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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. GRB081006B: Fermi GBM detection
  2. GRB081006: Fermi GBM detection
  3. GRB081007: Swift/UVOT Observations
  4. GRB 081007, SMARTS optical afterglow observations
  5. GRB 081007, Swift-BAT refined analysis
  6. GRB 081007: Early RAPTOR measurements of optical counterpart
  7. GRB 081007: Swift-XRT Team refined analysis
  8. GRB 081007: Gemini-south redshift
  9. GRB 081007: Enhanced Swift-XRT position
  10. GRB 081007, Faulkes Telescope North optical observations
  11. GRB 081007, SMARTS optical/IR afterglow observations
  12. GRB 081007: REM NIR and optical counterpart
  13. GRB 081007: Swift detection of a burst with optical afterglow
  14. GRB081003C: GLAST Burst Monitor detection
  15. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  16. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  17. GRB 081003B: TAROT Calern observatory optical observations
  18. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  19. GRB 081003B: Swift-XRT upper limit
  20. GRB 081003A: OSN optical observations
  21. GRB 081001: Further observations from OSN
  22. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  23. GRB081003B: Optical limits from Spain
  24. GRB 081003A: Swift-XRT Team position and analysis
  25. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  26. GRB 081003B: a long GRB detected with INTEGRAL
  27. GRB 080928: Fermi GBM detection
  28. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  29. GRB 081003: A long GRB discovered by INTEGRAL
  30. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  31. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  32. Trigger 330353: Swift detection of a Galactic short soft burst
  33. GRB 081001: Observations from OSN
  34. GRB 080925: Suzaku WAM observation of the prompt emission
  35. GRB 081001: Swift UVOT Observations
  36. GRB 081001: Swift-XRT position
  37. GRB081001: optical limit from ASH-Centurion
  38. GRB081001: SuperAGILE Localization of a long GRB
  39. GRB080928: redshift retraction
  40. GRB 080928: Watcher observations
  41. GRB 080927: Fermi GBM detection
  42. GRB 080928: VLT redshift
  43. GRB080928: Gemini-South Absorption Redshift
  44. GRB 080928: Swift-XRT refined analysis
  45. GRB 080928: Swift/UVOT observations
  46. GRB 080928, Swift-BAT final refined analysis
  47. GRB 080928: GROND DETECTION
  48. GRB 080928: Enhanced Swift-XRT position
  49. GRB 080928, Swift-BAT initial refined analysis
  50. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  51. GRB 080928: Swift detection of a burst with an optical counterpart
  52. GRB 080925: Fermi GBM Detection
  53. GRB 080920: Fermi GBM detection
  54. GRB080922, optical upper limit
  55. Swift-BAT trigger 325707 is not a GRB
  56. Swift trigger 325707: Swift/UVOT Upper Limits
  57. Swift trigger 325707: Swift-XRT upper limit
  58. Swift detection of a possible GRB (trigger 325707)
  59. GRB080916A: Suzaku WAM observation of the prompt emission
  60. GRB 080922: Swift/UVOT Upper Limits
  61. GRB080922: Swift-XRT upper limit
  62. GRB080922: A long GRB detected by INTEGRAL
  63. GRB 080913B: Fermi GBM detection
  64. Trigger 324561: IGR J08408-4503 detected by Swift
  65. GRB 080916C: Fermi GBM Spectral Analysis
  66. GRB 080919: Swift/UVOT Refined Analysis
  67. GRB 080919: Swift-XRT refined analysis
  68. GRB 080919, Swift-BAT refined analysis
  69. GRB 080916C: IRSF/SIRUS NIR Observation
  70. GRB 080916C: GROND Confirmation of the Optical Afterglow
  71. GRB 080916C: GROND Confirmation of the Optical Afterglow
  72. GRB 080919: REM NIR observations
  73. GRB 080919: Swift detection of a short burst
  74. Fermi/GBM Data Now Available
  75. GRB 080915A: GROND upper limits
  76. GRB080913: Swift-BAT spectral lag
  77. GRB 080916A: GROND lightcurve
  78. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  79. GRB 080916A: Rapid PROMPT Observations
  80. GRB 080916A: Fermi GBM detection
  81. GRB 080916C: Swift UVOT Refined Analysis
  82. GRB 080916C: Swift XRT refined analysis
  83. GRB 080916B: Swift-XRT refined analysis
  84. Konus-Wind observation of GRB 080916A
  85. Konus-Wind observation of GRB 080916C
  86. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  87. GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
  88. GRB 080916C: Enhanced XRT position
  89. GRB080916A: Spectroscopic redshift
  90. GRB 080916C: Swift/XRT detection of possible afterglow
  91. GRB 080916B: Swift UVOT Refined Analysis
  92. IPN Triangulation and Energy Spectrum of GRB080916C
  93. GRB 080916B, Swift-BAT refined analysis
  94. GRB080916A: Refined Swift/UVOT Observations
  95. GRB 080915a, SMARTS optical/IR observations
  96. GRB 080916B: Enhanced Swift-XRT position
  97. GRB 080916C: Fermi LAT observation
  98. GRB 080916C: Fermi GBM Detection
  99. GRB 080916A: Swift XRT refined analysis
  100. GRB 080916A, Swift-BAT refined analysis

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