Did GRB 970228 and GRB 970508 present similar optical properties ?
نویسندگان
چکیده
The analysis of the light curves of the optical counterparts of GRB 970228 and GRB 970508 points out remarkable similarities. The spectral distribution obtained from the color indices shows that both the transients became bluer during the increasing stage, and redder after the maximum. A main difference concerns the behaviour of the optical fading which is well fitted by a single power law in the case of GRB 970508 but not in the case of GRB 970228.
منابع مشابه
X iv : a st ro - p h / 97 10 31 3 v 1 2 8 O ct 1 99 7 Did GRB 970228 and GRB 970508 present similar optical properties ?
The analysis of the light curves of the optical counterparts of GRB 970228 and GRB 970508 points out remarkable similarities. The spectral distribution obtained from the color indices shows that both the transients became bluer during the increasing stage, and redder after the maximum. A main difference concerns the behaviour of the optical fading which is well fitted by a single power law in t...
متن کاملar X iv : a st ro - p h / 97 10 31 3 v 2 3 1 O ct 1 99 7 Did GRB 970228 and GRB 970508 present similar optical properties ?
The analysis of the light curves of the optical counterparts of GRB 970228 and GRB 970508 points out remarkable similarities. The spectral distribution obtained from the color indices shows that both the transients became bluer during the increasing stage, and redder after the maximum. A main difference concerns the behaviour of the optical fading which is well fitted by a single power law in t...
متن کاملThe Optical Afterglow of Grb 971214: R and J Photometry
We present an R-band and J-band photometry of an optical transient which is likely to be associated with the gamma-ray burst event GRB 971214. Our first measurement took place 13 hours after the gamma-ray event. The brightness decayed with a power-law exponent α = −1.20 ± 0.02, which is similar to those of GRB 970228 and GRB 970508 which had exponents of α = −1.10 ± 0.04 and α = −1.141 ± 0.014 ...
متن کاملWind Interaction Models for Gamma-ray Burst Afterglows: the Case for Two Types of Progenitors
Beginning with the γ-ray bursts GRB 970228 and GRB 970508, a standard model for the interpretation of GRB afterglows emerged involving synchrotron emission from a constant energy blast wave expanding into a constant density, “interstellar” medium. However, a massive star origin for GRBs implies a stellar wind environment, probably a Wolf-Rayet star, and we have previously suggested wind interac...
متن کاملar X iv : a st ro - p h / 01 02 49 2 v 1 2 8 Fe b 20 01 Evidence for a Supernova in the Ic Band Light Curve of the Optical Transient of GRB 970508
Unique data on BV RI 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 Ic band as OT GRB 970228 [5]. The peak absolute (MB) 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...
متن کامل