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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"

20498 results found.

  1. GRB 090418B: Faulkes Telescope North observations
  2. GRB 090418A: Swift/UVOT Observations
  3. GRB 090417B: Swift/UVOT Upper Limits
  4. GRB 090419: Swift-XRT refined analysis
  5. Konus-Wind observation of GRB 090418B
  6. GRB 090419: GROND detection of afterglow candidate
  7. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  8. VLA radio detection of GRB 090418
  9. VLA radio upper limit on GRB 090417B
  10. GRB 090419: Enhanced Swift-XRT position
  11. GRB 090418A: ROTSE-III Refined Analysis
  12. GRB 090419: Swift detection of a burst
  13. VLA observations of short burst GRB 090417A
  14. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  15. GRB 090417B: Gemini imaging
  16. GRB 090418: Swift-BAT refined analysis
  17. GRB 090418: Enhanced Swift-XRT position
  18. GRB 090418: Swift detection of a burst with optical afterglow
  19. GRB 090411B: Suzaku WAM observation of the prompt emission
  20. GRB 090411A: Suzaku WAM observation of the prompt emission
  21. GRB 090417B: Subaru NIR Observations
  22. GRB 090417B: MITSuME Okayama optical upper limits
  23. GRB 090417B: optical observations
  24. GRB090417B: optical observations
  25. GRB 090417B: Swift detection of a burst
  26. GRB 090410: Suzaku WAM observation of the prompt emission
  27. GRB 090410: GROND upper limits
  28. GRB 090410: MITSuME optical upper limits
  29. GRB 090408b: IPN Triangulation
  30. GRB 090328b: IPN Triangulation
  31. GRB090408, RIMOTS optical upper limits
  32. Swift-BAT trigger 348781: almost certainly not a burst
  33. GRB 090408B: MASTER II-Kourovka optical observations
  34. GRB 090407: GROND upper limits
  35. GRB 090407: VLT observations
  36. GRB 090407: Swift UVOT Upper Limits
  37. GRB 090407: Enhanced Swift-XRT position
  38. Konus-Wind and Konus-RF observations of GRB 090406
  39. GRB 090407: ROTSE-III Optical Limits
  40. GRB 090407: Swift detection of a burst
  41. GRB 090404: GROND upper limits
  42. GRB 090404: further NOT observations
  43. Swift/UVOT observations of GRB090404
  44. GRB 090404: NOT observations
  45. GRB 090404: Enhanced Swift-XRT position
  46. GRB 090404: Swift detection of a burst
  47. GRB 090401A: Suzaku WAM observation of the prompt emission
  48. GRB 090401B: Suzaku WAM observation of the prompt emission
  49. Konus-Wind observation of GRB 090401B
  50. GRB 090401B: VLA radio upper limit
  51. GRB 090401B: Upper limits of MITSuME optical observation
  52. GRB090401B, RIMOTS optical upper limits
  53. GRB 090401B: AGILE refined analysis
  54. Konus-Wind observation of GRB 090401A
  55. GRB 090401B: Enhanced Swift-XRT position
  56. AGILE Gamma-ray detection of GRB 090401B
  57. GRB 090401B: Swift-BAT refined analysis
  58. GRB 090401B: Swift detection of a burst
  59. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  60. GRB 090401, Swift-BAT refined analysis
  61. GRB 090324: Suzaku WAM observation of the prompt emission
  62. GRB 090328: Radio afterglow detection
  63. GRB 090328: Fermi GBM Spectral Analysis
  64. GRB 090328B: Fermi GBM Detection
  65. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  66. GRB090323: Optical observations from NOT
  67. Konus-Wind observation of GRB 090328
  68. GRB 090328: Swift UVOT observations
  69. GRB 090328: Updated position/optical afterglow candidate
  70. Fermi LAT and GBM detections of GRB090328
  71. GRB 090323: Radio afterglow detection
  72. GRB 090323: TLS detection at 5 days, no break
  73. GRB 090320B: MASTER-Net prompt optical observations
  74. GRB 090323: Lick observations
  75. GRB 090323: Fermi GBM Spectral Analysis
  76. GRB 090323: UVOT Detection of Afterglow
  77. GRB 090323: P60 Afterglow Confirmation
  78. GRB 090323: GROND Detection of the Afterglow and Photo-z
  79. GRB 090323: Possible XRT Counterpart
  80. Fermi GBM and LAT detections of GRB 090323
  81. Further 15GHz observations of GRB090313
  82. X-shooter observations of GRB 090313
  83. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  84. GRB 090315: Suzaku WAM observation of the prompt emission
  85. GRB090313: radio detection with the VLA
  86. Konus-Wind observation of GRB 090315
  87. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  88. Further radio observation of GRB 090313
  89. GRB 090313: detection with CARMA in 3mm band
  90. GRB090305B: MASTER-net prompt optical short burst observations
  91. GRB 090313: MITSuME Okayama observation
  92. GRB 090313: Additional Gemini-S photometry
  93. GRB 090313: TAROT La Silla observatory optical detection
  94. GRB 090313: Zadko Telescope observations
  95. GRB 090313: Ongoing plateau phase
  96. GRB 090313: Swift-XRT refined analysis
  97. GRB 090313: Swift/UVOT upper limits
  98. GRB 090313, GROND observations
  99. Swift trigger 346250 is probably not a burst
  100. GRB 090205: Zadko Telescope late-time observations

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