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

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