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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. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  2. GRB 081003B: Swift-XRT upper limit
  3. GRB 081003A: OSN optical observations
  4. GRB 081001: Further observations from OSN
  5. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  6. GRB081003B: Optical limits from Spain
  7. GRB 081003A: Swift-XRT Team position and analysis
  8. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  9. GRB 081003B: a long GRB detected with INTEGRAL
  10. GRB 080928: Fermi GBM detection
  11. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  12. GRB 081003: A long GRB discovered by INTEGRAL
  13. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  14. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  15. Trigger 330353: Swift detection of a Galactic short soft burst
  16. GRB 081001: Observations from OSN
  17. GRB 080925: Suzaku WAM observation of the prompt emission
  18. GRB 081001: Swift UVOT Observations
  19. GRB 081001: Swift-XRT position
  20. GRB081001: optical limit from ASH-Centurion
  21. GRB081001: SuperAGILE Localization of a long GRB
  22. GRB080928: redshift retraction
  23. GRB 080928: Watcher observations
  24. GRB 080927: Fermi GBM detection
  25. GRB 080928: VLT redshift
  26. GRB080928: Gemini-South Absorption Redshift
  27. GRB 080928: Swift-XRT refined analysis
  28. GRB 080928: Swift/UVOT observations
  29. GRB 080928, Swift-BAT final refined analysis
  30. GRB 080928: GROND DETECTION
  31. GRB 080928: Enhanced Swift-XRT position
  32. GRB 080928, Swift-BAT initial refined analysis
  33. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  34. GRB 080928: Swift detection of a burst with an optical counterpart
  35. GRB 080925: Fermi GBM Detection
  36. GRB 080920: Fermi GBM detection
  37. GRB080922, optical upper limit
  38. Swift-BAT trigger 325707 is not a GRB
  39. Swift trigger 325707: Swift/UVOT Upper Limits
  40. Swift trigger 325707: Swift-XRT upper limit
  41. Swift detection of a possible GRB (trigger 325707)
  42. GRB080916A: Suzaku WAM observation of the prompt emission
  43. GRB 080922: Swift/UVOT Upper Limits
  44. GRB080922: Swift-XRT upper limit
  45. GRB080922: A long GRB detected by INTEGRAL
  46. GRB 080913B: Fermi GBM detection
  47. Trigger 324561: IGR J08408-4503 detected by Swift
  48. GRB 080916C: Fermi GBM Spectral Analysis
  49. GRB 080919: Swift/UVOT Refined Analysis
  50. GRB 080919: Swift-XRT refined analysis
  51. GRB 080919, Swift-BAT refined analysis
  52. GRB 080916C: IRSF/SIRUS NIR Observation
  53. GRB 080916C: GROND Confirmation of the Optical Afterglow
  54. GRB 080916C: GROND Confirmation of the Optical Afterglow
  55. GRB 080919: REM NIR observations
  56. GRB 080919: Swift detection of a short burst
  57. Fermi/GBM Data Now Available
  58. GRB 080915A: GROND upper limits
  59. GRB080913: Swift-BAT spectral lag
  60. GRB 080916A: GROND lightcurve
  61. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  62. GRB 080916A: Rapid PROMPT Observations
  63. GRB 080916A: Fermi GBM detection
  64. GRB 080916C: Swift UVOT Refined Analysis
  65. GRB 080916C: Swift XRT refined analysis
  66. GRB 080916B: Swift-XRT refined analysis
  67. Konus-Wind observation of GRB 080916A
  68. Konus-Wind observation of GRB 080916C
  69. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  70. GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
  71. GRB 080916C: Enhanced XRT position
  72. GRB080916A: Spectroscopic redshift
  73. GRB 080916C: Swift/XRT detection of possible afterglow
  74. GRB 080916B: Swift UVOT Refined Analysis
  75. IPN Triangulation and Energy Spectrum of GRB080916C
  76. GRB 080916B, Swift-BAT refined analysis
  77. GRB080916A: Refined Swift/UVOT Observations
  78. GRB 080915a, SMARTS optical/IR observations
  79. GRB 080916B: Enhanced Swift-XRT position
  80. GRB 080916C: Fermi LAT observation
  81. GRB 080916C: Fermi GBM Detection
  82. GRB 080916A: Swift XRT refined analysis
  83. GRB 080916A, Swift-BAT refined analysis
  84. GRB 080916B: Swift-XRT afterglow detection
  85. GRB 080916A: Enhanced Swift-XRT position
  86. GRB 080916B: Swift detection of a burst
  87. GRB 080916: REM detection of the NIR afterglow
  88. GRB 080916: REM candidate afterglow
  89. GRB 080916: Swift detection of a burst with optical afterglow
  90. GRB 080915B, Swift-BAT refined analysis
  91. GRB 080912 : Fermi GBM detection
  92. GRB 080915B: Swift detection of a burst
  93. GRB 080915: REM NIR early observations
  94. GRB 080915: Swift/UVOT Upper Limits
  95. GRB 080915: Swift-XRT afterglow detection and analysis
  96. GRB 080915, Swift-BAT refined analysis
  97. SGR 0501+4516 : P200 i-band observations
  98. GRB 080915: ROTSE-III Optical Limits
  99. GRB 080915: Swift detection of a burst
  100. GRB 080913: Swift-XRT refined analysis

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