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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"

27039 results found.

  1. GRB 120907A: Swift-BAT refined analysis
  2. GRB 120907A: NOT optical observations
  3. GRB 120907A: ROTSE-III Optical Limits
  4. GRB 120907A: Swift detection of a burst with optical counterpart
  5. GRB 120830A: Further Swift Observations
  6. GRB 120830A: Swift-XRT and UVOT observations
  7. GRB 120830A: Fermi GBM observation
  8. IPN Triangulation of short GRB 120830A
  9. GRB 120830A: Fermi-LAT detection of a short burst
  10. Fermi trigger 368003226 : MASTER optical observations
  11. GRB 120819A: Swift/UVOT Upper Limits
  12. GRB 120817A: Swift/UVOT Upper Limits
  13. GRB 120821A: Swift/XRT observations
  14. GRB 120821A: Swift/UVOT Upper Limits
  15. GRB 120821A: GROND upper limits
  16. GRB 120817A: RAPTOR Limits During Gamma-Ray Emitting Interval
  17. GRB 120817B: BAT location in ground analysis and refined analysis
  18. GRB 120819A: Bassano Bresciano Observatory optical observations
  19. GRB 120819A: Swift-BAT refined analysis
  20. GRB 120819A: GROND afterglow confirmation
  21. GRB 120819A: Swift-XRT refined Analysis
  22. GRB 120819A: Swift detection of a burst
  23. GRB 120817B: Swift-XRT observations
  24. GRB 120816A: Swift/UVOT Detection of the Optical Afterglow
  25. GRB 120817A: Swift-XRT refined Analysis
  26. GRB 120817B: Fermi GBM detection
  27. IPN Triangulation of GRB 120817B (short/very intense)
  28. GRB 120817A: Swift-BAT refined analysis
  29. GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
  30. GRB 120816A: Bassano Bresciano Observatory optical observations
  31. GRB 120817A: FTN and FTS observations
  32. GRB 120816A: Swift-XRT refined Analysis
  33. GRB 120817A: Swift-XRT observations
  34. GRB 120817A: Swift detection of a burst
  35. GRB 120816A: Swift-BAT refined analysis
  36. GRB 120816A: TAROT Calern observatory optical observations
  37. GRB 120816A: ROTSE-III Optical Limits
  38. GRB 120816A: Swift detection of a burst
  39. GRB 120815A: Swift-XRT refined Analysis
  40. GRB 120815A: Swift-BAT refined analysis
  41. GRB 120805A: Liverpool Telescope optical candidate detection
  42. GRB 120815A: GROND afterglow candidate
  43. GRB 120815A: Swift-XRT observations
  44. GRB 120815A: TAROT La Silla observatory optical observations
  45. GRB 120815A: Swift detection of a burst
  46. GRB 120811B: Fermi GBM observation
  47. GCN for GRB 120811C
  48. GRB 120811A: Swift/XRT-UVOT Obseravations
  49. GRB120804A: Chandra observations and afterglow detection
  50. GRB 120811C: Swift-BAT refined analysis
  51. GRB 120811A: Swift-BAT refined analysis
  52. GRB 120811C: NOT redshift
  53. GRB 120811C: Bassano Bresciano Observatory optical observations
  54. GRB 120811C: Swift-XRT refined Analysis
  55. GRB 120811C: Swift/UVOT Detection
  56. GRB 120811C: TAROT Calern observatory optical observations
  57. GRB 120811C: Swift detection of a burst with an optical counterpart
  58. IPN Triangulation of short hard GRB 120811B
  59. Trigger 530588: Swift detection of XMM J174457-2850.3
  60. Swift Trigger 530581: GRB 120811A or a galactic transient
  61. GRB 120807A: Swift/UVOT Upper Limits
  62. GRB 120803A: Confirmation of the X-ray afterglow
  63. GRB 120804A: Konus-Wind and Swift/BAT joint spectral analysis
  64. GRB 120714B: GROND/FORS2 detection of a supernova
  65. Swift Trigger 530441 is a false trigger
  66. GRB 120807A: Swift-XRT refined Analysis
  67. GRB 120807A: Fermi/LAT upper limit
  68. GRB 120807A: RAPTOR Limits During Gamma-Ray Emitting Interval
  69. GRB 120804A: Gemini-North detection of an optical afterglow and putative host galaxy
  70. GRB 120807A: TAROT La Silla observatory optical observations
  71. GRB 120807A: Swift-BAT refined analysis
  72. GRB 120807A: Swift detection of a burst
  73. Fermi/GBM detection of an SGR-like burst
  74. Swift-BAT trigger 530214 is noise
  75. GRB 120805A: Swift/UVOT Upper Limits
  76. Swift trigger 530214: uncertain if real or not
  77. Swift-BAT trigger 529813 is due to noise while entering the SAA
  78. GRB 120728A: Fermi GBM observation
  79. GRB 120805A: Swift-BAT refined analysis
  80. GRB 120802A: Swift/UVOT Upper Limits
  81. GRB 120805A: Swift-XRT refined Analysis
  82. GRB 120805A: TAROT Calern observatory optical observations
  83. GRB 120805A: Swift detection of a burst
  84. GRB 120804A: EVLA Detection
  85. GRB 120804A: Gemini-North observations
  86. GRB 120803B: Swift-XRT refined Analysis
  87. GRB 120804A: Swift/UVOT Upper Limits
  88. GRB 120804A: Swift-BAT refined analysis
  89. GRB 120804A: Swift-XRT refined Analysis
  90. GRB 120804A: GROND upper limits
  91. GRB 120804A: Swift detection of a short burst
  92. GRB 120803B: Swift-BAT refined analysis
  93. GRB 120803A: Swift-XRT Observations
  94. GRB 120803A: Swift-BAT refined analysis
  95. GRB 120803B: FTN possible afterglow candidate
  96. GRB 120803B: Swift detection of a burst
  97. GRB 120803A: Swift detection of a possible burst
  98. GRB 120802A: GRT Optical Observation
  99. GRB 120802A: Swift-XRT refined Analysis
  100. GRB 120729A: Fermi GBM observation

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