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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"

28040 results found.

  1. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  2. GRB 090820: MASTER-Net optical polarization observations
  3. GRB 090820: Fermi GBM Detection of a bright burst.
  4. GRB 090817: optical upper limit
  5. GRB 090817: Confirmation of the X-ray afterglow
  6. GRB 090815C: Swift refined analysis
  7. GRB 090817: Fermi GBM observation
  8. GRB 090817: Swift/UVOT Upper Limits
  9. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  10. GRB 090817: Swift-XRT observations
  11. GRB 090814A: optical observations
  12. GRB 090813: Suzaku WAM observation of the prompt emission
  13. GRB 090812: Suzaku WAM observation of the prompt emission
  14. VLA radio non-detection of GRB 090812
  15. GRB 090815B: Fermi GBM detection
  16. GRB 090815: Fermi GBM detection
  17. GRB 090813: CrAO optical obsevations
  18. GRB090814A: NOT optical follow-ups
  19. GRB 090814B: Swift/UVOT Upper Limits
  20. GRB 090814B: Liverpool Telescope Observations
  21. GRB 090814C: Fermi GBM detection
  22. GRB 090814B: Swift-XRT detection of a possible afterglow.
  23. GRB 090814A: Swift/UVOT Observations
  24. GRB 090814A: Swift-XRT Team Refined Analysis
  25. GRB 090814A, RIMOTS optical upper limits
  26. GRB 090814A: Swift-BAT refined analysis
  27. GRB090814A: VLT spectroscopy
  28. GRB 090814: Enhanced Swift-XRT position
  29. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  30. GRB 090814: Swift detection of a burst
  31. GRB 090813: Swift-XRT refined analysis
  32. GRB 090813, Swift-BAT refined analysis
  33. Konus-Wind observations of GRB090813
  34. GRB090813: Swift/UVOT upper limits
  35. GRB 090813: Enhanced Swift-XRT position
  36. GRB 090813: Liverpool Telescope afterglow confirmation
  37. GRB 090813: P60 Optical Afterglow Confirmation
  38. GRB 090813: Swift detection of a burst
  39. GRB 090812: Faulkes Telescope South Continued Optical Monitoring
  40. GRB 090812: RAPTOR detections during the burst
  41. GRB 090812: Swift XRT refined analysis
  42. GRB 090812, RIMOTS optical upper limits
  43. GRB 090812 Swift-BAT Refined Analysis
  44. GRB090812: Swift/UVOT observations
  45. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  46. GRB 090812: Enhanced Swift-XRT position
  47. GRB 090812: P60 Confirmation of Optical Afterglow
  48. GRB 090812: Swift detection of a burst with an optical counterpart
  49. GRB 090807B: Fermi GBM detection
  50. GRB 090809: Further NOT optical observations
  51. VLA radio upper limit on GRB 090809
  52. GRB 090621B: MAGIC telescope GeV observation
  53. GRB 090621A: MAGIC telescope GeV observation
  54. GRB 090809: WHT observations
  55. GRB 090809B: Fermi GBM detection
  56. GRB 090809: Swift-XRT refined analysis
  57. GRB090809: Swift/UVOT observations
  58. GRB 090809: Enhanced Swift-XRT position
  59. GRB 090809: Swift-BAT refined analysis
  60. GRB 090809: afterglow confirmation at the NOT
  61. GRB 090809: Swift detection of a burst with a possible optical counterpart
  62. GRB 090807: Liverpool Telescope observations
  63. GRB 090807: MITSuME optical upper limit
  64. GRB 090807: Swift/UVOT Upper Limits
  65. GRB 090807: Swift-XRT refined analysis
  66. GRB 090807, Swift-BAT refined analysis
  67. GRB 090807: Enhanced Swift-XRT position
  68. GRB 090807, RIMOTS optical upper limits
  69. GRB 090807: Swift detection of a burst
  70. GRB 090802B: Fermi GBM detection
  71. GRB 090802: Fermi GBM detection
  72. GRB 090726: optical observation
  73. Swift trigger 358760 is probably a noise event
  74. GRB 090717A: Suzaku WAM observation of the prompt emission
  75. GRB 090709A : Quick look analysis of the Suzaku observation
  76. GRB 090728: Swift-BAT refined analysis
  77. GRB 090727: GRT Optical Observation
  78. GRB 090728: Swift XRT refined analysis
  79. GRB 090726: GRT Optical Observation
  80. GRB 090727: Swift/UVOT Upper Limits
  81. GRB 090728: Swift/UVOT Upper Limits
  82. GRB 090728: Enhanced Swift-XRT position
  83. GRB 090728, RIMOTS optical upper limits
  84. GRB 090728: Swift detection of a burst
  85. GRB 090727: Swift-BAT refined analysis
  86. GRB 090727: Swift-XRT refined analysis
  87. GRB 090727: Enhanced Swift-XRT position
  88. GRB 090715B: Late-time Lick 3m observations
  89. GRB 090727: Swift detection of a burst
  90. GRB090726: Swift/UVOT observations
  91. GRB 090726, Swift-BAT refined analysis
  92. GRB 090726: Afterglow candidate photometryfrom Crni Vrh
  93. GRB 090726: D50 optical observations
  94. GRB 090711: Fermi GBM detection
  95. GRB 090726: Swift-XRT Team refined analysis
  96. GRB 090726: Enhanced Swift-XRT position
  97. GRB 090726: optical transient candidate
  98. Konus-RF and Konus-Wind observations of GRB 090718B
  99. GRB 090720B: Fermi GBM detection
  100. Swift XRT and UVOT refned analysis of GRB 090720

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