GCN Circular 9649
D. Gotz (CEA-Saclay), S. Mereghetti (IASF-Milano), A. von Kienlin (MPE Garching), M. Beck (ISDC Versoix) report: The Swift GRB 090709A (Morris at al., GCN 9625) is clearly detected also in the data of Anticoincidence System (ACS) of the spectrometer SPI on board INTEGRAL. SPI-ACS consists on 91 BGO detectors that are sensitive to photons above 100 keV, and their light curves are continuously stored in 50 ms bins. No directional or spectral information is available. The light curve of GRB 090709A can be found here http://ibas.iasf-milano.inaf.it/090709Alc.jpg The ~8 s periodicity reported by Markwardt et al. (GCN 9645) in the Siwft/BAT data and by Golenetskii et al. (GCN 9647) in Konus-Wind data is clearly detected also in the SPI-ACS data. A periodogram over the entire burst duration can be found here http://ibas.iasf-milano.inaf.it/090709A.jpg By fitting the peak of the periodogram using a gaussian function one obtains a best period of 8.11 s. A light curve folded to the best period can be fond here http://ibas.iasf-milano.inaf.it/090709A_folded.jpg This message can be cited.