10 research outputs found
Rapid pulsations in sub-THz solar bursts
A new solar burst emission spectral component has been found showing sub-THz
fluxes increasing with frequency, spectrally separated from the well known
microwave component. Rapid pulsations are found present in all events observed
at the two frequencies of the solar submillimeter-wave telescope (SST): 212 and
405 GHz. They were studied in greater detail for three solar bursts exhibiting
the new THz spectral component. The pulse amplitudes are of about 5-8% of the
mean flux throughout the bursts durations, being comparable for both
frequencies. Pulsations range from one pulse every few seconds to 8-10 per
second. The pulse repetition rates (R) are linearly proportional to the mean
burst fluxes (S), following the simple relationship S = k R, suggesting that
the pulsations might be the response to discrete flare particle accelerator
injections quantized in energy. Although this result is consistent with
qualitative trends previously found in the GHz range, the pulse amplitude
relative to the mean fluxes at the sub-THz frequencies appear to be nearly ten
times smaller than expected from the extrapolation of the trends found in the
GHz range. However there are difficulties to reconcile the nearly simultaneous
GHz and THz burst emission spectrally separated components, exhibiting rapid
pulsations with considerably larger relative intensities in the GHz range.Comment: 9 pages and 11 figures, submitted to Astrophys. J; Revised version
accepted by ApJ on 4 March 200
The influence of starspots activity on the determination of planetary transit parameters
Physical conditions of the acceleration region of a solar flare with an unusually narrow gyrosynchrotron spectrum
V olimpĂada brasileira de astronomia
Neste trabalho, apresentamos os resultados da V OlimpĂada Brasileira de Astronomia, que ocorreu em 11/05/2002 em todos os estabelecimentos de ensino fundamental e mĂ©dio, previamente cadastrados. Participaram do evento 60.338 alunos, distribuĂdos por 1469 escolas pertencentes a todos os Estados brasileiros. Uma equipe de 5 alunos foi escolhida para representar o Brasil na VII OlimpĂada Internacional de Astronomia, que ocorreu na RĂşssia, em 2002, e dois de nossos alunos ganharam a medalha de bronze.In this work we show the results of the V Brazilian Olympiad of Astronomy, which took place on 11/05/2002 in all primary or secondary schools that previously registered. 60338 students distributed over 1.469 schools from all Brazilian States took part in this event. A team of 5 students was selected to represent Brazil at the VII International Olympiad of Astronomy that occurred in Russia in 2002. Two of our students were awarded the bronze medal in that event
V olimpĂada brasileira de astronomia
Neste trabalho, apresentamos os resultados da V OlimpĂada Brasileira de Astronomia, que ocorreu em 11/05/2002 em todos os estabelecimentos de ensino fundamental e mĂ©dio, previamente cadastrados. Participaram do evento 60.338 alunos, distribuĂdos por 1469 escolas pertencentes a todos os Estados brasileiros. Uma equipe de 5 alunos foi escolhida para representar o Brasil na VII OlimpĂada Internacional de Astronomia, que ocorreu na RĂşssia, em 2002, e dois de nossos alunos ganharam a medalha de bronze.In this work we show the results of the V Brazilian Olympiad of Astronomy, which took place on 11/05/2002 in all primary or secondary schools that previously registered. 60338 students distributed over 1.469 schools from all Brazilian States took part in this event. A team of 5 students was selected to represent Brazil at the VII International Olympiad of Astronomy that occurred in Russia in 2002. Two of our students were awarded the bronze medal in that event