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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 081012, Swift-BAT refined analysis
  2. GRB 081012: ROTSE-III Optical Limits
  3. GRB 081012: Swift detection of a burst
  4. Revised table for GRB 081011 UVOT detections
  5. GRB081011: UVOT detection of an optical afterglow
  6. GRB 081011: Swift/XRT detection
  7. GRB 081011, Swift-BAT refined analysis
  8. GRB 081008, SMARTS optical/IR afterglow observations
  9. GRB 081011: Swift detection of a burst
  10. GRB 081007: Radio Detection
  11. Konus-Wind observation of GRB 081001
  12. GRB 081007: Rapid PROMPT Detections
  13. GRB 081008, Swift-BAT refined analysis
  14. GRB 081008: VLT redshift confirmation
  15. GRB 081008: Swift-XRT Refined Analysis
  16. GRB081008: Swift/UVOT observations
  17. GRB 081008: Enhanced Swift-XRT position
  18. GRB 081008: Gemini-South Absorption Redshiftt
  19. GRB 081008: VLT/FORS2 spectroscopy
  20. GRB 081008: Swift detection of a burst with optical afterglow
  21. GRB 081008: ROTSE-III Detection of Optical Counterpart
  22. GRB081006B: Fermi GBM detection
  23. GRB081006: Fermi GBM detection
  24. GRB081007: Swift/UVOT Observations
  25. GRB 081007, SMARTS optical afterglow observations
  26. GRB 081007, Swift-BAT refined analysis
  27. GRB 081007: Early RAPTOR measurements of optical counterpart
  28. GRB 081007: Swift-XRT Team refined analysis
  29. GRB 081007: Gemini-south redshift
  30. GRB 081007: Enhanced Swift-XRT position
  31. GRB 081007, Faulkes Telescope North optical observations
  32. GRB 081007, SMARTS optical/IR afterglow observations
  33. GRB 081007: REM NIR and optical counterpart
  34. GRB 081007: Swift detection of a burst with optical afterglow
  35. GRB081003C: GLAST Burst Monitor detection
  36. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  37. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  38. GRB 081003B: TAROT Calern observatory optical observations
  39. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  40. GRB 081003B: Swift-XRT upper limit
  41. GRB 081003A: OSN optical observations
  42. GRB 081001: Further observations from OSN
  43. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  44. GRB081003B: Optical limits from Spain
  45. GRB 081003A: Swift-XRT Team position and analysis
  46. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  47. GRB 081003B: a long GRB detected with INTEGRAL
  48. GRB 080928: Fermi GBM detection
  49. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  50. GRB 081003: A long GRB discovered by INTEGRAL
  51. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  52. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  53. Trigger 330353: Swift detection of a Galactic short soft burst
  54. GRB 081001: Observations from OSN
  55. GRB 080925: Suzaku WAM observation of the prompt emission
  56. GRB 081001: Swift UVOT Observations
  57. GRB 081001: Swift-XRT position
  58. GRB081001: optical limit from ASH-Centurion
  59. GRB081001: SuperAGILE Localization of a long GRB
  60. GRB080928: redshift retraction
  61. GRB 080928: Watcher observations
  62. GRB 080927: Fermi GBM detection
  63. GRB 080928: VLT redshift
  64. GRB080928: Gemini-South Absorption Redshift
  65. GRB 080928: Swift-XRT refined analysis
  66. GRB 080928: Swift/UVOT observations
  67. GRB 080928, Swift-BAT final refined analysis
  68. GRB 080928: GROND DETECTION
  69. GRB 080928: Enhanced Swift-XRT position
  70. GRB 080928, Swift-BAT initial refined analysis
  71. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  72. GRB 080928: Swift detection of a burst with an optical counterpart
  73. GRB 080925: Fermi GBM Detection
  74. GRB 080920: Fermi GBM detection
  75. GRB080922, optical upper limit
  76. Swift-BAT trigger 325707 is not a GRB
  77. Swift trigger 325707: Swift/UVOT Upper Limits
  78. Swift trigger 325707: Swift-XRT upper limit
  79. Swift detection of a possible GRB (trigger 325707)
  80. GRB080916A: Suzaku WAM observation of the prompt emission
  81. GRB 080922: Swift/UVOT Upper Limits
  82. GRB080922: Swift-XRT upper limit
  83. GRB080922: A long GRB detected by INTEGRAL
  84. GRB 080913B: Fermi GBM detection
  85. Trigger 324561: IGR J08408-4503 detected by Swift
  86. GRB 080916C: Fermi GBM Spectral Analysis
  87. GRB 080919: Swift/UVOT Refined Analysis
  88. GRB 080919: Swift-XRT refined analysis
  89. GRB 080919, Swift-BAT refined analysis
  90. GRB 080916C: IRSF/SIRUS NIR Observation
  91. GRB 080916C: GROND Confirmation of the Optical Afterglow
  92. GRB 080916C: GROND Confirmation of the Optical Afterglow
  93. GRB 080919: REM NIR observations
  94. GRB 080919: Swift detection of a short burst
  95. Fermi/GBM Data Now Available
  96. GRB 080915A: GROND upper limits
  97. GRB080913: Swift-BAT spectral lag
  98. GRB 080916A: GROND lightcurve
  99. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  100. GRB 080916A: Rapid PROMPT Observations

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