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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"

28089 results found.

  1. GRB 090621B: MAGIC telescope GeV observation
  2. GRB 090621A: MAGIC telescope GeV observation
  3. GRB 090809: WHT observations
  4. GRB 090809B: Fermi GBM detection
  5. GRB 090809: Swift-XRT refined analysis
  6. GRB090809: Swift/UVOT observations
  7. GRB 090809: Enhanced Swift-XRT position
  8. GRB 090809: Swift-BAT refined analysis
  9. GRB 090809: afterglow confirmation at the NOT
  10. GRB 090809: Swift detection of a burst with a possible optical counterpart
  11. GRB 090807: Liverpool Telescope observations
  12. GRB 090807: MITSuME optical upper limit
  13. GRB 090807: Swift/UVOT Upper Limits
  14. GRB 090807: Swift-XRT refined analysis
  15. GRB 090807, Swift-BAT refined analysis
  16. GRB 090807: Enhanced Swift-XRT position
  17. GRB 090807, RIMOTS optical upper limits
  18. GRB 090807: Swift detection of a burst
  19. GRB 090802B: Fermi GBM detection
  20. GRB 090802: Fermi GBM detection
  21. GRB 090726: optical observation
  22. Swift trigger 358760 is probably a noise event
  23. GRB 090717A: Suzaku WAM observation of the prompt emission
  24. GRB 090709A : Quick look analysis of the Suzaku observation
  25. GRB 090728: Swift-BAT refined analysis
  26. GRB 090727: GRT Optical Observation
  27. GRB 090728: Swift XRT refined analysis
  28. GRB 090726: GRT Optical Observation
  29. GRB 090727: Swift/UVOT Upper Limits
  30. GRB 090728: Swift/UVOT Upper Limits
  31. GRB 090728: Enhanced Swift-XRT position
  32. GRB 090728, RIMOTS optical upper limits
  33. GRB 090728: Swift detection of a burst
  34. GRB 090727: Swift-BAT refined analysis
  35. GRB 090727: Swift-XRT refined analysis
  36. GRB 090727: Enhanced Swift-XRT position
  37. GRB 090715B: Late-time Lick 3m observations
  38. GRB 090727: Swift detection of a burst
  39. GRB090726: Swift/UVOT observations
  40. GRB 090726, Swift-BAT refined analysis
  41. GRB 090726: Afterglow candidate photometryfrom Crni Vrh
  42. GRB 090726: D50 optical observations
  43. GRB 090711: Fermi GBM detection
  44. GRB 090726: Swift-XRT Team refined analysis
  45. GRB 090726: Enhanced Swift-XRT position
  46. GRB 090726: optical transient candidate
  47. Konus-RF and Konus-Wind observations of GRB 090718B
  48. GRB 090720B: Fermi GBM detection
  49. Swift XRT and UVOT refned analysis of GRB 090720
  50. GRB 090709A: Swift XRT Timing Analysis
  51. GRB 090715B: VLA radio detection
  52. GRB 090720 Source found in ground processing of Swift-BAT data
  53. GRB 090717B: Fermi GBM detection
  54. GRB 090717: Fermi GBM detection
  55. GRB 090719: Fermi GBM detection
  56. GRB 090718B: Fermi GBM detection
  57. GRB 090718: Fermi GBM detection
  58. GRB 090720: Fermi GBM detection
  59. GRB 090715B: further NOT optical observations
  60. GRB 090715A: Suzaku WAM observation of the prompt emission
  61. GRB 090709A - CARMA mm Observations
  62. GRB 090715B: Lick observations
  63. GRB 090715A: VLA observations
  64. GRB 090715A: Swift-BAT refined analysis
  65. GRB 090715B: Swift/UVOT followup observations
  66. GRB 090715B: Enhanced Swift-XRT position
  67. GRB 090715B: Observation of the optical afterglow
  68. GRB 090715B: Swift XRT Refined Analysis
  69. GRB 090715B: Swift-BAT refined analysis
  70. GRB 090715B: NOT optical observations
  71. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  72. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  73. GRB 090713: Fermi GBM detection
  74. GRB 090712: Swift-BAT refined analysis
  75. VLA radio observations of GRB 090709A
  76. GRB 090621B: MTM-500 optical observations
  77. GRB 090709A: deep optical observation with the 10.4m GTC
  78. GRB 090709A: Suzaku WAM observation of the prompt emission
  79. GRB 090709A: Swift UVOT upper limits
  80. GRB 090709A: WHT LIRIS observations
  81. GRB 090709B: Fermi GBM detection
  82. GRB 090709A: evidence for a very red afterglow at low z
  83. GRB 090709A: P60 Observations
  84. GRB 090709A: NOT optical observations
  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 090709A: Subaru NIR observation
  94. GRB 090709 : planned Suzaku-ToO observation
  95. GRB 090708 : Fermi GBM detection
  96. GRB 090709: Faulkes Telescope North Upper Limits
  97. GRB 090626: Suzaku WAM observation of the prompt emission
  98. GRB 090709: PAIRITEL NIR Upper Limits
  99. GRB 090704: Fermi GBM observation
  100. GRB 090709: Swift detection of a bright burst

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