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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32537 results found.

  1. GRB040924: KAIT observations
  2. GRB040924: Afterglow magnitude at t=17.5hr
  3. GRB 040924: WSRT Radio Observations
  4. GRB 040924: NIR finding chart
  5. GRB040924 : Optical candidate observations at Lulin observatory
  6. GRB040924 : Optical candidate observations at Lulin observatory
  7. GRB 040924: Subaru NIR observation
  8. GRB 040924: RTT150 optical observations
  9. GRB 040924, optical follow-up
  10. GRB040924: MASTER: OT decay
  11. IPN triangulation of GRB040924 (H3564)
  12. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  13. XRF 040912: Radio Observations
  14. XRF 040916: Radio Observations
  15. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  16. XRF040916: continuing decay of OT
  17. TAROT Observations of GRB 040916 (HETE #3558)
  18. GRB040912(=H3557): Candidate Optical Afterglow
  19. XRF040916, optical observations
  20. XRF040916: Optical Transient Candidate by Subaru
  21. XRF 040912, identification of CXO sources
  22. XRF040916, Ic observations
  23. XRF040916: optical follow-up observations
  24. XRF040912, BVRcIc field calibration
  25. XRF040916, BVRcIc field calibration
  26. GRB040916: Archival optical observations
  27. XRF 040916, optical follow-up
  28. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  29. GRB040916: Optical observations
  30. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  31. GRB040916 (= H3558): A Long XRF Localized by HETE
  32. GRB040912 (= H3557): Chandra Observations Scheduled
  33. GRB 040912, BVRI observations
  34. GRB040912 : Kiso Optical follow-up observation
  35. IBAS GRB Alerts 1978-1980
  36. Optical observations of field of GRB040912
  37. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  38. GRB040903 - A XRF?
  39. GRB040827: analysis of the XMM-Newton observation
  40. GRB040903, REM near-IR observation
  41. GRB 040903 - INTEGRAL data analysis
  42. Very bright burst detected from SGR 1806-20
  43. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  44. Possible GRB 040903 - further analysis
  45. GRB 040827 - Radio Observations
  46. XMM-Newton Images of GRB 040827
  47. GRB040825A: Optical observations
  48. GRB040825A: Optical observations
  49. GRB 040827: optical and NIR observations at the VLT
  50. GRB 040827: UKIRT - 2nd epoch K-band imaging
  51. GRB 040827: 2nd epoch of Magellan K-band imaging
  52. GRB 040827: K imaging - no evidence of variability
  53. GRB 040827: Detection of NIR afterglow
  54. GRB 040827: Possible detection of optical afterglow
  55. GRB 040827: RTT150 optical observations
  56. MASTER: GRB040827 possible OT
  57. GRB 040825B: Optical observations
  58. GRB040827 optical observations
  59. GRB 040827 - Refined position
  60. GRB040825B, BVRcIc field photometry
  61. GCN GRB OBSERBATION REPORT
  62. GRB040825B: optical observations
  63. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  64. GRB040825B: Correction to GCN 2657
  65. XRF040812: possible afterglow second Chandra observation
  66. GRB 040812: Second epoch CXO Observations
  67. XRF040812: GMRT observations
  68. XRF 040812: optical observation at VLT
  69. GRB 040812: Optical counterparts of CXO sources
  70. XRF040812: possible afterglow
  71. CXO observation of GRB 040812
  72. IPN/HETE localizations of GRB040810 (=H3489)
  73. GRB 040812: Keck and LCO optical observations
  74. GRB 040812: Keck and LCO observations
  75. GRB 040812: radio observations
  76. GRB040812, optical/IR observations
  77. XRF040701: Optical Observations at ESO
  78. IPN/HETE triangulation of GRB040802 (=H3485)
  79. GRB 040730, infrared observations
  80. GRB 040730: Optical observations
  81. Ongoing activity of SGR 1806-20
  82. GRB040624: optical monitoring at TNG
  83. XRF 040701 - optical observations of the decaying Chandra source
  84. XRF040701: Second-Epoch Chandra Observations
  85. XRF040701: VLA Observations
  86. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  87. XRF040701: First-Epoch Chandra Observations
  88. GRB040709 J,H-band observations
  89. GRB040624, optical observations
  90. XRF 040701, optical observations
  91. GRB 040624: optical observations
  92. Optical Observations of GRB040624
  93. GRB 040624: optical observations at TNG and VLT
  94. GRB 040624: R-band observations
  95. GRB 040624, optical observations
  96. GRB 030329: Rebrightening of hyperluminal ejecta.
  97. IPN Summary of SGR1806-20 Activity in 2004
  98. GRB040511: Retraction of redshift identification
  99. SGR 1806-20: no IR variability of the proposed counterparts
  100. MASTER:HETE Alert 3259 (SRG1806-20) optical observation

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