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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"

35963 results found.

  1. GRB 050124: NIR Candidates from Keck/NIRC
  2. GRB050124,optical observation
  3. GRB 050124 : Lulin R-band follow-up observation
  4. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  5. GRB 050123 : I-band follow-up observation
  6. GRB050123: optical limit 1.8h before GRB
  7. GRB050123,optical observation
  8. GRB 050123: KAIT observations
  9. GRB050123: P60 Observations
  10. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  11. CFHTLS optical transient unlikely to be a GRB
  12. Unusual optical transient (GRB ???)
  13. GRB050117a: Radio Observations
  14. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  15. GRB 050117, I-band observations
  16. GRB 050117: Optical observation
  17. GRB050117: Refined XRT position
  18. GRB050117: MASTER optical observations
  19. MASTER:GRB050117 SWIFT
  20. GRB050117: Swift-BAT detection of a long multi-peaked burst
  21. Triangulation of Short Hard GRB050112 (large error box)
  22. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  23. SGR 1806-20 and extragalactic short-duration GRBs
  24. SGR 1806-20: Temporal and Spectral behavior of radio transient
  25. SGR 1806-20, RHESSI observations of the 041227 giant flare
  26. SGR1806: Detection of a Sudden Ionospheric Disturbance
  27. GRB 041217: Optical observations
  28. GRB041219, early time observations
  29. IPN localization of giant flare from SGR1806-20
  30. GRB041219; RXTE ASM Observations
  31. NIR Observations of GRB 041219
  32. GRB041223: decay of the afterglow
  33. GRB 041224: near-infrared observations with REM
  34. GRB 041223: XRT afterglow spectrum and light curve
  35. GRB 041223 Fluence measured by Swift-BAT
  36. GRB041223: optical and NIR observations with REM
  37. GRB 041219: TAROT optical observations
  38. GRB 041218: TAROT optical observations
  39. GRB 041223: J-band observations of the afterglow
  40. GRB 041223: Detection of Optical Transient with LCO40
  41. GRB 041219c: PROMPT Observations
  42. GRB 041218: optical observations
  43. GRB 041219: Second Epoch WSRT Radio Observations
  44. GRB 041219: WSRT Radio Afterglow Detection
  45. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  46. GRB 041218: Optical observations
  47. GRB 041219 : optical follow-up observations
  48. Deep RAPTOR observations during GRB 041219
  49. GRB 041218 Optical Observations
  50. GRB 041219 Optical Observations
  51. GRB041219c: Third Burst in One Day from Swift-BAT
  52. GRB041219: Optical Afterglow Detection
  53. GRB041219: Continued NIR Observations
  54. GRB 041219 ,optical observation
  55. GRB 041219: Radio Afterglow Detection
  56. GRB 041218 : Radio Observations
  57. GRB 041218: R-band optical observations
  58. GRB041219: Confirmed NIR Afterglow
  59. GRB041218: Continued P60 Optical Observations
  60. GRB 041218: Optical Observation
  61. GRB 041219: Infrared Afterglow Candidate
  62. GRB041219, BVRcIc field calibration
  63. GRB 041219: Infrared Afterglow Candidate
  64. GRB041218, BVRcIc field calibration
  65. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  66. GRB041219: P60 Optical Observations
  67. GRB 041219 - A long GRB detected by INTEGRAL
  68. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  69. GRB 041217: PROMPT Observations
  70. GRB041218: optical observations
  71. GRB041217: optical limit 30 min after GRB
  72. GRB 041218; optical candidate
  73. GRB 041218: Optical observations
  74. GRB 041217: LCO40 Optical Observations and Possible Candidates
  75. GRB 041218 - A long GRB detected by integral
  76. GRB041217: Optical Observations
  77. GRB041217: P60 Optical Observations
  78. GRB041217: Infrared Observations
  79. GRB041217: The First GRB Located On-Board Swift
  80. GRB041211: Faulkes Telescope continued optical monitoring
  81. Optical Transient in Lynx not a GRB
  82. Optical transient (GRB?) in Lynx
  83. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  84. GRB041211: Continued P60 Observations
  85. GRB041211: RAPTOR observations
  86. GRB041211: Ashra Prototype optical observation
  87. GRB041211, Faulkes Telescope optical observation
  88. GRB041211, BVRcIc field calibration
  89. GRB 041211: Infrared Observations
  90. GRB 041211: KAIT observations
  91. GRB 041211: Optical follow-up in East Asian region
  92. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  93. GRB041211: P60 optical imaging
  94. GRB970815: Discovery of Optical Afterglow
  95. Distribution of IBAS Alerts for NON-GRB sources
  96. Triangulation of short GRB 041116 (large error box)
  97. GRB 040924: Afterglow Color
  98. GRB 041006: GETS Optical Afterglow Observation
  99. Summary of the recent bursts from SGR 1806-20
  100. GRB 041006: Optical Observations

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