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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"

28044 results found.

  1. GRB 081228: Swift detection of a burst
  2. VLA radio observation of GRB 081221
  3. GRB 081226B: Swift XRT and UVOT upper limits
  4. GRB 081224: Suzaku WAM observation of the prompt emission
  5. GRB 081226: Swift-XRT refined analysis
  6. GRB 081226A: Swift UVOT Upper Limits
  7. GRB 081226A: Swift-BAT refined analysis
  8. GRB 081226: GROND afterglow candidate
  9. GRB 081226: ROTSE-III Optical Limits
  10. GRB 081226: Swift detection of a possible short-hard burst
  11. GRB 080810: optical observations
  12. GRB 081211B: optical observations
  13. GRB 081224: Swift-XRT observation
  14. GRB 081222: MITSuME optical observation
  15. GRB 081224: Fermi GBM Detection & LAT Localization
  16. GRB 080810: optical observations
  17. Konus-Wind observation of GRB 081222
  18. GRB 081223: Fermi GBM detection
  19. GRB 081221: GROND observations
  20. VLA radio upper limit on GRB 081222
  21. GRB 081222: Fermi GBM observation
  22. GRB 081221: Probable host galaxy in Keck imaging
  23. GRB 081204C: Fermi GBM detection
  24. GRB 081222, Swift-BAT refined analysis
  25. GRB 081221, Swift-BAT refined analysis
  26. GRB081222 optical limit by "Pi of the Sky"
  27. GRB 081222: Swift XRT refined analysis
  28. GRB081221: Fermi GBM observation
  29. IPN triangulation of bright GRB 081215A
  30. GRB 081222: Faulkes Telescope South observations
  31. GRB 081221: Gemini-N nIR imaging
  32. GRB081222, optical observation
  33. GRB081203A: BTA observation
  34. Konus-Wind observation of GRB 081221
  35. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  36. GRB081222: REM candidate afterglow
  37. GRB 081222: Swift detection of a burst with a bright optical afterglow
  38. GRB 081221: Enhanced Swift-XRT position
  39. GRB 081221: further NOT observations
  40. GRB 081221: NOT observations
  41. GRB 081221: Swift detection of a burst
  42. GRB 081217: Fermi GBM detection
  43. GRB 081211B: Further Swift-XRT analysis
  44. GRB 081215B: Fermi GBM detection
  45. GRB 081216: Suzaku WAM observation of the prompt emission
  46. GRB 081216 : Fermi GBM observation
  47. GRB 081215A: Fermi GBM detection
  48. GRB 081118: Zadko observations
  49. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  50. GRB 0811215A: MASTER prompt optical observations
  51. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  52. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  53. Possible GRB 081211B: Swift/UVOT Upper Limits
  54. GRB 081213: Fermi GBM detection
  55. Possible GRB 081211B - Swift-XRT analysis
  56. GRB 081207: Fermi GBM detection
  57. GRB 081209: Fermi GBM detection
  58. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  59. GRB 081210, SMARTS optical/IR observations
  60. GRB 081211: Swift-BAT refined analysis
  61. GRB 081211: Swift XRT refined analysis
  62. GRB 081211: Enhanced Swift-XRT position
  63. GRB 081211: Swift detection of a burst
  64. GRB 081210: Swift-XRT refined analysis
  65. GRB081203B: optical observations
  66. GRB 081210: Enhanced Swift-XRT position
  67. GRB 081210: Swift-BAT refined analysis
  68. GRB 081210: Swift detection of a burst with optical afterglow
  69. IPN triangulation of short hard GRB 081209
  70. GRB 081203A: optical observations
  71. GRB 081206C: Fermi GBM detection
  72. Radio observation of GRB 081121 with ATCA
  73. Radio observation of GRB 081118 with ATCA
  74. GRB 081206B: Fermi GBM detection
  75. GRB 081206: Fermi GBM detection
  76. GRB 081128: afterglow observations
  77. GRB 081203B: Suzaku WAM observation of the prompt emission
  78. Radio observation of GRB 081109 with ATCA
  79. Radio observation of GRB 081104 with ATCA
  80. Radio observation of GRB 081029 with ATCA
  81. Radio observation of GRB 081008 with ATCA
  82. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  83. GRB081203A: Optical observations at Ishigaki
  84. GRB 081204: GROND Observations
  85. Radio detection of GRB 081203B with the VLA
  86. GRB081203A: Radio upper limit at 15 GHz
  87. GRB 081204B: Fermi GBM detection
  88. GRB 081204: Swift/UVOT Upper Limits
  89. GRB 081204: Swift XRT afterglow confirmation
  90. GRB081203A: MITSuME optical observation
  91. GRB081203A: optical observation
  92. GRB 081204 : a long GRB localized by INTEGRAL
  93. VLA Radio upper limit on GRB 081203A
  94. Swift-XRT observations of GRB 081203B
  95. GRB081203A: Swift-XRT refined analysis
  96. GRB 081203B: optical observations
  97. Swift/UVOT detection of GRB081203B
  98. GRB 081203B: Swift-XRT candidate afterglow.
  99. GRB 081203A: optical observations
  100. GRB081203A: Swift/UVOT grism redshift

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