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

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