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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"

6200 results found.

  1. GRB 121108A: Swift-XRT refined Analysis
  2. GRB 121031A: Fermi GBM detection
  3. GRB 121031A: Swift-XRT refined Analysis
  4. GRB 121102A: Swift-XRT refined Analysis
  5. GRB 121029A: Fermi GBM detection
  6. GRB 121027A: Swift-XRT refined Analysis
  7. GRB 121028A: Swift-XRT refined Analysis
  8. GRB 121025A: Swift-XRT observation
  9. GRB 121024A: Swift/UVOT Observations
  10. GRB 121024A: PAIRITEL NIR Detection
  11. GRB 121024A: Swift-XRT refined Analysis
  12. GRB 121017A: Swift-XRT refined Analysis
  13. GRB 121012A: Fermi GBM detection
  14. GRB 121011A: optical observations
  15. GRB 121011A: Fermi-LAT detection of a burst
  16. GRB 121011A: Swift-XRT refined Analysis
  17. GRB 120804A: Late-time Chandra observation
  18. GRB 121001A: Swift-XRT refined Analysis
  19. GRB 120927A: Swift-XRT refined Analysis
  20. Further Swift-XRT observations of the GRB 120919A field.
  21. GRB 120921A: Fermi GBM detection of its 1000th GRB
  22. GRB 120923A: Swift-XRT refined Analysis
  23. GRB 120922A: Fermi GBM detection
  24. GRB 120922A: Swift-XRT refined Analysis
  25. GRB 120919A: Swift/UVOT Upper Limits
  26. GRB 120919A: Swift-XRT observations
  27. Konus-Wind observation of GRB 120919B
  28. GRB 120919A: Fermi GBM detection
  29. GRB 120916A: Fermi GBM Observation
  30. GRB 120916A: Fermi-LAT detection of a burst
  31. Corrections to the Fermi-LAT upper limits for GRB 120807A, 120908A, 120909A, and 120911A
  32. GRB 120913B: Fermi GBM observation
  33. GRB 120913A: Fermi GBM observation
  34. GRB 120911B: Fermi GBM observation
  35. GRB 120911B: Fermi-LAT detection of a burst
  36. GRB 120911A: Fermi GBM observation
  37. GRB 120911A: Swift-XRT refined Analysis
  38. GRB 120908A: Fermi GBM detection
  39. GRB 120908A: Swift Observations
  40. GRB 120909A: Fermi GBM observation
  41. GRB 120909A: Swift-XRT refined Analysis
  42. GRB 120907A: Swift-XRT refined Analysis
  43. GRB 120907A: Fermi GBM detection
  44. XMM observations of the short GRB120804A
  45. GRB 120830A: Further Swift Observations
  46. GRB 120830A: Swift-XRT and UVOT observations
  47. GRB 120830A: Fermi GBM observation
  48. GRB 120830A: early MASTER optical limit
  49. GRB 120830A: Fermi-LAT detection of a short burst
  50. Fermi trigger 368003226 : MASTER optical observations
  51. GRB 120821A: Swift/XRT observations
  52. GRB 120819A: GROND afterglow confirmation
  53. GRB 120819A: Swift-XRT refined Analysis
  54. GRB 120817B: Swift-XRT observations
  55. GRB 120817A: Swift-XRT refined Analysis
  56. GRB 120817B: Fermi GBM detection
  57. GRB 120816A: Swift-XRT refined Analysis
  58. GRB 120815A: Swift-XRT refined Analysis
  59. GRB 120811B: Fermi GBM observation
  60. GCN for GRB 120811C
  61. GRB 120811A: Swift/XRT-UVOT Obseravations
  62. GRB120804A: Chandra observations and afterglow detection
  63. GRB 120805A: Enhanced Swift-XRT position
  64. GRB 120811C: Swift-XRT refined Analysis
  65. GRB 120811C: RTT150 optical observations
  66. GRB 120803A: Confirmation of the X-ray afterglow
  67. GRB 120807A: Swift-XRT refined Analysis
  68. Fermi/GBM detection of an SGR-like burst
  69. Swift trigger 530214: uncertain if real or not
  70. GRB 120728A: Fermi GBM observation
  71. GRB 120802A: Swift/UVOT Upper Limits
  72. GRB 120805A: Swift-XRT refined Analysis
  73. GRB 120803B: Swift-XRT refined Analysis
  74. GRB 120804A: Swift-XRT refined Analysis
  75. GRB 120803A: Swift-XRT Observations
  76. GRB 120803A: Swift detection of a possible burst
  77. GRB 120802A: Swift-XRT refined Analysis
  78. GRB 120729A: Fermi GBM observation
  79. GRB 120728B: Fermi GBM detection
  80. Virtual Telescope observations of GRB 120729A
  81. T100 observations of GRB 120729A
  82. GRB 120729A: Swift-XRT refined Analysis
  83. GRB 120728A: Swift-XRT refined Analysis
  84. GRB 120728A: GROND observations
  85. GRB 120727A/Galactic source: Fermi-LAT detection of a transient source
  86. GRB 120724A: Swift-XRT refined Analysis
  87. GRB 120709A: Swift re-observation of the field of the X-ray counterpart candidate.
  88. GRB 120722A: Swift-XRT refined Analysis
  89. GRB 120716A: Fermi GBM observation
  90. GRB 120716A: Swift-XRT detection
  91. GRB 120714B: Swift-XRT refined Analysis
  92. GRB 120714A: GROND upper limits
  93. GRB 120714B: GROND confirmation of fading afterglow
  94. GRB 120714A: Swift-XRT refined Analysis
  95. GRB 120712A: Fermi GBM observation
  96. GRB 120712A: Swift-XRT refined Analysis
  97. GRB 120711B: Swift-XRT refined Analysis
  98. GRB 120709A: Swift/UVOT Observations
  99. GRB 120711A: Fermi LAT detection
  100. GRB 120711A: Swift-XRT observations

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