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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"

6402 results found.

  1. GRB 141104A: Swift-XRT observations
  2. GRB 141028A: TShAO optical observation
  3. GRB 141102A: Fermi-LAT detection
  4. GRB 141102A: Fermi GBM detection
  5. GRB 141031B: Swift-XRT refined Analysis
  6. GRB 141031A: Swift-XRT refined Analysis
  7. GRB 141031A: Fermi GBM detection
  8. GRB 141028A: SAO RAS Zeiss-1000 photometry
  9. GRB 141029B: Fermi GBM detection
  10. GRB 141028A: Swift-XRT observations
  11. GRB 141028A: Swift/XRT detection of the X-ray afterglow
  12. GRB 141028A: Fermi GBM detection
  13. GRB 141028A: Fermi-LAT detection
  14. GRB 141026A: SAO RAS Zeiss-1000 observations
  15. GRB 141026A: Swift-XRT refined Analysis
  16. GRB141022A: Fermi GBM Detection
  17. GRB141022B: Fermi GBM Detection
  18. GRB 141022A: Swift-XRT refined Analysis
  19. GRB 141020A: Swift-XRT refined Analysis
  20. GRB 141015A: Swift-XRT afterglow confirmation and refined Analysis
  21. GRB 141017A: Swift-XRT refined Analysis
  22. GRB 141011A: Fermi GBM detection
  23. GRB 141004A: Fermi GBM observation
  24. GRB 141004A: Swift-XRT refined Analysis
  25. GRB 141005A: Swift-XRT refined Analysis
  26. GRB 141005A: Fermi GBM Detection
  27. Swift observations of HD 305560
  28. GRB 140928A: Swift-XRT follow-up observations
  29. GRB 140930B: Keck NIR imaging
  30. GRB 140930B: Swift-XRT refined Analysis
  31. GRB 140928A: Fermi GBM detection
  32. GRB 140928A: Swift-XRT observations
  33. GRB 140928A: Fermi-LAT detection
  34. GRB 140927A: Swift-XRT refined Analysis
  35. GRB 140919A: Swift-XRT refined Analysis
  36. GRB 140919A: Fermi GBM observation
  37. GRB 140916A: Swift-XRT refined Analysis
  38. GRB 140909A: Confirmation of the Swift-XRT afterglow
  39. GRB 140909A: Swift-XRT observations
  40. GRB 140907A: Nishi-Harima NIR Observations
  41. GRB 140907A: MITSuME Akeno Optical Observation
  42. GRB 140907A: T100 observations
  43. GRB 140907A: Fermi GBM Detection
  44. GRB 140907A: Swift-XRT refined Analysis
  45. GRB 140907A : Virtual Telescope optical observations
  46. GRB 140906B: Fermi GBM Detection of a Long GRB
  47. GRB 140906A - Fermi GBM Detection
  48. GRB 140901B: Swift XRT observation
  49. GRB 140901B: Fermi GBM detection
  50. GRB 140903A: Swift-XRT refined Analysis
  51. GRB 140901A: Fermi GBM detection
  52. GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
  53. GRB 140829A: Fermi GBM Detection
  54. GRB 140828A: Fermi GBM observation
  55. GRB 140824B: Swift observations
  56. GRB 140824B: Fermi GBM Detection
  57. GRB 140821A: Fermi GBM Detection
  58. GRB 140824A: Swift-XRT refined Analysis
  59. Fermi trigger 430148973: Swift-XRT observation
  60. GRB 140818B: Swift-XRT refined Analysis
  61. GRB 140818B: Fermi GBM detection
  62. GRB 140818A - Fermi GBM Detection
  63. GRB 140818A: Swift-XRT and UVOT potential afterglow detection
  64. GRB 140817A: Swift-XRT refined Analysis
  65. GRB 140817A: Fermi GBM Detection
  66. GRB 140815A: Swift-XRT observations
  67. GRB 140814A: Swift-XRT and UVOT observations
  68. GRB 140814A: Swift-XRT and UVOT observations
  69. GRB 140808A: Confirmation of the Swift-XRT afterglow
  70. GRB140809A: Fermi GBM observation
  71. GRB 140810A: Fermi GBM observation
  72. GRB140810A: Fermi-LAT detection
  73. Swift observations of possible GRB 140809A candidate
  74. GRB 140808A: Swift/UVOT Upper Limits
  75. GRB 140808A: Swift-XRT observations
  76. GRB140801A: Swift/XRT further observations
  77. GRB 140801A: Swift/UVOT Upper Limits
  78. GRB 140801A: Swift-XRT observations
  79. GRB 140801A: Fermi GBM observation
  80. GRB 140730A: Swift-XRT refined Analysis
  81. GRB 140729A: Swift-XRT and UVOT observations
  82. GRB 140729A: Fermi-GBM detection
  83. GRB 140729A: Fermi-LAT detection
  84. GRB 140723A: Swift-XRT and UVOT observations
  85. GRB 140723A: Fermi GBM detection
  86. GRB 140723A: Fermi-LAT detection
  87. GRB 140719B: Swift XRT observation
  88. GRB 140721A: Fermi GBM detection
  89. GRB 140716A: Confirmation of the Swift-XRT afterglow
  90. GRB 140719A: Swift-XRT refined Analysis
  91. GRB 140716A: Swift-XRT detection of an afterglow candidate
  92. GRB 140716A: A Fermi GBM Detection
  93. Swift observations of a flare from UX Ari
  94. GRB 140714A: Fermi GBM detection
  95. GRB 140713A: Swift-XRT refined Analysis
  96. GRB 140713A: T100 observations
  97. GRB 140710B: Fermi GBM detection
  98. GRB 140710A: Swift-XRT refined Analysis
  99. GRB 140709B: Swift-XRT refined Analysis
  100. GRB 140709A: Fermi GBM detection

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