The pulsating PG 1159 planetary nebula central star RXJ 2117+3412 has been observed over three successive seasons of a multisite photometric campaign. The asteroseismological analysis of the data, based on the 37 identified l=1 modes among the 48 independent pulsation frequencies detected in the power spectrum, leads to the derivation of the

An observing campaign with 10 participating observatories has undertaken to monitor the optical brightness of the Q0957 gravitationally lensed quasar for 10 consecutive nights in 2000 January. The resulting A image brightness curve has significant brightness fluctuations and makes a photometric prediction for the B image light curve for a second

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Substantial differences in the amplitudes of the fundamental frequency and its harmonics are observed in the temporal spectra of HP Lib in some specific nights. We interpret this photometric variations as a sign of the presence in the accretion disk of an active density wave which may develop changes in the energy production of the two spiral arms

We present preliminary results from a multisite photometric campaign on the intermediate polar V709 Cas carried out between Sept. 22 and Oct. 2, 2000. The combined white light data show a strong flickering and the presence of variability at the first harmonic of the beat (317.9 s) and a weak signal at the 312.8 s spin periods. We also detect a 5

During a serendipitous observation of the BeppoSAX Wide Field Cameras, a very long type I X-ray burst was observed from the low mass X-ray binary Serpens X-1. The burst lasted for approximately 4 hours and had an exponential decay time of 69+/-2 min (2-28 keV). The bolometric peak-luminosity is (1.6+/-0.2)*E38 erg s-1 and the fluence (7.3+/-1.4)