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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"

5050 results found.

  1. GRB 090424: THO optical observations
  2. GRB090423: Y-band limit
  3. GRB 090424 optical observations
  4. GRB 090424: Swift-XRT refined analysis
  5. GRB 090424: Fermi GBM Observation
  6. GRB 090423: Swift-XRT refined analysis
  7. GRB090418A Rc-band photometry
  8. GRB090423, RIMOTS optical upper limits
  9. GRB 090418A: optical observations
  10. GRB 090418A: Swift/UVOT Observations
  11. GRB 090419: Swift-XRT refined analysis
  12. VLA radio detection of GRB 090418
  13. GRB 090418: Swift XRT refined analysis
  14. GRB 090418: Swift-BAT refined analysis
  15. GRB 090418: Enhanced Swift-XRT position
  16. GRB 090418: Swift detection of a burst with optical afterglow
  17. GRB 090418 OA candidate
  18. GRB 090408b: IPN Triangulation
  19. GRB 090328b: IPN Triangulation
  20. GRB 090407: GROND upper limits
  21. GRB 090407: Swift-XRT refined analysis
  22. GRB 090404: Swift-XRT Team refined analysis
  23. GRB 090401A: Suzaku WAM observation of the prompt emission
  24. GRB 090401B: Swift XRT Refined Analysis
  25. GRB 090328: Radio afterglow detection
  26. GRB 090328B: Fermi GBM Detection
  27. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  28. GRB 090323: WSRT Radio Detection
  29. GRB 090327: Fermi GBM detection
  30. GRB 090320B: MASTER-Net prompt optical observations
  31. GRB 090323: Swift-XRT refined analysis
  32. GRB 090324: SuperAGILE Localization of a Long GRB
  33. GRB 090323 Gemini-South Redshift
  34. GRB 090323: P60 Afterglow Confirmation
  35. GRB 090323: GROND Detection of the Afterglow and Photo-z
  36. SGR J1550-5418: two Fermi GBM triggers on March 22
  37. GRB 090319: Fermi GBM detection
  38. GRB 090315: Suzaku WAM observation of the prompt emission
  39. GRB 090313: MITSuME Okayama observation
  40. GRB 090309: Swift-XRT refined analysis
  41. GRB 090308: Swift-XRT refined analysis
  42. GRB 090306B: Possible XRT afterglow
  43. Swift-BAT trigger 345396 is not a GRB
  44. GRB 090306: Swift detection of a possible burst
  45. IPN localization of short bright GRB 090227B
  46. SGR J1550-5418
  47. GRB 081211B: Nearby cluster
  48. GRB 090222: Fermi GBM detection
  49. GRB 090217: Suzaku WAM observation of the prompt emission
  50. IPN localization of GRB 090217
  51. GRB 090126A: Swift-XRT Refined Analysis
  52. GRB 090123: GROND detection
  53. GRB 090123: Swift XRT refined analysis
  54. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  55. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  56. GRB 090118: Swift-XRT observations
  57. GRB 090113: Swift-XRT refined analysis
  58. GRB 090111: Swift-XRT refined analysis
  59. GRB 090102: WSRT Radio Observations
  60. GRB081230: Swift-XRT refined analysis
  61. GRB 081228: Swift-XRT Team refined analysis
  62. GRB 081228: TAROT Calern observatory optical observations
  63. GRB 081224: Suzaku WAM observation of the prompt emission
  64. GRB 081224: Fermi GBM Detection & LAT Localization
  65. GRB 081222, Swift-BAT refined analysis
  66. GRB 081222: Swift XRT refined analysis
  67. GRB081221: Fermi GBM observation
  68. GRB 081221: Gemini-N nIR imaging
  69. GRB 081221: further NOT observations
  70. GRB 081221: NOT observations
  71. Modification of Swift/UVOT response to bright GRBs
  72. GRB 081216: Suzaku WAM observation of the prompt emission
  73. GRB 081211: Swift XRT refined analysis
  74. GRB 081210: Swift-XRT refined analysis
  75. Radio observation of GRB 081121 with ATCA
  76. Radio observation of GRB 081118 with ATCA
  77. GRB 081206: Fermi GBM detection
  78. Radio observation of GRB 081109 with ATCA
  79. Radio observation of GRB 081104 with ATCA
  80. Radio observation of GRB 081029 with ATCA
  81. Radio observation of GRB 081008 with ATCA
  82. GRB 081204B: Fermi GBM detection
  83. GRB 081204: Swift XRT afterglow confirmation
  84. GRB081203A: Swift-XRT refined analysis
  85. GRB 081203A: optical observations
  86. VLA Radio upper limit on GRB 081126
  87. GRB 081128: Swift-XRT refined analysis
  88. GRB 081127: Swift-XRT refined analysis
  89. GRB 081126: Swift-XRT refined analysis
  90. GRB 081125: Fermi GBM detection
  91. GRB 081124: Fermi GBM detection
  92. GRB 081118: Fermi GBM detection.
  93. GRB 081122: Fermi GBM detection
  94. GRB 081121: GROND observations
  95. GRB 081118: Swift-XRT refined analysis
  96. GRB 081102: MASTER refind and final results
  97. GRB 081109B: Swift/UVOT refined analysis
  98. GRB 081109A: Swift-XRT refined analysis
  99. GRB 081024C: Fermi Gamma-ray Burst Monitor detection
  100. GRB 081104: refined XRT analysis

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