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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"

19592 results found.

  1. GRB 090812: WIRO NIR upper limit
  2. GRB 090812: Faulkes Telescope South Continued Optical Monitoring
  3. GRB 090812: RAPTOR detections during the burst
  4. GRB 090812: Swift XRT refined analysis
  5. GRB 090812, RIMOTS optical upper limits
  6. GRB 090812 Swift-BAT Refined Analysis
  7. GRB090812: Swift/UVOT observations
  8. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  9. GRB 090812: Enhanced Swift-XRT position
  10. GRB 090812: Liverpool Telescope afterglow confirmation
  11. GRB 090812: Swift detection of a burst with an optical counterpart
  12. GRB 090809: Swift-XRT refined analysis
  13. GRB090809: Swift/UVOT observations
  14. GRB 090809: Enhanced Swift-XRT position
  15. GRB 090809: Swift-BAT refined analysis
  16. GRB 090809: Swift detection of a burst with a possible optical counterpart
  17. GRB 090807: Liverpool Telescope observations
  18. GRB 090807: Swift/UVOT Upper Limits
  19. GRB 090807: Swift-XRT refined analysis
  20. GRB 090807, Swift-BAT refined analysis
  21. GRB 090807: Enhanced Swift-XRT position
  22. GRB 090807, RIMOTS optical upper limits
  23. GRB 090807: Swift detection of a burst
  24. GRB 090726: optical observation
  25. Swift-BAT trigger 358760 is most likely not a GRB
  26. Swift trigger 358760 is probably a noise event
  27. GRB 090709A : Quick look analysis of the Suzaku observation
  28. GRB 090728: Swift-BAT refined analysis
  29. GRB 090727: GRT Optical Observation
  30. GRB 090728: Swift XRT refined analysis
  31. GRB 090726: GRT Optical Observation
  32. GRB 090727: Swift/UVOT Upper Limits
  33. GRB 090728: Swift/UVOT Upper Limits
  34. GRB 090728: Enhanced Swift-XRT position
  35. GRB 090728, RIMOTS optical upper limits
  36. GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
  37. GRB 090728: Swift detection of a burst
  38. GRB 090727: Swift-BAT refined analysis
  39. GRB 090727: Swift-XRT refined analysis
  40. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  41. GRB 090727: Enhanced Swift-XRT position
  42. GRB 090727: Liverpool Telescope possible OT candidate
  43. GRB 090727: Swift detection of a burst
  44. GRB090726: Swift/UVOT observations
  45. GRB 090726, Swift-BAT refined analysis
  46. GRB 090726: Afterglow candidate photometryfrom Crni Vrh
  47. GRB 090726: D50 optical observations
  48. GRB 090726: Swift-XRT Team refined analysis
  49. GRB 090726: Enhanced Swift-XRT position
  50. GRB 090726: Swift/UVOT Finding Chart Observation
  51. GRB 090726: Swift-XRT position of probable counterpart
  52. GRB 090726: Swift detection of a burst
  53. Swift Trigger 358354 is not a GRB
  54. GRB 090720: Gemini-North Imaging and Optical Afterglow
  55. Swift XRT and UVOT refned analysis of GRB 090720
  56. GRB 090709A: Swift XRT Timing Analysis
  57. GRB 090715B: VLA radio detection
  58. GRB 090720 Source found in ground processing of Swift-BAT data
  59. GRB 090715A: Suzaku WAM observation of the prompt emission
  60. GRB 090709A - CARMA mm Observations
  61. Konus-Wind observations of short/hard GRB 090715A
  62. GRB 090715B: MASTER optical limit
  63. GRB 090715A: Swift-BAT refined analysis
  64. GRB 090715B: Swift/UVOT followup observations
  65. GRB 090715B: break in the optical afterglow decay
  66. GRB 090715B: Enhanced Swift-XRT position
  67. GRB 090715B: Swift XRT Refined Analysis
  68. GRB 090715B: Swift-BAT refined analysis
  69. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  70. Swift problem fixed
  71. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  72. GRB 090715A: ROTSE-III Optical Limits
  73. GRB 090715: Swift detection of a short hard burst
  74. Swift satellite anomaly
  75. GRB 090712: Fermi GBM observation
  76. GRB 090712: Swift-BAT refined analysis
  77. GRB 090712: Swift detection of a burst
  78. GRB 090621B: MTM-500 optical observations
  79. GRB 090709A: deep optical observation with the 10.4m GTC
  80. GRB 090709A: Suzaku WAM observation of the prompt emission
  81. GRB 090709A: Swift UVOT upper limits
  82. GRB 090709B: Fermi GBM detection
  83. GRB 090709A: confirmation of the periodicity in the SPI-ACS data
  84. GRB 090709A: evidence for a very red afterglow at low z
  85. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  86. GRB 090709A: Swift XRT Refined Analysis
  87. GRB 090709B, Swift-BAT refined analysis
  88. GRB 090709A: Swift-BAT refined analysis
  89. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  90. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  91. GRB 090709A, RIMOTS optical upper limits
  92. GRB 090709A: Enhanced Swift-XRT position
  93. GRB 090709B: Swift detection of a burst
  94. GRB 090708 : Fermi GBM detection
  95. GRB 090709: Faulkes Telescope North Upper Limits
  96. GRB 090709: PAIRITEL NIR Upper Limits
  97. GRB 090709: ROTSE-III Optical Limits
  98. GRB 090709: Swift detection of a bright burst
  99. GRB 090708: Early RAPTOR Optical Limits
  100. GRB 090708, Swift-BAT refined analysis

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