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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"
  1. GRB 080430: optical observations
  2. GRB 081008 optical upper limit
  3. GRB 081012: Observations from NOT
  4. GRB 081012: Swift/UVOT analysis of initial observations
  5. GRB 081012: Swift/XRT detection
  6. GRB 081012, Swift-BAT refined analysis
  7. GRB 081012: ROTSE-III Optical Limits
  8. GRB 081012: Swift detection of a burst
  9. Revised table for GRB 081011 UVOT detections
  10. GRB081011: UVOT detection of an optical afterglow
  11. GRB 081011: Swift/XRT detection
  12. GRB 081011, Swift-BAT refined analysis
  13. GRB 081008, SMARTS optical/IR afterglow observations
  14. GRB 081011: Swift detection of a burst
  15. GRB 081007: Radio Detection
  16. Konus-Wind observation of GRB 081001
  17. GRB 081007: Rapid PROMPT Detections
  18. GRB 081008, Swift-BAT refined analysis
  19. GRB 081008: VLT redshift confirmation
  20. GRB 081008: Swift-XRT Refined Analysis
  21. GRB081008: Swift/UVOT observations
  22. GRB 081008: Enhanced Swift-XRT position
  23. GRB 081008: Gemini-South Absorption Redshiftt
  24. GRB 081008: VLT/FORS2 spectroscopy
  25. GRB 081008: Swift detection of a burst with optical afterglow
  26. GRB 081008: ROTSE-III Detection of Optical Counterpart
  27. GRB081006B: Fermi GBM detection
  28. GRB081006: Fermi GBM detection
  29. GRB081007: Swift/UVOT Observations
  30. GRB 081007, SMARTS optical afterglow observations
  31. GRB 081007, Swift-BAT refined analysis
  32. GRB 081007: Early RAPTOR measurements of optical counterpart
  33. GRB 081007: Swift-XRT Team refined analysis
  34. GRB 081007: Gemini-south redshift
  35. GRB 081007: Enhanced Swift-XRT position
  36. GRB 081007, Faulkes Telescope North optical observations
  37. GRB 081007, SMARTS optical/IR afterglow observations
  38. GRB 081007: REM NIR and optical counterpart
  39. GRB 081007: Swift detection of a burst with optical afterglow
  40. GRB081003C: GLAST Burst Monitor detection
  41. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  42. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  43. GRB 081003B: TAROT Calern observatory optical observations
  44. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  45. GRB 081003B: Swift-XRT upper limit
  46. GRB 081003A: OSN optical observations
  47. GRB 081001: Further observations from OSN
  48. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  49. GRB081003B: Optical limits from Spain
  50. GRB 081003A: Swift-XRT Team position and analysis
  51. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  52. GRB 081003B: a long GRB detected with INTEGRAL
  53. GRB 080928: Fermi GBM detection
  54. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  55. GRB 081003: A long GRB discovered by INTEGRAL
  56. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  57. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  58. Trigger 330353: Swift detection of a Galactic short soft burst
  59. GRB 081001: Observations from OSN
  60. GRB 080925: Suzaku WAM observation of the prompt emission
  61. GRB 081001: Swift UVOT Observations
  62. GRB 081001: Swift-XRT position
  63. GRB081001: optical limit from ASH-Centurion
  64. GRB081001: SuperAGILE Localization of a long GRB
  65. GRB080928: redshift retraction
  66. GRB 080928: Watcher observations
  67. GRB 080927: Fermi GBM detection
  68. GRB 080928: VLT redshift
  69. GRB080928: Gemini-South Absorption Redshift
  70. GRB 080928: Swift-XRT refined analysis
  71. GRB 080928: Swift/UVOT observations
  72. GRB 080928, Swift-BAT final refined analysis
  73. GRB 080928: GROND DETECTION
  74. GRB 080928: Enhanced Swift-XRT position
  75. GRB 080928, Swift-BAT initial refined analysis
  76. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  77. GRB 080928: Swift detection of a burst with an optical counterpart
  78. GRB 080925: Fermi GBM Detection
  79. GRB 080920: Fermi GBM detection
  80. GRB080922, optical upper limit
  81. Swift-BAT trigger 325707 is not a GRB
  82. Swift trigger 325707: Swift/UVOT Upper Limits
  83. Swift trigger 325707: Swift-XRT upper limit
  84. Swift detection of a possible GRB (trigger 325707)
  85. GRB080916A: Suzaku WAM observation of the prompt emission
  86. GRB 080922: Swift/UVOT Upper Limits
  87. GRB080922: Swift-XRT upper limit
  88. GRB080922: A long GRB detected by INTEGRAL
  89. GRB 080913B: Fermi GBM detection
  90. Trigger 324561: IGR J08408-4503 detected by Swift
  91. GRB 080916C: Fermi GBM Spectral Analysis
  92. GRB 080919: Swift/UVOT Refined Analysis
  93. GRB 080919: Swift-XRT refined analysis
  94. GRB 080919, Swift-BAT refined analysis
  95. GRB 080916C: IRSF/SIRUS NIR Observation
  96. GRB 080916C: GROND Confirmation of the Optical Afterglow
  97. GRB 080916C: GROND Confirmation of the Optical Afterglow
  98. GRB 080919: REM NIR observations
  99. GRB 080919: Swift detection of a short burst
  100. Fermi/GBM Data Now Available

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