Evidence for a Supernova in the Ic Band Light Curve of the Optical Transient of GRB 970508

Unique data on $BVRI$ brightness curves of the OT of GRB 970508 obtained with the 6-m telescope have been interpreted in the framework of the GRB-SN (supernovae) connection. The effect must be maximal in the I_c band as OT GRB 970228. The peak absolute (M_B) magnitude of the suggested SN must be around -19.5 for the OT of GRB 970508. If all or the main part of long GRBs are associated with SNe, the GRB host galaxies (for ground-based observations, at least) must be dimmer than the peak magnitude of the SN.Comment: 3 pages, 2 figures, oral presentation on 2nd Rome Workshop on Gamma-Ray Bursts in the Afterglow Er

The gamma-ray bursts and core-collapse supernovae - global star forming rate peaks at large redshifts

This is a brief review on the first Gamma-Ray Bursts (GRB) optical identifications - GRB host galaxies and Star Forming Rate (SFR) at relatively small redshifts (z), on the metallicities of GRB hosts, the similarities and differences between GRB hosts and galaxies at larger z, and on the SFR and GRB rate (GRBR) at high z. Evidences of a direct connection between long-duration GRBs and massive stars explosions (like Core-Collapse Super-Novae - CCSNe) are presented. Is there a fast decrease in SFR up to z ~10? Some unsolved problems related to GRBs are discussed: about the high-z GRB host galaxies, the high-z CCSN-GRB connection, and possible new crucial cosmological tests at high z.Comment: 9 pages, 4 figures, to be published by "World Scientific" in Proceedings of the XXIX International Workshop on High Energy Physics: New Results and Actual Problems in Particle & Astroparticle Physics and Cosmology (HEPFT2013), 26-28 June 2013, Protvino, Moscow region, Russi