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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"

27401 results found.

  1. Swift Trigger 575905: a possible GRB
  2. GRB 131024B, Swift-BAT refined analysis
  3. GRB 131024B: Fermi GBM observation
  4. GRB 131024B: RATIR Optical and NIR Observations
  5. GRB 131024B: Swift/UVOT Upper Limits
  6. GRB 131024B: Swift-XRT refined Analysis
  7. Fermi GBM trigger 13121024.436 is not a GRB
  8. GRB 131024B: Nanshan optical upper limit
  9. GRB 131024A: Swift/UVOT Upper Limits
  10. GRB 131024A: Swift-XRT refined Analysis
  11. GRB 131024B: Swift detection of a burst
  12. GRB 131024A, Swift-BAT refined analysis
  13. GRB 131024A: Skynet R-COP optical observations
  14. Konus-Wind observation of GRB 131011B
  15. IPN triangulation of GRB 131011B (Swift Trigger 574266)
  16. GRB 131024A: Swift detection of a burst
  17. GRB 131014A: RATIR Optical/NIR Afterglow Retraction
  18. IPN Triangulation of GRB 131014A
  19. GRB 131018B: Swift/UVOT Upper Limits
  20. GRB 131018B: Swift-XRT observations
  21. GRB 131018B: Fermi GBM observation
  22. GRB 131018A: RATIR Optical and NIR Observations
  23. GRB 131018A: Swift/UVOT Upper Limits
  24. GRB 131018B: Fermi-LAT detection of a burst
  25. GRB 131018A: Swift-XRT refined Analysis
  26. GRB 131018A, Swift-BAT refined analysis
  27. GRB131018A, optical observations
  28. GRB 131018A: Swift detection of a burst
  29. GRB 131014A: RATIR Optical/NIR Afterglow Confirmation
  30. Fermi GBM data availability during U.S. government shutdown
  31. GRB 131014A: Swift-XRT refined Analysis
  32. GRB 131011A: Swift/UVOT Upper Limits
  33. Fermi 403206457 / GRB 131011A: AAO optical observations
  34. GRB 131014A: RATIR Optical and NIR Observations
  35. GRB 131014A: NOT afterglow candidate
  36. GRB 131014A: Nanshan optical observations
  37. GRB 131014A: Fermi-LAT detection
  38. GRB 131014A: Fermi GBM detection
  39. GRB 131011A: Fermi GBM detection
  40. iPTF 13dsw/Fermi403206457: X-Shooter redshift
  41. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  42. Fermi403206457: continued P60 observations and fading behavior
  43. Fermi403206457: Weihai optical upper limit
  44. Fermi403206457: NOT optical observations
  45. Fermi403206457: iPTF detection of a possible optical afterglow
  46. Trigger 574266 is not a Swift detection of a known source
  47. GRB 130831A: Continued RATIR Optical and NIR Observations
  48. GRB 131004A: MOSFIRE NIR imaging
  49. GRB 131004A: Skynet PROMPT/DSO-14 upper limits
  50. GRB 131004A, Swift-BAT refined analysis
  51. GRB 131004A: Fermi GBM observation
  52. GRB 131004A: Swift/UVOT Detection
  53. GRB 131004A: RATIR Optical and NIR Upper Limits
  54. GRB 131004A: Swift-XRT refined Analysis
  55. GRB 131004A: GROND observations of the afterglow
  56. GRB 131004A: Liverpool Telescope optical afterglow observations
  57. GRB 131004A: Swift detection of a burst (may be short)
  58. GRB 131002A, Swift-BAT refined analysis
  59. GRB 131002A: Fermi GBM observation
  60. GRB 131002B, Swift-BAT refined analysis
  61. GRB 131002B: GROND upper limits
  62. GRB 131002B: Swift-XRT Refined Analysis
  63. GRB 131002B: Swift/UVOT Upper Limits
  64. GRB 131002A: Swift/UVOT Detection
  65. GRB 131001A, Swift-BAT refined analysis
  66. GRB 131002A: Swift-XRT refined Analysis
  67. GRB 131002A: ISON-NM optical observations
  68. Swift J1242.9-3530, Swift-BAT refined analysis
  69. GRB 131001A: Swift UVOT and XRT Upper Limits
  70. NuSTAR observations of GRB 130925A
  71. Fermi Gamma-ray Burst Monitor trigger 402405063 / 131002466 is not a GRB
  72. GRB 131002B: Swift detection of a burst
  73. GRB 131002A: Swift detection of a burst
  74. GRB 131002A: Faulkes Telescope North optical afterglow
  75. GRB 131001A detected in ground analysis of Swift-BAT data
  76. GRB 130925A: continuing Swift/XRT monitoring
  77. IPN Observations of GRB 130925A
  78. GRB 130930A: Swift detection of a burst
  79. GRB 130929A: Swift/UVOT Upper Limits
  80. GRB 130831A: Continued RATIR Optical and NIR Observations
  81. GRB 130929A: Swift-XRT refined Analysis
  82. GRB 130929A, Swift-BAT refined analysis
  83. GRB 130929A: TAROT La Silla observatory optical observations
  84. GRB 130929A: Swift detection of a burst
  85. Fermi LAT Upper Limits on GRB 130925A
  86. GRB 130925A: Swift/UVOT Detection of the Host Galaxy
  87. GRB 130925A: Swift/UVOT Upper Limits
  88. GRB 130925A: Continued RATIR Optical and NIR Observations
  89. GRB 130925A: Fermi GBM Detection
  90. Konus-Wind observation of GRB 130925A
  91. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  92. GRB 130925A: RATIR Optical and NIR Observations
  93. GRB 130925A Swift-BAT refined analysis
  94. Fermi GBM detection of GRB 130925A and a possible precursor
  95. GRB 130925A: Swift-XRT refined Analysis
  96. GRB 130925A: Initial Similarities to Swift J1644+57
  97. GRB 130925A: TAROT La Silla observatory optical observations
  98. GRB 130925A: VLT/X-shooter redshift
  99. GRB 130925A: VLT/UVES observations
  100. GRB 130925A: GROND afterglow candidate

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