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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"

25841 results found.

  1. GRB090107B: Fermi GBM Detection
  2. GRB 090107B: Swift XRT afterglow confirmation
  3. GRB 090107B: Swift/UVOT Observations
  4. GRB 090107B: Swift-XRT detection of possible afterglow
  5. Fermi/GBM detection of GRB 081226A
  6. Fermi/GBM detection of GRB 081225
  7. GRB 081231: Fermi GBM Detection
  8. VLA radio upper limit on GRB 090102
  9. GRB 090102: GRT Optical Observation
  10. Swift triggered on the HMXB 1A 1118-61
  11. Konus-Wind observation of GRB 090102
  12. GRB 081229: Fermi GBM detection
  13. GRB 090102: P60 Imaging and P200 Spectroscopy
  14. GRB 090102 Observations from IAC80
  15. GRB 090102: GROND observations of the optical afterglow
  16. GRB 090102: Swift-BAT refined analysis
  17. GRB 090102: Swift XRT refined analysis
  18. GRB 090102: NOT redshift
  19. GRB 090102: Enhanced Swift-XRT position
  20. GRB 090102: REM observations of a bright afterglow
  21. GRB 090102: Swift detection of a burst with an optical counterpart
  22. GRB 090102: TAROT Calern observatory optical observations
  23. GRB 081230: GROND confirmation of the afterglow
  24. GRB081230: Swift-XRT refined analysis
  25. GRB 081230 Swift/UVOT Observations
  26. GRB 081230: Enhanced Swift-XRT position
  27. GRB 081230: Swift detection of a burst
  28. GRB 081226B: Fermi GBM observation
  29. GRB 081226C: Fermi GBM detection
  30. GRB 081228, Swift-BAT refined analysis
  31. VLA radio detection of GRB 081221
  32. GRB 081228: Swift/UVOT Upper Limits
  33. GRB 081228: Swift-XRT Team refined analysis
  34. GRB 081228: detection by GROND
  35. GRB 081228: Enhanced Swift-XRT position
  36. GRB 081228: TAROT Calern observatory optical observations
  37. GRB 081228: Swift detection of a burst
  38. VLA radio observation of GRB 081221
  39. GRB 081226B: Swift XRT and UVOT upper limits
  40. GRB 081224: Suzaku WAM observation of the prompt emission
  41. GRB 081226: Swift-XRT refined analysis
  42. GRB 081226A: Swift UVOT Upper Limits
  43. GRB 081226: GROND afterglow candidate
  44. GRB 081226: ROTSE-III Optical Limits
  45. GRB 081226: Swift detection of a possible short-hard burst
  46. GRB 080810: optical observations
  47. GRB 081211B: optical observations
  48. GRB 081224: Swift-XRT observation
  49. GRB 081222: MITSuME optical observation
  50. GRB 081224: Fermi GBM Detection & LAT Localization
  51. GRB 081223: Fermi GBM detection
  52. GRB 081221: GROND observations
  53. VLA radio upper limit on GRB 081222
  54. GRB 081222: Fermi GBM observation
  55. GRB 081221: Probable host galaxy in Keck imaging
  56. GRB 081204C: Fermi GBM detection
  57. GRB 081222, Swift-BAT refined analysis
  58. GRB081222 optical limit by "Pi of the Sky"
  59. GRB 081222: Swift XRT refined analysis
  60. GRB081221: Fermi GBM observation
  61. IPN triangulation of bright GRB 081215A
  62. GRB 081221: Swift-XRT Refined Analysis
  63. GRB 081222: Faulkes Telescope South observations
  64. GRB 081221: Gemini-N nIR imaging
  65. GRB081222, optical observation
  66. GRB081203A: BTA observation
  67. Konus-Wind observation of GRB 081221
  68. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  69. GRB081222: REM candidate afterglow
  70. GRB 081222: Swift detection of a burst with a bright optical afterglow
  71. GRB 081221: Enhanced Swift-XRT position
  72. GRB 081221: further NOT observations
  73. GRB 081221: NOT observations
  74. GRB 081221: Swift detection of a burst
  75. GRB 081217: Fermi GBM detection
  76. GRB 081211B: Further Swift-XRT analysis
  77. GRB 081215B: Fermi GBM detection
  78. GRB 081216: Suzaku WAM observation of the prompt emission
  79. GRB 081216 : Fermi GBM observation
  80. GRB 081215A: Fermi GBM detection (correction to event fluence)
  81. GRB 081215A: Fermi GBM detection
  82. GRB 081118: Zadko observations
  83. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  84. GRB 0811215A: MASTER prompt optical observations
  85. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  86. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  87. Possible GRB 081211B: Swift/UVOT Upper Limits
  88. GRB 081213: Fermi GBM detection
  89. Possible GRB 081211B - Swift-XRT analysis
  90. GRB 081207: Fermi GBM detection
  91. GRB 081209: Fermi GBM detection
  92. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  93. GRB 081210, SMARTS optical/IR observations
  94. GRB 081211: Swift XRT refined analysis
  95. GRB 081211: Enhanced Swift-XRT position
  96. GRB 081211: Swift detection of a burst
  97. GRB 081210: Swift-XRT refined analysis
  98. GRB081203B: optical observations
  99. GRB 081210: Enhanced Swift-XRT position
  100. GRB 081210: Swift detection of a burst with optical afterglow

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