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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"

6667 results found.

  1. GRB 100224B: Fermi GBM detection
  2. GRB 100225A: Fermi LAT detection
  3. GRB 100225A: Fermi GBM detection
  4. GRB 100223A: Fermi GBM detection
  5. GRB 100219A: XRT refined analysis
  6. GRB 100216A: Swift/UVOT Observations
  7. GRB 100216A: XRT Refined Analysis
  8. GRB 100213B: PAIRITEL NIR Upper Limits
  9. GRB 100213B: Swift XRT refined analysis
  10. GRB 100212A: Swift XRT refined analysis
  11. GRB 100206A: PAIRITEL Photometry of Host Candidate
  12. GRB 100206A: NOT NIR observations
  13. GRB 100206A: Swift-XRT refined analysis
  14. GRB 100205A: Swift XRT refined analysis
  15. GRB 100203A: Swift XRT and UVOT refined analyses
  16. Short X-ray Transient detected by MAXI/GSC
  17. GRB 100115A: Swift-XRT refined analysis
  18. GRB 100117A: Swift-XRT refined analysis
  19. GRB 100116A: Fermi LAT detection
  20. GRB 100115A: Swift-XRT candidate afterglow
  21. GRB 100111A: PAIRITEL NIR Upper Limits
  22. GRB 100103A: Swift-XRT team refined analysis
  23. GRB 100103A: Swift/XRT position
  24. Swift Trigger 381591 is probably not a burst
  25. GRB 091230: Swift-XRT observation
  26. Swift Trigger 381434 is not a GRB
  27. GRB 091221 : IRSF NIR upper limit
  28. GRB 091117: Swift-XRT late time observations
  29. GRB 091221: Swift-XRT refined analysis
  30. GRB 091221: Enhanced Swift-XRT position
  31. Swift trigger 379449 (possible GRB) is not a burst
  32. GRB091208A: Swift/UVOT refined analysis
  33. GRB 091208A: Swift-XRT observations
  34. GRB 091208B: Swift-XRT refined analysis
  35. GRB091202: Swift-XRT refined analysis
  36. GRB 091130B: Swift-XRT team refined analysis
  37. Swift trigger 377436 (possible GRB 091130A) is not a burst
  38. GRB 091127: Radio observations
  39. GRB 091127: Swift-XRT afterglow detection and analysis
  40. GRB 091117: Swift-XRT observations
  41. GRB 091117: Evidence for Variability of XRT Source #1
  42. GRB 091117: Swift XRT refined analysis
  43. GRB091111: Swift XRT refined analysis
  44. GRB 091031: Fermi LAT detection of a faint burst
  45. GRB 091109B: Swift-XRT Team refined analysis
  46. GRB 091109: Swift-XRT refined analysis
  47. GRB 091104: Swift XRT Refined Analysis
  48. GRB091026 : IRSF NIR upper limit
  49. Fermi LAT Upper Limits on GRB 091010
  50. GRB 091102: Swift-XRT refined analysis
  51. GRB 091024: Fermi LAT upper limits
  52. GRB 091029: Swift XRT refined analysis
  53. GRB091024 optical observations
  54. GRB 091026: Swift/UVOT Upper Limits
  55. GRB 091026: Swift-XRT refined analysis
  56. GRB 091020: Early TLS Multicolor detections, red afterglow
  57. GRB091024: VRcIc Afterglow Observations
  58. GRB 091024: Fermi GBM Observations
  59. GRB 091024: Swift-XRT team refined analysis
  60. GRB 091020: Swift-XRT refined analysis
  61. GRB 091018: Swift XRT refined analysis
  62. GRB 091018: miniTAO/ANIR Observations
  63. GRB 090726 R band observations
  64. GRB 091010: Swift-XRT refined analysis
  65. GRB 091010: Swift-XRT position
  66. GRB 091003: Swift-XRT confirmation of fading afterglow
  67. GRB 091003: Swift XRT analysis
  68. GRB 091003A: Fermi LAT detection
  69. GRB 090929A: Swift-XRT non-detection
  70. GRB 090929B: Swift-XRT refined analysis
  71. GRB 090926A: Fermi LAT and GBM refined analysis
  72. GRB090926A: Swift-XRT refined analysis
  73. GRB 090926: Fermi LAT detection
  74. GRB090904B : IRSF NIR upper limit
  75. GRB 090916: Swift-XRT upper limit
  76. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  77. GRB 090827: Confirmation of the X-ray afterglow
  78. GRB 090912: Swift-XRT refined analysis
  79. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  80. GRB 090904A: Swift-XRT refined analysis
  81. GRB 090904B: Swift XRT Refined Analysis
  82. GRB 090904A: Enhanced Swift XRT position
  83. GRB090902B: Swift XRT refined analysis
  84. GRB 090902B: Fermi LAT and GBM refined analysis.
  85. GRB 090902B: Enhanced Swift-XRT position
  86. GRB 090902B: Fermi LAT detection
  87. Swift Trigger 361477, called GRB090831B, is probably not real.
  88. GRB 090831C: Swift XRT Refined Analysis
  89. GRB 090827: Swift XRT and UVOT observations
  90. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  91. GRB 090817: No host galaxy, no supernova
  92. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  93. GRB 090817: Confirmation of the X-ray afterglow
  94. GRB 090815C: Swift refined analysis
  95. GRB 090817: Swift-XRT observations
  96. GRB 090814B: Confirmation of the X-ray afterglow
  97. GRB 090814B: I-band observations from 1.23m CAHA telescope
  98. GRB 090814B: Swift/UVOT Upper Limits
  99. GRB 090814B: Swift-XRT detection of a possible afterglow.
  100. GRB 090814A: Swift-XRT Team Refined Analysis

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