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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 081007: Early RAPTOR measurements of optical counterpart
  2. GRB 081007: Swift-XRT Team refined analysis
  3. GRB 081007: Gemini-south redshift
  4. GRB 081007: Enhanced Swift-XRT position
  5. GRB 081007, Faulkes Telescope North optical observations
  6. GRB 081007, SMARTS optical/IR afterglow observations
  7. GRB 081007: REM NIR and optical counterpart
  8. GRB 081007: Swift detection of a burst with optical afterglow
  9. GRB081003C: GLAST Burst Monitor detection
  10. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  11. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  12. GRB 081003B: TAROT Calern observatory optical observations
  13. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  14. GRB 081003B: Swift-XRT upper limit
  15. GRB 081003A: OSN optical observations
  16. GRB 081001: Further observations from OSN
  17. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  18. GRB081003B: Optical limits from Spain
  19. GRB 081003A: Swift-XRT Team position and analysis
  20. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  21. GRB 081003B: a long GRB detected with INTEGRAL
  22. GRB 080928: Fermi GBM detection
  23. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  24. GRB 081003: A long GRB discovered by INTEGRAL
  25. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  26. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  27. Trigger 330353: Swift detection of a Galactic short soft burst
  28. GRB 081001: Observations from OSN
  29. GRB 080925: Suzaku WAM observation of the prompt emission
  30. GRB 081001: Swift UVOT Observations
  31. GRB 081001: Swift-XRT position
  32. GRB081001: optical limit from ASH-Centurion
  33. GRB081001: SuperAGILE Localization of a long GRB
  34. GRB080928: redshift retraction
  35. GRB 080928: Watcher observations
  36. GRB 080927: Fermi GBM detection
  37. GRB 080928: VLT redshift
  38. GRB080928: Gemini-South Absorption Redshift
  39. GRB 080928: Swift-XRT refined analysis
  40. GRB 080928: Swift/UVOT observations
  41. GRB 080928, Swift-BAT final refined analysis
  42. GRB 080928: GROND DETECTION
  43. GRB 080928: Enhanced Swift-XRT position
  44. GRB 080928, Swift-BAT initial refined analysis
  45. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  46. GRB 080928: Swift detection of a burst with an optical counterpart
  47. GRB 080925: Fermi GBM Detection
  48. GRB 080920: Fermi GBM detection
  49. GRB080922, optical upper limit
  50. Swift-BAT trigger 325707 is not a GRB
  51. Swift trigger 325707: Swift/UVOT Upper Limits
  52. Swift trigger 325707: Swift-XRT upper limit
  53. Swift detection of a possible GRB (trigger 325707)
  54. GRB080916A: Suzaku WAM observation of the prompt emission
  55. GRB 080922: Swift/UVOT Upper Limits
  56. GRB080922: Swift-XRT upper limit
  57. GRB080922: A long GRB detected by INTEGRAL
  58. GRB 080913B: Fermi GBM detection
  59. Trigger 324561: IGR J08408-4503 detected by Swift
  60. GRB 080916C: Fermi GBM Spectral Analysis
  61. GRB 080919: Swift/UVOT Refined Analysis
  62. GRB 080919: Swift-XRT refined analysis
  63. GRB 080919, Swift-BAT refined analysis
  64. GRB 080916C: IRSF/SIRUS NIR Observation
  65. GRB 080916C: GROND Confirmation of the Optical Afterglow
  66. GRB 080916C: GROND Confirmation of the Optical Afterglow
  67. GRB 080919: REM NIR observations
  68. GRB 080919: Swift detection of a short burst
  69. Fermi/GBM Data Now Available
  70. GRB 080915A: GROND upper limits
  71. GRB080913: Swift-BAT spectral lag
  72. GRB 080916A: GROND lightcurve
  73. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  74. GRB 080916A: Rapid PROMPT Observations
  75. GRB 080916A: Fermi GBM detection
  76. GRB 080916C: Swift UVOT Refined Analysis
  77. GRB 080916C: Swift XRT refined analysis
  78. GRB 080916B: Swift-XRT refined analysis
  79. Konus-Wind observation of GRB 080916A
  80. Konus-Wind observation of GRB 080916C
  81. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  82. GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
  83. GRB 080916C: Enhanced XRT position
  84. GRB080916A: Spectroscopic redshift
  85. GRB 080916C: Swift/XRT detection of possible afterglow
  86. GRB 080916B: Swift UVOT Refined Analysis
  87. IPN Triangulation and Energy Spectrum of GRB080916C
  88. GRB 080916B, Swift-BAT refined analysis
  89. GRB080916A: Refined Swift/UVOT Observations
  90. GRB 080915a, SMARTS optical/IR observations
  91. GRB 080916B: Enhanced Swift-XRT position
  92. GRB 080916C: Fermi LAT observation
  93. GRB 080916C: Fermi GBM Detection
  94. GRB 080916A: Swift XRT refined analysis
  95. GRB 080916A, Swift-BAT refined analysis
  96. GRB 080916B: Swift-XRT afterglow detection
  97. GRB 080916A: Enhanced Swift-XRT position
  98. GRB 080916B: Swift detection of a burst
  99. GRB 080916: REM detection of the NIR afterglow
  100. GRB 080916: REM candidate afterglow

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