{
  "bibcode": "2009GCN..9649....1G",
  "body": "D. Gotz (CEA-Saclay), S. Mereghetti (IASF-Milano), A. von Kienlin (MPE  \nGarching), M. Beck (ISDC Versoix)  report:\n\nThe Swift GRB 090709A (Morris at al., GCN 9625) is clearly detected  \nalso in the data of Anticoincidence System (ACS) of the spectrometer  \nSPI on board INTEGRAL. SPI-ACS consists on 91 BGO detectors that are  \nsensitive to photons above 100 keV, and their light curves are  \ncontinuously stored in 50 ms bins. No directional or spectral  \ninformation is available. The light curve of GRB 090709A  can be found  \nhere\n\nhttp://ibas.iasf-milano.inaf.it/090709Alc.jpg\n\nThe ~8 s periodicity reported by Markwardt et al. (GCN 9645) in the  \nSiwft/BAT data and by Golenetskii et al. (GCN 9647) in Konus-Wind data  \nis clearly detected also in the SPI-ACS data. A periodogram over the  \nentire burst duration can be found here\n\nhttp://ibas.iasf-milano.inaf.it/090709A.jpg\n\nBy fitting the peak of the periodogram using a gaussian function one  \nobtains a best period of 8.11 s. A light curve folded to the best  \nperiod can be fond here\n\nhttp://ibas.iasf-milano.inaf.it/090709A_folded.jpg\n\n\nThis message can be cited.",
  "circularId": 9649,
  "createdOn": 1247228128000,
  "email": "diego.gotz@cea.fr",
  "subject": "GRB 090709A: confirmation of the periodicity in the SPI-ACS data",
  "submitter": "Diego Gotz at CEA  <diego.gotz@cea.fr>",
  "eventId": "GRB 090709A"
}