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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"

25779 results found.

  1. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  2. GRB 090117C: Suzaku WAM observation of the prompt emission
  3. Trigger 340734: Swift detection of a possible short burst
  4. GRB 090118: Subaru NIR Observation
  5. GRB 090118: KPNO 4m 2nd Epoch Observations
  6. GRB 090118 (BATSS): GRT Optical Observation
  7. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  8. GRB 090118: Swift-XRT observations
  9. GRB090118 Swift/UVOT upper limits
  10. GRB 090118: GROND Upper Limits
  11. GRB 090118: Possible burst detection from Swift-BAT slew data
  12. GRB 090117B : Fermi GBM detection
  13. GRB 090117C - Fermi GRB Detection
  14. GRB 090117 - Fermi GBM Observations
  15. GRB 090117: GROND Upper Limits
  16. GRB090117 Swift/UVOT upper limits
  17. GRB090117: Swift-XRT detection of a possible candidate afterglow
  18. GRB 090117 - SuperAGILE Localization of a long GRB
  19. GRB090102: MAGIC telescope GeV observation
  20. GRB 090112B: Suzaku WAM observation of the prompt emission
  21. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  22. GRB 090113: Swift UVOT upper limits
  23. GRB 090113: GROND Upper Limits
  24. GRB 090113: Swift-XRT refined analysis
  25. GRB 090113: Observations from NOT
  26. GRB 090113: Enhanced Swift-XRT position
  27. GRB 090113: ROTSE-III Optical Limits
  28. GRB 090112B: Fermi GBM Detection
  29. GRB 090113: Swift detection of a burst
  30. GRB 090112: Fermi GBM detection
  31. GRB 090109: Fermi GBM detection
  32. GRB 090108B: Fermi GBM detection
  33. GRB 090111: Swift UVOT Upper Limits
  34. GRB 090108: Fermi GBM Detection
  35. GRB 090111: Swift-XRT refined analysis
  36. GRB 090111: Enhanced Swift-XRT position
  37. GRB 090111: Swift detection of a burst
  38. GRB 090107B: Suzaku WAM observation of the prompt emission
  39. GRB090107B: Fermi GBM Detection
  40. GRB 090107B: Swift XRT afterglow confirmation
  41. GRB 090107B: Swift/UVOT Observations
  42. GRB 090107B: Swift-XRT detection of possible afterglow
  43. Fermi/GBM detection of GRB 081226A
  44. Fermi/GBM detection of GRB 081225
  45. GRB 081231: Fermi GBM Detection
  46. VLA radio upper limit on GRB 090102
  47. GRB 090102: GRT Optical Observation
  48. Swift triggered on the HMXB 1A 1118-61
  49. Konus-Wind observation of GRB 090102
  50. GRB 081229: Fermi GBM detection
  51. GRB 090102: P60 Imaging and P200 Spectroscopy
  52. GRB 090102 Observations from IAC80
  53. GRB 090102: GROND observations of the optical afterglow
  54. GRB 090102: Swift-BAT refined analysis
  55. GRB 090102: Swift XRT refined analysis
  56. GRB 090102: NOT redshift
  57. GRB 090102: Enhanced Swift-XRT position
  58. GRB 090102: REM observations of a bright afterglow
  59. GRB 090102: Swift detection of a burst with an optical counterpart
  60. GRB 090102: TAROT Calern observatory optical observations
  61. GRB 081230: GROND confirmation of the afterglow
  62. GRB081230: Swift-XRT refined analysis
  63. GRB 081230 Swift/UVOT Observations
  64. GRB 081230: Enhanced Swift-XRT position
  65. GRB 081230: Swift detection of a burst
  66. GRB 081226B: Fermi GBM observation
  67. GRB 081226C: Fermi GBM detection
  68. GRB 081228, Swift-BAT refined analysis
  69. VLA radio detection of GRB 081221
  70. GRB 081228: Swift/UVOT Upper Limits
  71. GRB 081228: Swift-XRT Team refined analysis
  72. GRB 081228: detection by GROND
  73. GRB 081228: Enhanced Swift-XRT position
  74. GRB 081228: TAROT Calern observatory optical observations
  75. GRB 081228: Swift detection of a burst
  76. VLA radio observation of GRB 081221
  77. GRB 081226B: Swift XRT and UVOT upper limits
  78. GRB 081224: Suzaku WAM observation of the prompt emission
  79. GRB 081226: Swift-XRT refined analysis
  80. GRB 081226A: Swift UVOT Upper Limits
  81. GRB 081226: GROND afterglow candidate
  82. GRB 081226: ROTSE-III Optical Limits
  83. GRB 081226: Swift detection of a possible short-hard burst
  84. GRB 080810: optical observations
  85. GRB 081211B: optical observations
  86. GRB 081224: Swift-XRT observation
  87. GRB 081222: MITSuME optical observation
  88. GRB 081224: Fermi GBM Detection & LAT Localization
  89. GRB 081223: Fermi GBM detection
  90. GRB 081221: GROND observations
  91. VLA radio upper limit on GRB 081222
  92. GRB 081222: Fermi GBM observation
  93. GRB 081221: Probable host galaxy in Keck imaging
  94. GRB 081204C: Fermi GBM detection
  95. GRB 081222, Swift-BAT refined analysis
  96. GRB081222 optical limit by "Pi of the Sky"
  97. GRB 081222: Swift XRT refined analysis
  98. GRB081221: Fermi GBM observation
  99. IPN triangulation of bright GRB 081215A
  100. GRB 081221: Swift-XRT Refined Analysis

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