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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.

Advanced Search Examples (click to copy):

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

3402 results found.

  1. GRB 091117: Swift-XRT late time observations
  2. GRB 091221: Swift-XRT refined analysis
  3. GRB 091221: Enhanced Swift-XRT position
  4. Swift trigger 379449 (possible GRB) is not a burst
  5. GRB091208A: Swift/UVOT refined analysis
  6. GRB 091208A: Swift-XRT observations
  7. GRB 091208B: Swift-XRT refined analysis
  8. GRB091202: Swift-XRT refined analysis
  9. Konus-Wind observation of very long GRB 091123
  10. GRB 091130B: Swift-XRT team refined analysis
  11. Swift trigger 377436 (possible GRB 091130A) is not a burst
  12. GRB 091127: Swift-XRT afterglow detection and analysis
  13. GRB 091117: Swift-XRT observations
  14. GRB 091117: Evidence for Variability of XRT Source #1
  15. GRB 091117: Swift XRT refined analysis
  16. GRB091111: Swift XRT refined analysis
  17. GRB 091109B: Swift-XRT Team refined analysis
  18. GRB 091109: Swift-XRT refined analysis
  19. GRB 091104: Swift XRT Refined Analysis
  20. GRB091026 : IRSF NIR upper limit
  21. GRB 091102: Swift-XRT refined analysis
  22. GRB 091026: Swift-XRT refined analysis
  23. GRB 091024: Swift-XRT team refined analysis
  24. GRB 091020: Swift-XRT refined analysis
  25. GRB 091018: Swift XRT refined analysis
  26. GRB 091018: miniTAO/ANIR Observations
  27. GRB 091010: Swift-XRT refined analysis
  28. GRB 091010: Swift-XRT position
  29. GRB 091003: Swift-XRT confirmation of fading afterglow
  30. GRB 091003: Swift XRT analysis
  31. GRB 090929A: Swift-XRT non-detection
  32. GRB 090929B: Swift-XRT refined analysis
  33. GRB090926A: Swift-XRT refined analysis
  34. GRB090904B : IRSF NIR upper limit
  35. GRB 090916: Swift-XRT upper limit
  36. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  37. GRB 090827: Confirmation of the X-ray afterglow
  38. GRB 090912: Swift-XRT refined analysis
  39. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  40. GRB 090904A: Swift-XRT refined analysis
  41. GRB 090904B: Swift XRT Refined Analysis
  42. GRB 090904A: Enhanced Swift XRT position
  43. GRB090902B: Swift XRT refined analysis
  44. GRB 090902B: Enhanced Swift-XRT position
  45. Swift Trigger 361477, called GRB090831B, is probably not real.
  46. GRB 090831C: Swift XRT Refined Analysis
  47. GRB 090827: Swift XRT and UVOT observations
  48. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  49. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  50. GRB 090817: Confirmation of the X-ray afterglow
  51. GRB 090815C: Swift refined analysis
  52. GRB 090817: Swift-XRT observations
  53. GRB 090814B: Confirmation of the X-ray afterglow
  54. GRB 090814B: Swift/UVOT Upper Limits
  55. GRB 090814B: Swift-XRT detection of a possible afterglow.
  56. GRB 090814A: Swift-XRT Team Refined Analysis
  57. GRB 090813: Swift-XRT refined analysis
  58. GRB 090812: Swift XRT refined analysis
  59. GRB 090809: Swift-XRT refined analysis
  60. GRB 090807: Swift-XRT refined analysis
  61. GRB 090728: Swift XRT refined analysis
  62. GRB 090727: Swift-XRT refined analysis
  63. GRB 090726: Swift-XRT Team refined analysis
  64. GRB 090715B: break in the optical afterglow decay
  65. GRB 090715B: Swift XRT Refined Analysis
  66. GRB 090709A: Swift XRT Refined Analysis
  67. GRB 090709A - PAIRITEL Discovery of a Red Afterglow
  68. GRB 090709: PAIRITEL NIR Upper Limits
  69. Possible GRB090705: Swift-XRT observations
  70. GRB 090705: PAIRITEL NIR Observations
  71. XRF 090702: Swift-XRT refined analysis
  72. GRB 090628: Swift XRT refined analysis
  73. GRB 090625B: Swift-XRT refined analysis
  74. PAIRITEL observations of GRB 090618
  75. GRB 090621B: Swift-XRT refined analysis
  76. GRB 090621: Swift-XRT Team refined analysis
  77. GRB090618: Swift-XRT team refined analysis
  78. Swift XRT observations of GRB 090531A
  79. RXTE Discovery of Pulsations from SGR 0418+5729
  80. GRB 090607: XRT Team Refined Analysis
  81. GRB090530: Swift XRT refined analysis
  82. GRB 090529: Swift-XRT refined analysis
  83. GRB 090530: PAIRITEL NIR Detections
  84. GRB 090519: Swift-XRT refined analysis
  85. GRB 090518: Swift-XRT refined analysis
  86. GRB 090516: Swift XRT refined analysis
  87. GRB 090515: Swift-XRT refined analysis
  88. GRB 090510: Swift/UVOT host galaxy candidates
  89. GRB 090510: Swift XRT refined analysis
  90. GRB 090429A: Swift-XRT refined analysis
  91. GRB 090429B: Swift XRT refined analysis
  92. GRB 090426: Near infrared observation with ISLE at OAO
  93. GRB 090426: Swift-XRT refined analysis
  94. GRB 090424: Swift-XRT refined analysis
  95. GRB 090423: Near infrared observation at Okayama Observatory
  96. GRB 090423: Swift-XRT refined analysis
  97. GRB 090422: Swift-XRT refined analysis
  98. GRB 090419: Swift-XRT refined analysis
  99. GRB 090418: Swift XRT refined analysis
  100. GRB 090417B: Swift-XRT refined analysis

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Download all Circulars as a .tar.gz archive (updated once a day):
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