{
  "format": "text/markdown",
  "circularId": 9655,
  "submitter": "Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>",
  "version": 3,
  "eventId": "GRB 090709A",
  "editedOn": 1731923338150,
  "body": "A. J. Castro-Tirado (IAA-CSIC Granada), A. de Ugarte Postigo (OAB-INAF),\nJ. Gorosabel, S. Guziy, M. Jelínek (IAA-CSIC), P. Kubánek (IAA-CSIC and\nGACE Valencia), D. Pérez-Ramírez (Univ. de Jaén), N. Mirabal (UCM Madrid),\nA. Llorente, J. M. Castro Cerón (ESAC Villafranca del Castillo), C.\nAlvarez (IAC/GTC La Palma) and J. Cepa (IAC Tenerife),\n\nreport:\n\n\"Following the detection of GRB 090709A by Swift (Morris et al. GCNC\n9625), we have conducted follow-up observations with the 10.4-m Gran\nTelescopio Canarias (GTC) at the Observatorio del Roque de los Muchachos\nof the Instituto de Astrofísica de Canarias, in the island of La Palma.\nImages in the i'-band filter (7 x 300-s) under 1\".0 seeing were gathered\nwith the OSIRIS instrument (Cepa et al. 2009, in prep.) on 11 July 2009,\n00:45 UT (i.e. 41 hr after the event).\n\nAt the position of the reported nIR/optical afterglow (Aoki et al. GCNC\n9634, Morgan et al. GCNC 9635, Cenko et al. GCNC 9646) we detect no single\nobject down to i' ~ 25.5 (preliminary 3-sigma limit), or i' ~ 25.2 when\ntaking into account the foreground Galactic extinction. We note two nearby\nfaint objects, which lie 3\".3 south-east and 4\" north of the afterglow.\n\nThe stacked GTC .jpg image is available at the following link:\nhttp://www.iaa.es/~gss/GRB090709A\n\nAlthough we cannot exclude that GRB 090709A occurred in a low redshift\ngalaxy (Butler et al. GCNC 9639, Guidorzi et al. GCNC 9648), our\nnon-detection of a host galaxy, together with the reported 8-s\nquasi-periodic oscillations (Markwardt et al. GCN 9645, Golenetskii et al.\n9647, Gotz et al. GCNC 9649, Ohno et al. GCNC 9653) and the fact that the\nevent is at galactic coordinates of about (l = 91, b = 20) cannot rule out\nthat the initial observed gamma-ray emission arose from a nearby magnetar\ncandidate in the Milky Way, much closer than GRB 070610 / SWIFT\nJ195509+261406 (Castro-Tirado et al. 2008, Nature 455, 506).\nMultiwavelength observations are encouraged.\n\nWe acknowledge the excellent support from the GRANTECAN staff.\"\n\n\nThis Circular can be quoted.",
  "createdOn": 1247314718000,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "subject": "GRB 090709A: deep optical observation with the 10.4m GTC",
  "bibcode": "2009GCN..9655....1C",
  "email": "ajct@iaa.es"
}