Bayesian Information Criterion (BIC) to analyze the…
Hydrodynamic simulations of granular convection predict the existence of supersonic flows covering ~3-4% of the solar surface at any time, but these flows have not been detected unambigously as yet. Using data from the spectropolarimeter…
Hubble Space Telescope allows us to study the central surface brightness profiles for globular clusters at unprecedented detail. We have mined the HST archives to obtain 38 WFPC2 images of galactic globular clusters with adequate exposure…
Determination of horizontal velocity fields on the solar surface is crucial for understanding the dynamics of structures like mesogranulation or supergranulation or simply the distribution of magnetic fields. We pursue here the development…
We present a new self-consistent and versatile method that derives photospheric radius and temperature variations of Type II-Plateau supernovae based on their expansion velocities and photometric measurements. We apply the method to a…
It is usual, in gamma-ray burst (GRB) studies, to compare the average properties of bright and faint GRBs, with the assumption that brightness classes reflect distance classes. When brightness is intented to reflect the distance to the…
We analyzed the size, intensity, and magnetic field strength of sunspot umbrae to compare the present cycle 24 with the previous one. We used data of the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory and selected…
Swirls are ubiquitous in the solar atmosphere. They are believed to be related to the excitation of different modes of magnetohydrodynamic waves and pulses, as well as spicules. However, statistical studies of their collective behaviour are…
We present results derived from the analysis of spectropolarimetric measurements of active region AR12546, which represents one of the largest sunspots to have emerged onto the solar surface over the last $20$ years. The region was observed…
High-resolution imaging observations from the Hinode spacecraft in the CaII H line are employed to study the dynamics of the chromosphere above a sunspot. We find that umbral flashes and other brightenings produced by the oscillation are…
We present a 106-minute TiO (705.7nm) time series of high spatial and temporal resolution that contains thousands of umbral dots (UDs) in a mature sunspot in the active region NOAA 10667 at $\mu$=0.95. The data were acquired with the 1-m…
A procedure is introduced to recognise sunspots automatically in solar full-disk photosphere images obtained from Huairou Solar Observing Station, National Astronomical Observatories of China. The images are first pre-processed through…
While gravitational wave (GW) standard sirens from neutron star (NS) mergers have been proposed to offer good measurements of the Hubble constant, we show in this paper how a variation of the expanding photosphere method (EPM) or…
We present UV luminosity functions (LFs) at 1500 Angstrom derived from the HST Early Release Science WFC3/UVIS data acquired over ~50 arcmin^2 of the GOODS-South field. The LFs are determined over the entire redshift range z=0.75-2.5 using…
Solar radio spikes are short lived, narrow bandwidth features in low frequency solar radio observations. The timing of their occurrence and the number of spikes in a given observation is often unpredictable. The high temporal and frequency…
This work reports a peculiar and interesting train of microwave type III pair bursts in the impulsive rising phase of a solar flare on 2011 September 26. The observations include radio spectrometers at frequency of 0.80 - 2.00 GHz, hard…