8 research outputs found
The historical 1900 and 1913 outbursts of the binary blazar candidate OJ287
We report on historical optical outbursts in the OJ287 system in 1900 and 1913, detected
on archival astronomical plates of the Harvard College Observatory. The 1900 outburst is
reported for the first time. The first recorded outburst of the periodically active quasar
OJ287 described before was observed in 1913. Up to now the information on this event was
based on three points from plate archives. We used the Harvard plate collection, and added
another seven observations to the light curve. The light curve is now well covered and
allows one to determine the beginning of the outburst quite accurately. The outburst was
longer and more energetic than the standard 1983 outburst. Should the system be strictly
periodic, the period determined from these two outbursts would be 11.665 yr. However, this
does not match the 1900 outburst or other prominent outbursts in the record. On the other
hand, the precessing binary black hole model of Lehto and Valtonen (1996) can explain
these and other known outbursts in OJ287. Finally, we discuss the upper limits for the
expected 1906 outburst and the 1910 outburst, which was observed
The rainfall erosivity factor in the Czech Republic and its uncertainty
<div>R_factor_CZ_1989-2003.csv</div><div><br></div><div>Data for map of rainfall erosivity factor of</div><div><br></div><div>-----------------</div><div>Hanel, M., Máca, P., Bašta, P., Vlnas, R., Pech, P. (2016) The rainfall erosivity factor in the Czech Republic and its uncertainty. Hydrology and Earth System Sciences, 20, 1-16, doi: 10.5194/hess-20-1-2016.</div><div>-----------------</div><div><br></div><div>The file contains average R factor for the period 1989-2003 for 96 stations over the Czech Republic using 15 models for estimation of rainfall kinetic energy. </div><div> </div