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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"

19415 results found.

  1. GRB 120913B: Swift detection of a burst
  2. GRB 120913A: Swift detection of a burst
  3. GRB 120911A: optical upper limit CrAO
  4. GRB 120911A: optical upper limit ISON-NM
  5. GRB 120911A: Fermi GBM observation
  6. GRB 120911A: Fermi/LAT upper limit
  7. GRB 120911A: Swift/UVOT Upper Limits
  8. GRB 120911A: Swift-XRT refined Analysis
  9. GRB 120911A: Swift-BAT refined analysis
  10. GRB 120911A: Enhanced Swift-XRT position
  11. GRB 120911A: Swift-XRT observations
  12. GRB 120911A: ROTSE-III Optical Limits
  13. GRB 120911A: Swift detection of a burst
  14. GRB 120907A: SMA upper limits
  15. GRB 120908A and GRB 120909A : Fermi/LAT upper limit
  16. GRB 120908A: Swift Observations
  17. GRB 120909A: TAROT La Silla observatory optical observations
  18. GRB 120909A: Pi of the Sky upper limits
  19. GRB 120909A: Fermi GBM observation
  20. Konus-Wind observation of GRB 120909A
  21. GRB 120909A: Swift/UVOT Detection
  22. GRB 120909A: Swift-XRT refined Analysis
  23. GRB 120909A: Swift-BAT refined analysis
  24. GRB 120909A: Enhanced Swift-XRT position
  25. GRB 120909A: GROND detection of the afterglow
  26. Skynet/PROMPT Observations of GRB120909A
  27. GRB 120909A: Swift detection of a burst
  28. GRB 120907A: EVLA observations
  29. GRB 120907A: Swift/UVOT Detection
  30. GRB 120907A: Swift-XRT refined Analysis
  31. GRB 120907A: Enhanced Swift-XRT position
  32. GRB 120907A: Fermi GBM detection
  33. GRB 120907A: Swift-BAT refined analysis
  34. GRB 120907A: NOT optical observations
  35. GRB 120907A MASTER optical observations
  36. GRB 120907A: ROTSE-III Optical Limits
  37. GRB 120907A: Swift detection of a burst with optical counterpart
  38. XMM observations of the short GRB120804A
  39. GRB 120830A: Further Swift Observations
  40. GRB 120830A: catalog source at Uvot position
  41. GRB 120830A: Swift-XRT and UVOT observations
  42. IPN Triangulation of short GRB 120830A
  43. GRB 120830A: Fermi-LAT detection of a short burst
  44. GRB 120819A: Swift/UVOT Upper Limits
  45. GRB 120817A: Swift/UVOT Upper Limits
  46. GRB 120821A: Swift/XRT observations
  47. GRB 120821A: Swift/UVOT Upper Limits
  48. GRB 120821A: GROND upper limits
  49. GRB 120817B - PTF Observations
  50. GRB 120817A: RAPTOR Limits During Gamma-Ray Emitting Interval
  51. GRB 120817B: BAT location in ground analysis and refined analysis
  52. GRB 120819A: Bassano Bresciano Observatory optical observations
  53. GRB 120819A: Swift-BAT refined analysis
  54. GRB 120819A: GROND afterglow confirmation
  55. GRB 120819A: Swift-XRT refined Analysis
  56. GRB 120819A: Enhanced Swift-XRT position
  57. GRB 120819A: MASTER optical observations
  58. GRB 120819A: Swift detection of a burst
  59. GRB 120817B: Swift-XRT observations
  60. GRB 120816A: Swift/UVOT Detection of the Optical Afterglow
  61. GRB 120815A: MASTER-ICATE observations
  62. IPN Triangulation of GRB 120816B (short/exceptionally intense)
  63. GRB 120817A: Swift-XRT refined Analysis
  64. IPN Triangulation of GRB 120817B (short/very intense)
  65. GRB 120817A: Swift-BAT refined analysis
  66. GRB 120816A: optical upper limit
  67. GRB 120817A: Enhanced Swift-XRT position
  68. GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
  69. GRB 120816A: Bassano Bresciano Observatory optical observations
  70. GRB 120816A: Swift-XRT refined Analysis
  71. GRB 120817A: Swift-XRT observations
  72. GRB 120817A: Swift detection of a burst
  73. GRB 120816A: Enhanced Swift-XRT position
  74. GRB 120816A: Swift-BAT refined analysis
  75. GRB 120816A: TAROT Calern observatory optical observations
  76. GRB 120816A: ROTSE-III Optical Limits
  77. GRB 120816A: Swift detection of a burst
  78. GRB 120815A: Swift-XRT refined Analysis
  79. GRB 120815A: Swift-BAT refined analysis
  80. GRB 120815A: Enhanced Swift-XRT position
  81. GRB 120815A: GROND afterglow candidate
  82. GRB 120815A: Swift-XRT observations
  83. GRB 120815A: TAROT La Silla observatory optical observations
  84. GRB 120815A: Swift detection of a burst
  85. GRB 120804A: Possible temporal break in the X-ray light-curve
  86. GCN for GRB 120811C
  87. GRB 120811A: Swift/XRT-UVOT Obseravations
  88. GRB120804A: Chandra observations and afterglow detection
  89. GRB 120805A: Enhanced Swift-XRT position
  90. GRB 120811C: EVLA Observations
  91. GRB 120811C: RTT150 optical observations
  92. GRB 120811C: MASTER-Tunka OT observations
  93. GRB 120811C: Swift-BAT refined analysis
  94. GRB 120811A: Swift-BAT refined analysis
  95. GRB 120811C: Bassano Bresciano Observatory optical observations
  96. GRB 120811C: Swift-XRT refined Analysis
  97. GRB 120811C: Swift/UVOT Detection
  98. Improved IPN error box for short hard GRB 120811B
  99. GRB 120811C: RTT150 optical observations
  100. GRB 120811C: Enhanced Swift-XRT position

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