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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"

18435 results found.

  1. GRB 100115A: Swift-XRT candidate afterglow
  2. GRB 100115A detected in ground analysis of Swift-BAT data
  3. GRB 100111A: PAIRITEL NIR Upper Limits
  4. GRB 100111A: Swift UVOT Refined Analysis
  5. GRB 100111A: Swift-BAT refined analysis
  6. GRB 100111A: Enhanced Swift-XRT position
  7. GRB100111A: Swift-XRT refined analysis
  8. GRB 100111A: Fermi GBM observation
  9. GRB 100111A: Swift detection of a burst with an optical afterglow
  10. Swift/BAT Detects an Outburst from XTE J1901+014
  11. Swift Trigger #382159 is due to XTE J1752-223
  12. GRB 100103A: Swift-XRT team refined analysis
  13. GRB 100103A - UVOT-enhanced XRT position
  14. GRB 100103A: Swift/UVOT Upper Limits
  15. GRB 100103A: Correction to Swift position error
  16. GRB 100103A: Swift/XRT position
  17. Swift Trigger 381591: Retraction of Reported UVOT Source
  18. Swift Trigger 381591 is probably not a burst
  19. Swift Trigger 381591: Uncatalogued UVOT Source
  20. GRB 091230: Swift/UVOT Observations
  21. Trigger 381591: Swift detection of a possible burst
  22. GRB 091230: Swift-XRT observation
  23. Swift Trigger 381434 is not a GRB
  24. Trigger 381434: Swift detection of a possible burst
  25. GRB 091221 : IRSF NIR upper limit
  26. GRB 091221: Skynet/PROMPT Detections
  27. GRB 091221: Fermi GBM Observation
  28. GRB 091117: Swift-XRT late time observations
  29. GRB 091221 Swift-BAT refined analysis
  30. GRB091221: Swift/UVOT refined analysis, correction.
  31. GRB 091221: Swift/UVOT refined analysis
  32. GRB 091221: Swift-XRT refined analysis
  33. GRB 091221: Enhanced Swift-XRT position
  34. GRB 091221: UVOT Confirmation of an Optical Afterglow
  35. GRB 091221: ROTSE-III Detection of Optical Counterpart
  36. GRB 091221: Swift detection of a burst
  37. Swift trigger 379449 (possible GRB) is not a burst
  38. Trigger 379449: Swift detection of a possible burst
  39. GRB 091208A: Suzaku WAM observation of the prompt emission
  40. Konus-Wind observation of GRB 091208A
  41. GRB091208A: Swift/UVOT refined analysis
  42. GRB 091208B: optical observations
  43. GRB 091208B: GROND observations
  44. GRB 091208A: Swift-XRT observations
  45. GRB 091208B: Swift-XRT refined analysis
  46. GRB091208B: Swift/UVOT refined analysis
  47. GRB 091208B: Fermi GBM observation
  48. GRB 091208B, Swift-BAT refined analysis
  49. GRB 091208A Swift-BAT refined analysis
  50. GRB 091208B: Faulkes Telescope North and South Optical Afterglow
  51. GRB 091208A, RIMOTS optical upper limits
  52. GRB 091208B: Enhanced Swift-XRT position
  53. GRB 091208B, RIMOTS optical upper limits
  54. GRB 091208B: Swift detection of a burst with an optical afterglow
  55. GRB 091208B: BOOTES-3 optical afterglow
  56. GRB 091208: ROTSE-III Optical Limits
  57. GRB 091208: Swift detection of a burst
  58. GRB091127: Continuing Swift/UVOT Observations
  59. GRB091202: Swift-XRT refined analysis
  60. GRB 091202: Swift/UVOT Upper Limits
  61. GRB 091202 - UVOT-enhanced XRT position
  62. GRB 091127: Zadko Telescope Observations
  63. GRB 091117: Chandra Observations
  64. GRB 091127: Suzaku WAM observation of the prompt emission
  65. GRB 091130B: Swift-XRT team refined analysis
  66. GRB 091130B: Swift-BAT refined analysis
  67. GRB 091130B: Swift/UVOT Upper Limits
  68. GRB 091127: Skynet/PROMPT Observations of Fading
  69. GRB 091130B: Enhanced Swift-XRT position
  70. Swift trigger 377436 (possible GRB 091130A) is not a burst
  71. GRB 091130B: MASTER observations
  72. GRB 091130B: Swift detection of a burst
  73. GRB 091130: Swift detection of a possible burst
  74. GRB 091127: Radio observations
  75. Konus-Wind observation of GRB 091127
  76. GRB 091127: TAROT La Silla observatory optical observations
  77. GRB 091127: optical observations
  78. GRB 091127: Fermi GBM detection
  79. GRB 091127: Gemini-N redshift
  80. GRB 091127: Swift-XRT afterglow detection and analysis
  81. GRB 091127: TAROT La Silla observatory optical decay
  82. GRB 091127: Swift/UVOT observations
  83. GRB 091127: Swift-BAT refined analysis
  84. GRB 091127 : GROND observations
  85. GRB 091127: Swift/UVOT Detection of an Optical Afterglow
  86. GRB 091127: Liverpool Telescope afterglow candidate
  87. GRB 091127: Swift detection of a burst
  88. GRB 091117A: Suzaku WAM observation of the prompt emission
  89. GRB 091117A: Swift/UVOT followup observations
  90. GRB 091117: Swift-XRT observations
  91. GRB 091117 BAT refined analysis
  92. GRB 091117: Evidence for Variability of XRT Source #1
  93. GRB 091117: Swift XRT refined analysis
  94. GRB 091117: Gemini-North spectroscopy of DSS galaxy
  95. Konus-Wind observations of GRB 091117A
  96. GRB 091117: XRT source coincident with a DSS galaxy
  97. GRB 091117A Detected in ground analysis of BAT data and IPN triangulation
  98. GRB 091112: Suzaku WAM observation of the prompt emission
  99. GRB 091102A: Suzaku WAM observation of the prompt emission
  100. GRB 091109B: Suzaku WAM observation of the prompt emission

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