The low-mass X-ray binary source Cyg X–3 has been extensively observed from radio to ultra-high-energy (UHE) gamma-ray energies (i.e., energies >1015eV). In the radio, Cyg X–3 exhibits intense non-thermal outbursts (flares) and a double-sided relativistic jet morphology. Interestingly, at energies above 1 TeV (1012eV), the gamma-ray emission is highly variable and possibly correlated with the radio outbursts. This emission results primarily from the radiative decay of π°-mesons generated in inelastic collisions between relativistic nuclei (predominantly protons) and the surrounding matter. The observed flux of UHE gamma-rays from Cyg X–3 implies that Cyg X–3 is a localised accelerator of such particles.

We propose a model of Cyg X–3 wherein particles expelled by the source are accelerated by Shockwaves in the relativistically expanding jets. Intense flaring episodes then lead to time variations in the ambient particle flux which account for the observed features at UHE energies.

SN 1987A has been observed with a combined high energy γ-ray (50-500 MeV) and hard X-ray (15-150 keV) payload during a balloon flight on 5 April 1988 from Alice Springs, Australia. The γ-ray observations, along with our earlier ones on 19 April 1987 are the only such observations of the supernova to date. The γ-ray detector characteristics are described. The preliminary results of the recent flight and their implications in terms of the known supernova parameters are discussed.

A strong diffuse C IV (5801-12 A) emission has been discovered in Berkeley 87 cluster near to the WR (WO) star ST3 (Barlow and Hummer, 1982) using the Loiano 152 cm telescope equipped with a Boiler and Chivens 26767 spectrograph and a CCD RCA camera. The diffuse emission seems to interest all the core of the cluster Berkeley 87. In fact it is present around many cluster members sited near to the center.