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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"

28092 results found.

  1. GRB 1000302A : A possible afterglow candidate
  2. GRB 100302A: Enhanced Swift-XRT position
  3. GRB 100302A: Skynet/DAO Observations
  4. GRB 100302A: Swift detection of a burst
  5. GRB 100224B: Fermi GBM detection
  6. GRB 100206A: optical observations in CrAO
  7. GRB 100206A: optical observations in Terskol
  8. GRB 100213B: Mondy optical observations
  9. GRB 100219A: optical observations
  10. GRB 100224A SHB found in ground analysis of BAT data
  11. GRB 100225A: Fermi LAT detection
  12. GRB 100225A: Fermi GBM detection
  13. GRB 100223A: Fermi GBM detection
  14. GRB
  15. GRB 100219A: XRT refined analysis
  16. GRB100219A Akeno and Okayama MITSuME Optical Observation
  17. GRB 100219A: GROND observations
  18. GRB 100219A: NOT OA observations
  19. GRB 100219A: Enhanced Swift-XRT position
  20. GRB 100219A: Swift/UVOT Detection of the Optical Afterglow
  21. GRB 100216A: XRT Refined Analysis
  22. GRB 100219A: Swift-BAT refined analysis
  23. GRB 100219A: Pre-explosion imaging and host candidate
  24. GRB 100219A: Swift/UVOT Detection of a Source near the XRT Position
  25. GRB 100218A : Fermi GBM detection
  26. GRB 100219A: Swift detection of a burst
  27. GRB 100216A: Keck imaging
  28. GRB 100213B: GRT Optical Observation
  29. GRB 100213A: GRT Optical Observation
  30. GRB 100213A: Swift-BAT refined analysis
  31. GRB 100213B: Enhanced Swift-XRT position
  32. GRB 100213B: Gemini-N Observations
  33. GRB 100213B: Swift/UVOT Upper Limits
  34. GRB 100213A: Swift/UVOT Upper Limits
  35. GRB 100213B: PAIRITEL NIR Upper Limits
  36. GRB 100213A: Enhanced Swift-XRT position
  37. GRB 100213B: Swift-BAT refined analysis
  38. GRB 100213B: Swift XRT refined analysis
  39. GRB 100213A: SARA observations
  40. GRB 100213A: Swift XRT refined analysis
  41. GRB 100213B: NOT optical observations
  42. GRB 100213B: Swift detection of a burst
  43. GRB 100213A: Swift detection of a burst
  44. Swift/UVOT observations of GRB120212A
  45. GRB 100212A: Fermi GBM detection
  46. GRB 100212A: Swift XRT refined analysis
  47. GRB 100212A: Swift-BAT refined analysis
  48. GRB 100212A: Enhanced Swift-XRT position
  49. GRB 100212A: candidate optical afterglow
  50. GRB 100212A: Swift detection of a burst
  51. GRB 091127: Detection of a Supernova
  52. GRB 100205A: Keck limits on an underlying host galaxy
  53. GRB 100205A: BOAO/LOAO zYJK observation
  54. GRB 100205B: Fermi GBM detection
  55. GRB 100206A: GROND upper limits
  56. GRB 100206A: Gemini-North observations
  57. GRB 100206A: Swift/UVOT Upper Limits
  58. GRB 100131A: MASTER-Net optical alert observations
  59. GRB 100206A: YNAO-GMG observations
  60. GRB 100206A: MASTER-Net optical alert observations
  61. GRB 100206A: PAIRITEL Photometry of Host Candidate
  62. GRB100206: MITSuME optical upper limits
  63. GRB 100206A: NOT NIR observations
  64. GRB 100206A, RIMOTS optical upper limits
  65. GRB 100205A: GROND upper limits
  66. GRB 100206A: Swift-XRT refined analysis
  67. GRB 100206A: Optical limit
  68. GRB 100206A: Swift-BAT refined analysis
  69. GRB 100206A: Enhanced Swift-XRT position
  70. GRB 100206A: Pre-explosion imaging and host candidate
  71. GRB 100206A: Swift detection of a short hard burst
  72. GRB100205A: CFHT z'-band observation
  73. GRB 100205A: Gemini-N + NIRI photometry
  74. GRB 100130B: Fermi GBM detection
  75. GRB 100113A: Fermi GBM detection
  76. GRB 100205A: Swift-BAT refined analysis
  77. GRB 100205A: Swift UVOT upper limits
  78. GRB 100205A: Swift XRT refined analysis
  79. GRB 100203A: Swift XRT and UVOT refined analyses
  80. GRB 100205A: Enhanced Swift-XRT position
  81. GRB 100205A Gemini-North IR afterglow candidate
  82. GRB 100205A: Gemini-South Observations
  83. GRB 100205A: Super-LOTIS early observations
  84. GRB 100131A: Suzaku WAM observation of the prompt emission
  85. GRB 100205A: NOT optical observations
  86. GRB 100205A: Swift detection of a burst
  87. Short X-ray Transient detected by MAXI/GSC
  88. GRB 100131A: Fermi GBM detection
  89. GRB 100119A: Suzaku WAM observation of the prompt emission
  90. GRB 100122A: Fermi GBM detection
  91. GRB 100122A: MASTER-Net optical observations
  92. GRB 100116A: Suzaku WAM observation of the prompt emission
  93. GRB 100115A: Swift-XRT refined analysis
  94. GRB 100119A: Swift-BAT refined analysis
  95. Swift/UVOT refined analysis of GRB100117A
  96. GRB 100117A: Swift-XRT refined analysis
  97. GRB 100117A: Gemini-North upper limit
  98. GRB 100117A: Magellan IMACS imaging
  99. GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
  100. GRB 100117A: Swift-BAT refined analysis

Advanced

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