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

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