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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"

27032 results found.

  1. GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
  2. GRB 090820: detection of a strong burst by RT-2 on board CORONAS PHOTON
  3. GRB 090820B: Fermi GBM detection
  4. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  5. GRB 090820: Fermi GBM Detection of a bright burst.
  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 090813: Suzaku WAM observation of the prompt emission
  11. GRB 090812: Suzaku WAM observation of the prompt emission
  12. GRB 090815B: Fermi GBM detection
  13. GRB 090815: Fermi GBM detection
  14. Fermi Gamma-ray Burst Monitor trigger 271934815 is not a GRB
  15. GRB 090814C: Fermi GBM detection
  16. GRB 090814A: Swift/UVOT Observations
  17. GRB 090814A: Swift-XRT Team Refined Analysis
  18. GRB 090814A, RIMOTS optical upper limits
  19. GRB 090814A: Swift-BAT refined analysis
  20. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  21. GRB 090814: Swift detection of a burst
  22. GRB 090813: Fermi GBM observation
  23. Fermi Gamma-ray Burst Monitor trigger 271446248 is not a GRB
  24. GRB 090813: Swift-XRT refined analysis
  25. Fermi Gamma-ray Burst Monitor trigger 271833016 is not a GRB
  26. GRB 090813, Swift-BAT refined analysis
  27. Konus-Wind observations of GRB090813
  28. GRB090813: Swift/UVOT upper limits
  29. GRB 090813: Liverpool Telescope afterglow confirmation
  30. GRB 090813: optical candidate from 1.23m CAHA telescope
  31. GRB 090813: Swift detection of a burst
  32. GRB 090812: WIRO NIR upper limit
  33. GRB 090812: Faulkes Telescope South Continued Optical Monitoring
  34. GRB 090812: RAPTOR detections during the burst
  35. GRB 090812: Swift XRT refined analysis
  36. GRB 090812, RIMOTS optical upper limits
  37. GRB 090812 Swift-BAT Refined Analysis
  38. GRB090812: Swift/UVOT observations
  39. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  40. GRB 090812: Liverpool Telescope afterglow confirmation
  41. GRB 090812: Swift detection of a burst with an optical counterpart
  42. GRB 090807B: Fermi GBM detection
  43. GRB 090809B: Fermi GBM detection
  44. GRB 090809: Swift-XRT refined analysis
  45. GRB090809: Swift/UVOT observations
  46. GRB 090809: Swift-BAT refined analysis
  47. GRB 090809: Swift detection of a burst with a possible optical counterpart
  48. GRB 090807: Liverpool Telescope observations
  49. GRB 090807: Swift/UVOT Upper Limits
  50. GRB 090807: Swift-XRT refined analysis
  51. GRB 090807, Swift-BAT refined analysis
  52. GRB 090807, RIMOTS optical upper limits
  53. GRB 090807: Swift detection of a burst
  54. Fermi Gamma-ray Burst Monitor trigger 271275771 is not a GRB
  55. GRB 090802B: Fermi GBM detection
  56. GRB 090802: Fermi GBM detection
  57. Swift-BAT trigger 358760 is most likely not a GRB
  58. Swift trigger 358760 is probably a noise event
  59. GRB 090717A: Suzaku WAM observation of the prompt emission
  60. GRB 090709A : Quick look analysis of the Suzaku observation
  61. GRB 090728: Swift-BAT refined analysis
  62. GRB 090727: GRT Optical Observation
  63. GRB 090728: Swift XRT refined analysis
  64. GRB 090727: optical observations
  65. GRB 090726: GRT Optical Observation
  66. GRB 090727: Swift/UVOT Upper Limits
  67. GRB 090728: Swift/UVOT Upper Limits
  68. GRB 090728, RIMOTS optical upper limits
  69. GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
  70. GRB 090728: Swift detection of a burst
  71. GRB 090727: Swift-BAT refined analysis
  72. GRB 090727: Swift-XRT refined analysis
  73. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  74. GRB 090727: Liverpool Telescope possible OT candidate
  75. GRB 090727: Swift detection of a burst
  76. GRB090726: Swift/UVOT observations
  77. GRB 090726, Swift-BAT refined analysis
  78. GRB 090726: D50 optical observations
  79. GRB 090711: Fermi GBM detection
  80. GRB090726: 6-meter telescope redshift
  81. GRB 090726: Swift-XRT Team refined analysis
  82. GRB 090726: optical transient candidate
  83. GRB 090726: Swift/UVOT Finding Chart Observation
  84. GRB 090726: Swift-XRT position of probable counterpart
  85. GRB 090726: Swift detection of a burst
  86. Swift Trigger 358354 is not a GRB
  87. Konus-Wind and Konus-RF observations of GRB 090719
  88. Konus-RF and Konus-Wind observations of GRB 090718B
  89. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  90. Konus-Wind observations of bright hard GRB 090720B
  91. IPN Triangulation of bright GRB 090720B
  92. GRB 090720: Gemini-North Imaging and Optical Afterglow
  93. GRB 090720B: Fermi GBM detection
  94. GRB 090709A: Swift XRT Timing Analysis
  95. GRB 090720 Source found in ground processing of Swift-BAT data
  96. GRB 090717B: Fermi GBM detection
  97. GRB 090717: Fermi GBM detection
  98. GRB 090719: Fermi GBM detection
  99. GRB 090718B: Fermi GBM detection
  100. GRB 090718: Fermi GBM detection

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