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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 081008: Swift-XRT Refined Analysis
  2. GRB081008: Swift/UVOT observations
  3. GRB 081008: Enhanced Swift-XRT position
  4. GRB 081008: Gemini-South Absorption Redshiftt
  5. GRB 081008: VLT/FORS2 spectroscopy
  6. GRB 081008: Swift detection of a burst with optical afterglow
  7. GRB 081008: ROTSE-III Detection of Optical Counterpart
  8. GRB081006B: Fermi GBM detection
  9. GRB081006: Fermi GBM detection
  10. GRB081007: Swift/UVOT Observations
  11. GRB 081007, SMARTS optical afterglow observations
  12. GRB 081007, Swift-BAT refined analysis
  13. GRB 081007: Early RAPTOR measurements of optical counterpart
  14. GRB 081007: Swift-XRT Team refined analysis
  15. GRB 081007: Gemini-south redshift
  16. GRB 081007: Enhanced Swift-XRT position
  17. GRB 081007, Faulkes Telescope North optical observations
  18. GRB 081007, SMARTS optical/IR afterglow observations
  19. GRB 081007: REM NIR and optical counterpart
  20. GRB 081007: Swift detection of a burst with optical afterglow
  21. GRB081003C: GLAST Burst Monitor detection
  22. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  23. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  24. GRB 081003B: TAROT Calern observatory optical observations
  25. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  26. GRB 081003B: Swift-XRT upper limit
  27. GRB 081003A: OSN optical observations
  28. GRB 081001: Further observations from OSN
  29. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  30. GRB081003B: Optical limits from Spain
  31. GRB 081003A: Swift-XRT Team position and analysis
  32. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  33. GRB 081003B: a long GRB detected with INTEGRAL
  34. GRB 080928: Fermi GBM detection
  35. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  36. GRB 081003: A long GRB discovered by INTEGRAL
  37. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  38. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  39. Trigger 330353: Swift detection of a Galactic short soft burst
  40. GRB 081001: Observations from OSN
  41. GRB 080925: Suzaku WAM observation of the prompt emission
  42. GRB 081001: Swift UVOT Observations
  43. GRB 081001: Swift-XRT position
  44. GRB081001: optical limit from ASH-Centurion
  45. GRB081001: SuperAGILE Localization of a long GRB
  46. GRB080928: redshift retraction
  47. GRB 080928: Watcher observations
  48. GRB 080927: Fermi GBM detection
  49. GRB 080928: VLT redshift
  50. GRB080928: Gemini-South Absorption Redshift
  51. GRB 080928: Swift-XRT refined analysis
  52. GRB 080928: Swift/UVOT observations
  53. GRB 080928, Swift-BAT final refined analysis
  54. GRB 080928: GROND DETECTION
  55. GRB 080928: Enhanced Swift-XRT position
  56. GRB 080928, Swift-BAT initial refined analysis
  57. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  58. GRB 080928: Swift detection of a burst with an optical counterpart
  59. GRB 080925: Fermi GBM Detection
  60. GRB 080920: Fermi GBM detection
  61. GRB080922, optical upper limit
  62. Swift-BAT trigger 325707 is not a GRB
  63. Swift trigger 325707: Swift/UVOT Upper Limits
  64. Swift trigger 325707: Swift-XRT upper limit
  65. Swift detection of a possible GRB (trigger 325707)
  66. GRB080916A: Suzaku WAM observation of the prompt emission
  67. GRB 080922: Swift/UVOT Upper Limits
  68. GRB080922: Swift-XRT upper limit
  69. GRB080922: A long GRB detected by INTEGRAL
  70. GRB 080913B: Fermi GBM detection
  71. Trigger 324561: IGR J08408-4503 detected by Swift
  72. GRB 080916C: Fermi GBM Spectral Analysis
  73. GRB 080919: Swift/UVOT Refined Analysis
  74. GRB 080919: Swift-XRT refined analysis
  75. GRB 080919, Swift-BAT refined analysis
  76. GRB 080916C: IRSF/SIRUS NIR Observation
  77. GRB 080916C: GROND Confirmation of the Optical Afterglow
  78. GRB 080916C: GROND Confirmation of the Optical Afterglow
  79. GRB 080919: REM NIR observations
  80. GRB 080919: Swift detection of a short burst
  81. Fermi/GBM Data Now Available
  82. GRB 080915A: GROND upper limits
  83. GRB080913: Swift-BAT spectral lag
  84. GRB 080916A: GROND lightcurve
  85. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  86. GRB 080916A: Rapid PROMPT Observations
  87. GRB 080916A: Fermi GBM detection
  88. GRB 080916C: Swift UVOT Refined Analysis
  89. GRB 080916C: Swift XRT refined analysis
  90. GRB 080916B: Swift-XRT refined analysis
  91. Konus-Wind observation of GRB 080916A
  92. Konus-Wind observation of GRB 080916C
  93. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  94. GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
  95. GRB 080916C: Enhanced XRT position
  96. GRB080916A: Spectroscopic redshift
  97. GRB 080916C: Swift/XRT detection of possible afterglow
  98. GRB 080916B: Swift UVOT Refined Analysis
  99. IPN Triangulation and Energy Spectrum of GRB080916C
  100. GRB 080916B, Swift-BAT refined analysis

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