{
  "bibcode": "1999GCN...416....1C",
  "body": "GRB 990915, optical observations\n---------------------------------\n\nAlberto Castro-Tirado, LAEFF-INTA (Madrid) and IAA-CSIC (Granada) \non behalf of a large collaboration:\nVictor Costa and Jose L. Ortiz, IAA-CSIC\nOliver Cordes, Martin Altmann and Daniel Harbeck, Univ. of Bonn\nJavier Gorosabel, LAEFF-INTA \nMara Salvato and Jochen Greiner, AIP (Potsdam)\nKevin Hurley, UCBerkeley/SSL \n\nreports:\n\n\"Following the detection of the strong burst GRB 990915 \nby BATSE and COMPTEL (Batse trigger # 7766) we have obtained:\n\n-150 frames (60-s, no filter, 20' x 13' FOV) at the 0.8-m \n Schmidt telescope of the German-Spanish Calar Alto Observatory \n (CAHA) starting 0.5 hr after the burst. The frames covered a \n significant fraction of the Hunstville/Locburst and COMPTEL \n error boxes and about a 15 % of the NEAR error box given by \n Hurley et al. in GCN 412. \n\n-25 frames (60-s, R-band, 16' x 16' FOV) at the 1.23-m CAHA \n telescope starting 30 hr after the burst. The frames covered an \n additional fraction (65 %) of the NEAR error box.\n\n-10 frames (150-s, R-band) at the 1.23-m CAHA telescope starting\n 50 hr after the burst. The frames covered the rest (20 %) of\n the NEAR error box.  \n\nAfter a careful visual comparison with the Digital Sky Survey, \nI have not found any source varying more than 0.3 mag when comparing \nto the DSS-1 charts, i.e. a limit of R > 20.5 can be imposed to the\nGRB 990915 optical afterglow.\"",
  "circularId": 416,
  "createdOn": 938337199000,
  "email": "ajct@laeff.esa.es",
  "subject": "GRB 990915 optical observations",
  "submitter": "Alberto Castro-Tirado at LAEFF-INTA  <ajct@laeff.esa.es>",
  "eventId": "GRB 990915"
}