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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28048 results found.

  1. GRB 091215: Faulkes Telescope North observations
  2. Trigger 379449: Swift detection of a possible burst
  3. GRB 091208A: Suzaku WAM observation of the prompt emission
  4. GRB 091208A: GAO 150cm telescope Optical Observation
  5. GRB091208A: Swift/UVOT refined analysis
  6. GRB 091208B: optical observations
  7. GRB 091208B: GROND observations
  8. GRB 091208A: Swift-XRT observations
  9. GRB091208B: NOT optical observations
  10. GRB 091208B: Swift-XRT refined analysis
  11. GRB 091208B, Swift-BAT refined analysis
  12. GRB 091208A Swift-BAT refined analysis
  13. GRB 091208A, RIMOTS optical upper limits
  14. GRB 091208B: MITSuME Akeno Optical Observation
  15. GRB 091208B: Enhanced Swift-XRT position
  16. GRB 091208B: MITSuME Okayama Optical Observation
  17. GRB 091208B, RIMOTS optical upper limits
  18. GRB 091208B: Swift detection of a burst with an optical afterglow
  19. GRB 091208B: BOOTES-3 optical afterglow
  20. Short X-ray Transient, RIMOTS optical upper limits
  21. GRB 091123: Suzaku WAM observation of the prompt emission
  22. GRB 091202: GTC & CAHA optical/nIR afterglow candidate
  23. GRB 091109A: GROND confirmation of redshift z = 3.5
  24. GRB 091127, SMARTS optical/IR afterglow observations
  25. GRB091202: Swift-XRT refined analysis
  26. GRB 091202: Swift/UVOT Upper Limits
  27. GRB 091202: Optical and NIR observations
  28. GRB 091202 - UVOT-enhanced XRT position
  29. GRB 091127: Zadko Telescope Observations
  30. GRB 091126A: Suzaku WAM observation of the prompt emission
  31. GRB 091202: TAROT Calern observatory optical observations
  32. GRB 091117: Chandra Observations
  33. Konus-Wind observation of very long GRB 091123
  34. GRB 091123: Fermi GBM detection of a very long burst
  35. GRB 091126B: Fermi GBM detection
  36. GRB 091127: Suzaku WAM observation of the prompt emission
  37. GRB 091126: Fermi GBM detection
  38. GRB 091130B: Swift-XRT team refined analysis
  39. GRB 091130B: Swift-BAT refined analysis
  40. GRB 091130B: Swift/UVOT Upper Limits
  41. GRB 091127: Skynet/PROMPT Observations of Fading
  42. GRB 091130B: Enhanced Swift-XRT position
  43. Swift trigger 377436 (possible GRB 091130A) is not a burst
  44. GRB 091130B: Swift detection of a burst
  45. GRB 091127: Radio observations
  46. GRB 091128: Fermi GBM detection
  47. GRB 091127: TAROT La Silla observatory optical observations
  48. GRB 091127: LABOCA/APEX submm observations
  49. GRB 091127: Further NOT optical observations
  50. GRB 091127: Fermi GBM detection
  51. GRB 091127: Swift-XRT afterglow detection and analysis
  52. GRB 091127: TAROT La Silla observatory optical decay
  53. GRB 091127: Swift/UVOT observations
  54. GRB 091127: Swift-BAT refined analysis
  55. GRB 091127: NOT observations
  56. GRB 091127 : GROND observations
  57. GRB 091127: REM NIR afterglow detection
  58. GRB 091127: Swift/UVOT Detection of an Optical Afterglow
  59. GRB 091127: Swift detection of a burst
  60. GRB 091120: Fermi GBM observation
  61. GRB 091117A: Suzaku WAM observation of the prompt emission
  62. GRB 091117: TNG optical observations
  63. GRB 091117A: Swift/UVOT followup observations
  64. GRB 091117: VLA radio observations
  65. GRB 091117: Swift-XRT observations
  66. GRB 091117 BAT refined analysis
  67. GRB 091117: Evidence for Variability of XRT Source #1
  68. GRB091117: Gemini South Observations
  69. GRB 091117: Swift XRT refined analysis
  70. GRB 091112: Suzaku WAM observation of the prompt emission
  71. GRB 091102A: Suzaku WAM observation of the prompt emission
  72. GRB 091109B: Suzaku WAM observation of the prompt emission
  73. GRB091111: Swift XRT refined analysis
  74. GRB 091112: Swift-BAT refined analysis
  75. GRB 091031: Fermi LAT detection of a faint burst
  76. GRB 091111: BOOTES-3 contemporaneous imaging
  77. GRB 091111: BOOTES-3 observations
  78. GRB 091109A: GROND and VLT observations
  79. GRB 091109B: Swift/UVOT Upper Limits
  80. GRB 091109B: Swift-XRT Team refined analysis
  81. GRB 091109B: Swift-BAT refined analysis
  82. GRB 091109B: Enhanced Swift-XRT position
  83. GRB 091109B: Optical limits from Watcher
  84. GRB 091109B: ROTSE-III Optical Limits
  85. GRB 091109B: Swift detection of a short burst
  86. GRB 091030: Fermi GBM detection
  87. GRB 091109: Swift-XRT refined analysis
  88. GRB 091109: BOOTES-3 observations
  89. GRB 091109: Swift/UVOT observations
  90. GRB 091109: Faulkes Telescope South observations
  91. GRB 091109: Swift-BAT refined analysis
  92. GRB 091109: Enhanced Swift-XRT position
  93. GRB091109: REM detection of the NIR afterglow
  94. GRB 091109: Swift detection of a burst with optical afterglow
  95. GRB 091029: Observations from Stardome Observatory
  96. GRB 091104: Swift-BAT refined analysis
  97. GRB 091104: Swift XRT Refined Analysis
  98. GRB 091104: Swift/UVOT Upper Limits
  99. GRB 091104: Enhanced Swift-XRT position
  100. GRB 091104: Swift detection of a burst

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