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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"

28097 results found.

  1. GRB 090113: Enhanced Swift-XRT position
  2. GRB 090113: Swift-BAT refined analysis
  3. GRB 090113: ROTSE-III Optical Limits
  4. GRB 090112B: Fermi GBM Detection
  5. GRB 090113: Swift detection of a burst
  6. GRB 090112: Fermi GBM detection
  7. GRB 090109: Fermi GBM detection
  8. GRB 090108B: Fermi GBM detection
  9. GRB 090111, Swift-BAT refined analysis
  10. GRB 090111: Swift UVOT Upper Limits
  11. GRB 090108: Fermi GBM Detection
  12. GRB 090111: Swift-XRT refined analysis
  13. GRB 090111: Enhanced Swift-XRT position
  14. GRB 090111: Swift detection of a burst
  15. GRB 090107B: Suzaku WAM observation of the prompt emission
  16. GRB090107B: Fermi GBM Detection
  17. GRB 090107B: Swift XRT afterglow confirmation
  18. GRB 090107B: Swift/UVOT Observations
  19. GRB 090107B: Swift-XRT detection of possible afterglow
  20. GRB 090107B: a long GRB localized by INTEGRAL
  21. Fermi/GBM detection of GRB 081226A
  22. Fermi/GBM detection of GRB 081225
  23. GRB 090107: Swift-BAT refined analysis
  24. GRB 081231: Fermi GBM Detection
  25. VLA radio upper limit on GRB 090102
  26. GRB 090102: GRT Optical Observation
  27. Swift triggered on the HMXB 1A 1118-61
  28. GRB 081229: Fermi GBM detection
  29. GRB 090102: P60 Imaging and P200 Spectroscopy
  30. GRB 090102 Observations from IAC80
  31. GRB 090102: GROND observations of the optical afterglow
  32. GRB 090102: Swift-BAT refined analysis
  33. GRB 090102: Swift XRT refined analysis
  34. GRB 090102: NOT redshift
  35. GRB 090102: Enhanced Swift-XRT position
  36. GRB 090102: REM observations of a bright afterglow
  37. GRB 090102: Swift detection of a burst with an optical counterpart
  38. GRB 090102: TAROT Calern observatory optical observations
  39. GRB 081230: GROND confirmation of the afterglow
  40. GRB 081230, Swift-BAT refined analysis
  41. GRB081230: Swift-XRT refined analysis
  42. GRB 081230 Swift/UVOT Observations
  43. GRB 081230: Enhanced Swift-XRT position
  44. GRB 081230: ROTSE-III Detection of Optical Counterpart
  45. GRB 081230: Swift detection of a burst
  46. GRB 081226C: Fermi GBM detection
  47. GRB 081228, Swift-BAT refined analysis
  48. VLA radio detection of GRB 081221
  49. GRB 081228: Swift/UVOT Upper Limits
  50. GRB 081228: Swift-XRT Team refined analysis
  51. GRB 081228: detection by GROND
  52. GRB 081228: Enhanced Swift-XRT position
  53. GRB 081228: TAROT Calern observatory optical observations
  54. GRB 081228: Swift detection of a burst
  55. VLA radio observation of GRB 081221
  56. GRB 081226B: Swift XRT and UVOT upper limits
  57. GRB 081224: Suzaku WAM observation of the prompt emission
  58. GRB 081226: Swift-XRT refined analysis
  59. GRB 081226A: Swift UVOT Upper Limits
  60. GRB 081226A: Swift-BAT refined analysis
  61. GRB 081226: GROND afterglow candidate
  62. GRB 081226: ROTSE-III Optical Limits
  63. GRB 081226: Swift detection of a possible short-hard burst
  64. GRB 080810: optical observations
  65. GRB 081211B: optical observations
  66. GRB 081224: Swift-XRT observation
  67. GRB 081222: MITSuME optical observation
  68. GRB 081224: Fermi GBM Detection & LAT Localization
  69. GRB 080810: optical observations
  70. Konus-Wind observation of GRB 081222
  71. GRB 081223: Fermi GBM detection
  72. GRB 081221: GROND observations
  73. VLA radio upper limit on GRB 081222
  74. GRB 081222: Fermi GBM observation
  75. GRB 081221: Probable host galaxy in Keck imaging
  76. GRB 081204C: Fermi GBM detection
  77. GRB 081222, Swift-BAT refined analysis
  78. GRB 081221, Swift-BAT refined analysis
  79. GRB081222 optical limit by "Pi of the Sky"
  80. GRB 081222: Swift XRT refined analysis
  81. GRB081221: Fermi GBM observation
  82. IPN triangulation of bright GRB 081215A
  83. GRB 081222: Faulkes Telescope South observations
  84. GRB 081221: Gemini-N nIR imaging
  85. GRB081222, optical observation
  86. GRB081203A: BTA observation
  87. Konus-Wind observation of GRB 081221
  88. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  89. GRB081222: REM candidate afterglow
  90. GRB 081222: Swift detection of a burst with a bright optical afterglow
  91. GRB 081221: Enhanced Swift-XRT position
  92. GRB 081221: further NOT observations
  93. GRB 081221: NOT observations
  94. GRB 081221: Swift detection of a burst
  95. GRB 081217: Fermi GBM detection
  96. GRB 081211B: Further Swift-XRT analysis
  97. GRB 081215B: Fermi GBM detection
  98. GRB 081216: Suzaku WAM observation of the prompt emission
  99. GRB 081216 : Fermi GBM observation
  100. GRB 081215A: Fermi GBM detection

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