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We report on the results of optical follow-up observations of the counterpart of GRB 970508, starting 7 hours after the event. Multi-color U, B, V, R$_{c}$ and I$_{c}$ band observations were obtained during the first three consecutive nights. The counterpart was monitored regularly in R$_{c}$ until $sim$ 4 months after the burst. The light curve after the maximum follows a decline that can be fitted with a power law with exponent $alpha$ = --1.141 $pm$ 0.014. Deviations from a smooth power law decay are moderate (r.m.s. = 0.15 magnitude). We find no flattening of the light curve at late times. The optical afterglow fluence is a significant fraction, $sim$ 5%, of the GRB fluence. The optical energy distribution can be well represented by a power law, the slope of which changed at the time of the maximum (the spectrum became redder).
There are the results of gamma-ray bursts observations obtained using the MASTER robotic telescope in 2007 - 2009. We observed 20 error-boxes of gamma-ray bursts this period.The limits on their optical brightnesses have been derived. There are 5 prom
We report on Westerbork 840 MHz, 1.4 and 5 GHz radio observations of the improved IPN-WFC error box of the gamma-ray burst GRB 970111, between 26.4 hours and 120 days after the event onset. In the ~ 13 sq arcmin area defined by the IPN (BATSE and Uly
We report on Westerbork 1.4 GHz radio observations of the radio counterpart to $gamma$-ray burst GRB~970508, between 0.80 and 138 days after this event. The 1.4 GHz light curve shows a transition from optically thick to thin emission between 39 and 5
We report on the deep optical follow-up surveys of the first two gravitational-wave events, GW150914 and GW151226, accomplished by the GRAvitational Wave Inaf TeAm Collaboration (GRAWITA) using the VLT Survey Telescope (VST). We responded promptly to
We have calculated synchrotron spectra of relativistic blast waves, and find predicted characteristic frequencies that are more than an order of magnitude different from previous calculations. For the case of an adiabatically expanding blast wave, wh