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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"

19548 results found.

  1. GRB 090102: Enhanced Swift-XRT position
  2. GRB 090102: REM observations of a bright afterglow
  3. GRB 090102: Swift detection of a burst with an optical counterpart
  4. GRB 090102: TAROT Calern observatory optical observations
  5. GRB 081230: GROND confirmation of the afterglow
  6. GRB081230: Swift-XRT refined analysis
  7. GRB 081230 Swift/UVOT Observations
  8. GRB 081230: Enhanced Swift-XRT position
  9. GRB 081230: Swift detection of a burst
  10. GRB 081226B: Fermi GBM observation
  11. GRB 081226C: Fermi GBM detection
  12. GRB 081228, Swift-BAT refined analysis
  13. VLA radio detection of GRB 081221
  14. GRB 081228: Swift/UVOT Upper Limits
  15. GRB 081228: Swift-XRT Team refined analysis
  16. GRB 081228: detection by GROND
  17. GRB 081228: Enhanced Swift-XRT position
  18. GRB 081228: TAROT Calern observatory optical observations
  19. GRB 081228: Swift detection of a burst
  20. VLA radio observation of GRB 081221
  21. GRB 081226B: Swift XRT and UVOT upper limits
  22. GRB 081226: Swift-XRT refined analysis
  23. GRB 081226A: Swift UVOT Upper Limits
  24. GRB 081226A: Swift-BAT refined analysis
  25. GRB 081226: GROND afterglow candidate
  26. GRB 081226: ROTSE-III Optical Limits
  27. GRB 081226: Swift detection of a possible short-hard burst
  28. GRB 080810: optical observations
  29. GRB 081211B: optical observations
  30. GRB 081224: Swift-XRT observation
  31. GRB 081222: MITSuME optical observation
  32. GRB 081223: Fermi GBM detection
  33. GRB 081221: GROND observations
  34. VLA radio upper limit on GRB 081222
  35. GRB 081222: Fermi GBM observation
  36. GRB 081221: Probable host galaxy in Keck imaging
  37. GRB 081204C: Fermi GBM detection
  38. GRB 081222, Swift-BAT refined analysis
  39. GRB081222 optical limit by "Pi of the Sky"
  40. GRB 081222: Swift XRT refined analysis
  41. GRB081221: Fermi GBM observation
  42. IPN triangulation of bright GRB 081215A
  43. GRB 081222: Faulkes Telescope South observations
  44. GRB 081221: Gemini-N nIR imaging
  45. GRB081222, optical observation
  46. GRB081203A: BTA observation
  47. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  48. GRB081222: REM candidate afterglow
  49. GRB 081222: Swift detection of a burst with a bright optical afterglow
  50. GRB 081221: Enhanced Swift-XRT position
  51. GRB 081221: further NOT observations
  52. GRB 081221: NOT observations
  53. GRB 081221: Swift detection of a burst
  54. GRB 081217: Fermi GBM detection
  55. GRB081215A: Fermi-LAT observations
  56. GRB 081211B: Further Swift-XRT analysis
  57. GRB 081215A: Fermi GBM detection (correction to event fluence)
  58. GRB 081215A: Fermi GBM detection
  59. GRB 081118: Zadko observations
  60. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  61. GRB 0811215A: MASTER prompt optical observations
  62. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  63. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  64. Possible GRB 081211B: Swift/UVOT Upper Limits
  65. Possible GRB 081211B - Swift-XRT analysis
  66. GRB 081209: Fermi GBM detection
  67. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  68. GRB 081210, SMARTS optical/IR observations
  69. GRB 081211: Enhanced Swift-XRT position
  70. GRB 081211: Swift detection of a burst
  71. GRB081203B: optical observations
  72. GRB 081210: Enhanced Swift-XRT position
  73. GRB 081210: Swift-BAT refined analysis
  74. GRB 081210: Swift detection of a burst with optical afterglow
  75. IPN triangulation of short hard GRB 081209
  76. GRB 081203A: optical observations
  77. GRB 081206: Fermi GBM detection
  78. GRB 081128: afterglow observations
  79. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  80. GRB081203A: Optical observations at Ishigaki
  81. GRB 081204: GROND Observations
  82. Radio detection of GRB 081203B with the VLA
  83. GRB081203A: Radio upper limit at 15 GHz
  84. GRB 081204B: Fermi GBM detection
  85. GRB 081204: Swift/UVOT Upper Limits
  86. GRB081203A: MITSuME optical observation
  87. GRB081203A: optical observation
  88. VLA Radio upper limit on GRB 081203A
  89. GRB 081203B: optical observations
  90. Swift/UVOT detection of GRB081203B
  91. GRB 081203B: Swift-XRT candidate afterglow.
  92. GRB 081203A: optical observations
  93. GRB 081203: Enhanced Swift-XRT position
  94. GRB 081130B: MASTER prompt optical observations
  95. GRB081203: optical observation
  96. GRB 081203: Swift detection of a burst with a bright optical counterpart
  97. GRB 081128: optical observation
  98. Swift Trigger 335971: Swift/UVOT Observations
  99. GRB 081126: afterglow photometry
  100. GRB 081126: Fermi GBM detection

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