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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"

23415 results found.

  1. GRB090904B: REM observations
  2. GRB 090904B: Swift detection of a burst
  3. GRB 090904A: ROTSE-III Optical Limits
  4. GRB 090904: Swift detection of a burst
  5. GRB 090902B: Swift/UVOT refined analysis
  6. GRB 090902B: GROND NIR Afterglow Observations
  7. GRB 090902B: Enhanced Swift-XRT position
  8. GRB090902B: Swift/UVOT observations
  9. GRB 090902B: Swift/XRT Afterglow Candidate
  10. GRB 090902B: Fermi LAT detection
  11. GRB 090902B: Fermi GBM detection of a bright burst
  12. GRB 090902: Fermi GBM detection
  13. GRB 090831A: IPN Triangulation
  14. GRB 090831C: GROND upper limits
  15. Swift Trigger 361477, called GRB090831B, is probably not real.
  16. GRB090831C: Swift/UVOT upper limits
  17. GRB 090831B: MITSuME optical upper limits
  18. GRB 090829B: Fermi GBM Detection
  19. GRB 090831C: Enhanced Swift-XRT position
  20. GRB 090831C: Swift detection of a burst
  21. GRB 090831B, RIMOTS optical upper limits
  22. GRB 090831: MAXI GSC detection
  23. GRB 090831B: Swift detection of a possible burst
  24. GRB 090831: Fermi GBM detection
  25. GRB090829: Fermi GBM Detection
  26. GRB 090827: Swift XRT and UVOT observations
  27. GRB 090827 Burst discovered in BAT ground analysis
  28. GRB 090826: Fermi GBM detection
  29. GRB 090828: Fermi GBM detection
  30. GRB 090817 - TLS Observations
  31. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  32. GRB 090823 Long burst with IPN triangulation and BAT position
  33. GRB 090820B: Fermi GBM detection
  34. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  35. GRB 090820: MASTER-Net optical polarization observations
  36. GRB 090820: Fermi GBM Detection of a bright burst.
  37. GRB 090817: optical upper limit
  38. GRB 090817: Confirmation of the X-ray afterglow
  39. GRB 090815C: Swift refined analysis
  40. GRB 090817: Swift/UVOT Upper Limits
  41. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  42. GRB 090817: Swift-XRT observations
  43. GRB 090814A: optical observations
  44. VLA radio non-detection of GRB 090812
  45. GRB 090815B: Fermi GBM detection
  46. GRB 090815: Fermi GBM detection
  47. GRB 090813: CrAO optical obsevations
  48. GRB090814A: NOT optical follow-ups
  49. GRB 090814B: I-band observations from 1.23m CAHA telescope
  50. GRB 090814B: Swift/UVOT Upper Limits
  51. GRB 090814C: Fermi GBM detection
  52. GRB 090814B: Swift-XRT detection of a possible afterglow.
  53. GRB 090814A: Swift/UVOT Observations
  54. GRB 090814A: Swift-XRT Team Refined Analysis
  55. GRB 090814A, RIMOTS optical upper limits
  56. GRB 090814A: Swift-BAT refined analysis
  57. GRB090814A: VLT spectroscopy
  58. GRB 090814: Enhanced Swift-XRT position
  59. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  60. GRB 090814: Swift detection of a burst
  61. GRB090813: Swift/UVOT upper limits
  62. GRB 090813: Enhanced Swift-XRT position
  63. GRB 090813: P60 Optical Afterglow Confirmation
  64. GRB 090813: Swift detection of a burst
  65. GRB 090812: WIRO NIR upper limit
  66. GRB 090812: Faulkes Telescope South Continued Optical Monitoring
  67. GRB 090812: RAPTOR detections during the burst
  68. GRB 090812, RIMOTS optical upper limits
  69. GRB 090812 Swift-BAT Refined Analysis
  70. GRB090812: Swift/UVOT observations
  71. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  72. GRB 090812: Enhanced Swift-XRT position
  73. GRB 090812: P60 Confirmation of Optical Afterglow
  74. GRB 090812: Swift detection of a burst with an optical counterpart
  75. GRB 090807B: Fermi GBM detection
  76. GRB 090809: Further NOT optical observations
  77. VLA radio upper limit on GRB 090809
  78. GRB 090809: WHT observations
  79. GRB 090809B: Fermi GBM detection
  80. GRB090809: Swift/UVOT observations
  81. GRB 090809: Enhanced Swift-XRT position
  82. GRB 090809: Swift-BAT refined analysis
  83. GRB 090809: afterglow confirmation at the NOT
  84. GRB 090809: Swift detection of a burst with a possible optical counterpart
  85. GRB 090807: MITSuME optical upper limit
  86. GRB 090807: Swift/UVOT Upper Limits
  87. GRB 090807: Enhanced Swift-XRT position
  88. GRB 090807, RIMOTS optical upper limits
  89. GRB 090807: Swift detection of a burst
  90. GRB 090802B: Fermi GBM detection
  91. IPN Triangulation and Konus-Wind observaions of GRB090727B
  92. GRB 090802: Fermi GBM detection
  93. GRB 090726: optical observation
  94. Swift trigger 358760 is probably a noise event
  95. GRB 090727: GRT Optical Observation
  96. GRB 090726: GRT Optical Observation
  97. GRB 090727: Swift/UVOT Upper Limits
  98. GRB 090728: Swift/UVOT Upper Limits
  99. GRB 090728: Enhanced Swift-XRT position
  100. GRB 090728, RIMOTS optical upper limits

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