TITLE: GCN CIRCULAR NUMBER: 9500 SUBJECT: Konus-RF observation of SGR burst 090605A DATE: 09/06/09 15:46:05 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin on behalf of the Konus-RF team, report: The first short burst from the newly discovered SGR 0418+5729 (van der Horst et al., GCN 9499) triggered Konus-RF gamma-ray spectrometer on-board the CORONAS-PHOTON solar space observatory at 2009-06-05 T0(KRF)=74449.134 s UT (20:40:49.134). The burst light curve shows a single pulse with a duration of ~0.02 s. There is a hint of a weak soft emission with a duration of ~0.03 s after the pulse. As observed by Konus-RF the burst had a fluence of (8.3 +/- 1.3)x10^-8 erg/cm2, and a 2-ms peak flux measured from T0-0.238 s of (1.53 +/- 0.43)x10^-5 erg/cm2/s (both in the 10 - 200 keV energy range). Preliminary analysis of the time-integrated spectrum shows that it is well fitted (in the 10 - 200 keV range) by OTTB model: dN/dE ~ E^(-1)*exp(-E/E0) with E0 = 35(-7, +8) keV (chi2 = 1.1/5 dof). All the quoted errors are at the 90% confidence level. The Konus-RF light curve of this burst is available at http://www.ioffe.ru/LEA/SGRs/090605_T74449/