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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  2. GRB 041219c: PROMPT Observations
  3. GRB041223: ROTSE-III Optical Observations
  4. GRB041223: Swift-BAT detection of a bright long burst
  5. GRB 041218: optical observations
  6. Very high activity of SGR 1806-20
  7. GRB 041219: Second Epoch WSRT Radio Observations
  8. GRB 041219: WSRT Radio Afterglow Detection
  9. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  10. GRB 041218: Optical observations
  11. GRB 041219 : optical follow-up observations
  12. GRB041220: Swift-BAT burst
  13. Deep RAPTOR observations during GRB 041219
  14. GRB 041218 Optical Observations
  15. GRB 041219 Optical Observations
  16. GRB041219c: Third Burst in One Day from Swift-BAT
  17. GRB041219: Optical Afterglow Detection
  18. GRB041219: Continued NIR Observations
  19. GRB041219b: A Swift-BAT burst
  20. GRB 041219 ,optical observation
  21. GRB 041219: Radio Afterglow Detection
  22. GRB 041218 : Radio Observations
  23. GRB 041218: R-band optical observations
  24. GRB041218: Liverpool Telescope optical observations
  25. GRB041218: optical observations
  26. GRB041219: Confirmed NIR Afterglow
  27. GRB041218: Continued P60 Optical Observations
  28. Swift-BAT detection of the bright long burst GRB041219
  29. GRB 041218: Optical Observation
  30. GRB 041219: Infrared Afterglow Candidate
  31. GRB041219, BVRcIc field calibration
  32. GRB 041219: Infrared Afterglow Candidate
  33. GRB041218, BVRcIc field calibration
  34. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  35. GRB041219: P60 Optical Observations
  36. GRB 041219 - A long GRB detected by INTEGRAL
  37. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  38. GRB 041217: PROMPT Observations
  39. GRB041218: optical observations
  40. GRB041217: optical limit 30 min after GRB
  41. GRB 041218; optical candidate
  42. GRB 041218: Optical observations
  43. GRB 041217: LCO40 Optical Observations and Possible Candidates
  44. GRB 041218 - A long GRB detected by integral
  45. GRB041217: Optical Observations
  46. GRB041217: NIR and optical observations with REM
  47. GRB041217: P60 Optical Observations
  48. GRB041217: Infrared Observations
  49. GRB041217: The First GRB Located On-Board Swift
  50. GRB041211: Faulkes Telescope continued optical monitoring
  51. Optical Transient in Lynx not a GRB
  52. Optical transient (GRB?) in Lynx
  53. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  54. GRB041211: Continued P60 Observations
  55. GRB041211: RAPTOR observations
  56. GRB041211: Ashra Prototype optical observation
  57. GRB041211, Faulkes Telescope optical observation
  58. GRB041211, BVRcIc field calibration
  59. GRB041211,optical observation
  60. GRB 041211: Infrared Observations
  61. GRB 041211: KAIT observations
  62. GRB 041211: Optical follow-up in East Asian region
  63. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  64. GRB041211: P60 optical imaging
  65. GRB970815: Discovery of Optical Afterglow
  66. Distribution of IBAS Alerts for NON-GRB sources
  67. Triangulation of short GRB 041116 (large error box)
  68. GRB041015: Near-Infrared observations
  69. GRB 040924: Afterglow Color
  70. GRB 041006: GETS Optical Afterglow Observation
  71. Summary of the recent bursts from SGR 1806-20
  72. GRB 041006: Optical Observations
  73. GRB041006, late-time optical photometry
  74. GRB041015, optical observation in CrAO
  75. IBAS GRB Alert # 2034
  76. GRB041006: RTT150 Optical Observations
  77. GRB041015 : Multi epoch optical observations
  78. HST Observations: XRF 040701 and 040812
  79. Bright bursts from SGR1806-20
  80. GRB 041016: BOOTES-2 simultaneous observation
  81. GRB041006: RTT150 Optical Observations
  82. GRB041016,optical observation
  83. GRB 041016: Optical limits
  84. GRB 041016: Optical limits in V, R, I
  85. GRB 041016:Optical limit during first minute
  86. GRB041016: MASTER: Optical observations
  87. GRB 041015: Optical Observations at Rikubetsu
  88. GRB041006: Near Infrared observations
  89. GRB 041016: Optical limit
  90. GRB 041015 R band observations
  91. GRB040924, BVRcIc field calibration
  92. GRB041015: MASTER: Optical observations
  93. GRB041015,optical observation
  94. GRB041006: Fading X-ray Afterglow Observed with Chandra
  95. GRB 041015: Optical limit at Osaka University
  96. GRB041015 : Optical follow-up at Kiso
  97. GRB 041015 - A long GRB detected by INTEGRAL
  98. GRB 041006 R observations in Loiano
  99. GRB041006: VLT observations of the afterglow and host galaxy
  100. GRB041006: Optical observations and Potential host galaxy

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