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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"

14832 results found.

  1. GRB 090520D: Fermi GBM detection
  2. GRB 090520C: Fermi GBM detection
  3. GRB 090520B: Fermi GBM detection
  4. GRB 090522 : Fermi GBM detection
  5. GRB 090524: Fermi GBM detection
  6. GRB 090513B: Fermi GBM detection
  7. GRB 090518: Fermi GBM detection
  8. GRB 090516C: Fermi GBM detection
  9. GRB 090520 Swift-BAT detection of a burst in ground analysis
  10. GRB 090423: Fermi GBM T90 follow-up analysis results
  11. GRB 090516B: Fermi GBM detection
  12. GRB 090519B: Fermi GBM detection
  13. GRB 090519: Swift detection of a burst
  14. GRB 090511: Fermi GBM Detection
  15. GRB 090514: Fermi GBM detection
  16. GRB 090518B: Fermi GBM detection
  17. GRB090513: Fermi GBM detection
  18. GRB 090518: Swift detection of a burst
  19. GRB 090516: Swift-BAT refined analysis
  20. GRB 090516: Swift detection of a burst
  21. GRB 090515: ROVOR Upper Limit
  22. GRB 090515: Swift detection of a short burst
  23. GRB090510: VLT/FORS2 spectroscopic redshift
  24. GRB 090510: GROND observations
  25. GRB 090510B: Fermi GBM detection
  26. GRB 090502: Fermi GBM detection
  27. AGILE detection of GRB 090510
  28. GRB 090510: Fermi GBM detection
  29. Fermi LAT detection of GRB 090510
  30. GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
  31. GRB 090510: Swift detection of a short hard burst
  32. GRB 090509: Swift detection of a burst
  33. GRB 090323: optical observations
  34. GRB 090423: optical limit
  35. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  36. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  37. GRB 090429A: ROVOR magnitude limit
  38. GRB 090429D: Fermi GBM detection
  39. GRB 090429C: Fermi GBM detection
  40. GRB 090427C: Fermi GBM detection
  41. GRB 090427B: Fermi GBM detection
  42. GRB 090426C: Fermi GBM detection
  43. GRB 090426B: Fermi GBM detection/observation
  44. GRB 090428B: Fermi GBM detection
  45. GRB 090428: Fermi GBM detection
  46. GRB 090429B: Swift detection of a burst
  47. GRB 090429: Swift detection of a burst
  48. GRB 090423: millimeter detection
  49. GRB 090425: Fermi GBM detection
  50. GRB 090426: VLT spectroscopy
  51. GRB090426 Swift/UVOT observations
  52. Detection of bright radio afterglow of GRB 090424 with the VLA
  53. GRB 090426: Swift detection of a burst with an optical counterpart
  54. GRB090424: R-band detection (37.5 hrs post-burst), jet break?
  55. GRB090424: BVRI/R-band detection after 15 hrs burst
  56. GRB 090424 : TAOS optical detection
  57. GRB 090424 optical observations
  58. GRB 090424: Swift detection of a burst with an optical counterpart
  59. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  60. GRB 090423: GROND detection and preliminary photo-z
  61. GRB 090423: Correction to NIR photometry
  62. GRB 090423: NIR photometry and evidence for spectral break
  63. GRB 090423: Swift detection of a burst
  64. GRB 090422: Swift detection of a burst
  65. GRB 090418C: Fermi GBM Detection
  66. GRB 090418A: Swift/UVOT Detection of the Neighbouring Galaxy
  67. GRB 090419: Swift/UVOT Observations
  68. GRB 090418A: Swift/UVOT Observations
  69. GRB 090419: GROND detection of afterglow candidate
  70. VLA radio detection of GRB 090418
  71. GRB 090418A: ROTSE-III Refined Analysis
  72. GRB 090419: Swift detection of a burst
  73. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  74. GRB 090418: PAIRITEL NIR detection
  75. GRB 090418: Swift detection of a burst with optical afterglow
  76. GRB 090417B: Swift detection of a burst
  77. GRB 090417: Swift detection of a short burst
  78. GRB 090412: Fermi GBM detection
  79. GRB 090411B: Fermi GBM detection
  80. GRB 090411A: Fermi GBM detection
  81. GRB 090410: Swift detection of a burst
  82. GRB 090409: Fermi GBM detection
  83. Swift-BAT trigger 348781: almost certainly not a burst
  84. Fermi GBM Detection of a weak source
  85. GRB 090408: Swift detection of a burst
  86. GRB 090407: Swift detection of a burst
  87. GRB 090404: millimeter detection
  88. GRB 090404: nIR observations at Calar Alto
  89. GRB 090405: Fermi GBM Detection
  90. GRB 090403: Fermi GBM detection
  91. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  92. GRB 090404: Swift detection of a burst
  93. GRB 090401B: AGILE refined analysis
  94. GRB 090331: Fermi GBM detection
  95. AGILE Gamma-ray detection of GRB 090401B
  96. Swift/UVOT detection of GRB090401B
  97. GRB 090401B: Swift detection of a burst
  98. GRB 090323: Further TLS detections - a break?
  99. GRB 090401: Swift detection of a burst
  100. GRB 090328: Radio afterglow detection

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