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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"

6667 results found.

  1. GRB 131014A: NOT afterglow candidate
  2. GRB 131014A: Fermi-LAT detection
  3. GRB 131014A: Fermi GBM detection
  4. GRB 131011A: Fermi GBM detection
  5. Swift-XRT detection of iPTF 13dsw/Fermi403206457
  6. Fermi403206457: NOT optical observations
  7. GRB 131004A: MOSFIRE NIR imaging
  8. GRB 131004A: Fermi GBM observation
  9. GRB 131004A: Swift-XRT refined Analysis
  10. GRB 131004A: Liverpool Telescope optical afterglow observations
  11. GRB 131002A: Fermi GBM observation
  12. GRB 131002B: Swift-XRT Refined Analysis
  13. GRB 131002A: Swift-XRT refined Analysis
  14. GRB 130925A: continuing Swift/XRT monitoring
  15. GRB 130929A: Swift-XRT refined Analysis
  16. Fermi LAT Upper Limits on GRB 130925A
  17. GRB 130925A: Swift/UVOT Detection of the Host Galaxy
  18. GRB 130925A: Fermi GBM Detection
  19. GRB 130925A: Historical non-detection from Rosat-HRI
  20. Fermi GBM detection of GRB 130925A and a possible precursor
  21. GRB 130925A: Swift-XRT refined Analysis
  22. GRB 130831A: RTT150 optical observations
  23. GRB 130702A: RTT150 optical observations
  24. GRB 130907A: Maidanak optical observations
  25. GRB 130903A: Further Swift XRT observations.
  26. GRB 130606A: Chandra observation
  27. GRB 130912A: Swift-XRT refined Analysis
  28. GRB 130912A: Fermi GBM detection
  29. GRB 120419A: Swift XRT confirmation of the afterglow
  30. GRB 130907A: T21 optical observations
  31. GRB 130907A: Swift-XRT refined Analysis
  32. GRB 120916A: Fermi-LAT detection of a burst
  33. Swift follow-up results of the possible weak INTEGRAL GRB
  34. GRB 130903A: Swift/UVOT Upper Limits
  35. Swift follow-up of an INTEGRAL possible weak GRB
  36. GRB 130903A: Fermi GBM observation
  37. GRB 130903A: Swift-XRT observations
  38. Swift trigger 569022 is a new Galactic source Swift J1734.5-3027
  39. GRB 130831A: Optical Observations via Virtual Telescope, follow-up
  40. GRB 130831A: T100 observations
  41. GRB 130831B: Swift-XRT refined Analysis
  42. GRB 130831A: Optical Observations via Virtual Telescope
  43. GRB 130831A: Swift-XRT refined Analysis
  44. GRB 130831A: MITSuME Akeno Optical observation
  45. GRB 130828A: Swift XRT and UVOT observations
  46. GRB 130828A: Fermi GBM detection
  47. GRB 130828A: Fermi-LAT detection of a burst
  48. GRB 130821A: Swift-XRT observation
  49. GRB 130822A: Swift-XRT refined Analysis
  50. GRB 130821A: Fermi-LAT detection of a burst
  51. GRB 130821A: Fermi GBM Detection
  52. GRB 130816A: Swift-XRT refined Analysis
  53. GRB 130816A: Fermi GBM observation
  54. GRB 130816B: Swift-XRT refined Analysis
  55. GRB 130812A: Swift-XRT refined Analysis
  56. GRB 130807A: Swift-XRT refined analysis
  57. GRB 130807A, Swift-BAT refined analysis
  58. GRB 130623A: GROND detection of the optical/NIR afterglow
  59. GRB 130806A: Swift-XRT refined Analysis
  60. GRB 130804A; Fermi GBM observation
  61. GRB 130803A: Swift-XRT refined Analysis
  62. GRB 130803A; Fermi GBM observation
  63. GRB 130727A: Swift-XRT refined Analysis
  64. GRB 130727A: Fermi GBM detection
  65. GRB 130725A: Swift-XRT refined Analysis
  66. GRB 130725B: Swift-XRT refined Analysis
  67. Swift Trigger 563980 is GRB 130725A
  68. GRB 130722A: Swift-XRT refined Analysis
  69. GRB 130716A: Fermi GBM observation
  70. GRB 130702A : Xinglong TNT continue optical observation
  71. GRB 130715A: Fermi GBM detection
  72. GRB 130708A: Fermi GBM observation
  73. GRB 130702A: Xinglong TNT optical observation
  74. GRB 130702A: further Swift-XRT observations
  75. GRB 130702A: TNG optical observations
  76. Fermi GRB 130702A: Swift XRT and UVOT observations
  77. GRB 130702A / Fermi394416326: Fermi GBM detection
  78. GRB 130702A / Fermi394416326 : Fermi-LAT detection of a burst
  79. GRB 130628A: Fermi GBM detection
  80. Fermi394416326: iPTF detection of a possible optical afterglow
  81. GRB 130627B: Swift afterglow confirmation
  82. GRB 130623A: Second Swift-XRT observation
  83. GRB 130701B: Fermi GBM detection
  84. GRB 130701A: Swift-XRT refined Analysis
  85. GRB 130627A: Swift-XRT refined Analysis
  86. GRB 130627B: Possible Swift-XRT afterglow detection
  87. GRB 130627A: Fermi GBM detection
  88. GRB 130623A: Fermi GBM detection
  89. GRB 130627B: Swift-XRT observations
  90. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  91. GRB 130625A: Swift-XRT refined Analysis
  92. GRB 130623A: Swift-XRT and UVOT observations
  93. GRB 130615A: Continued Skynet/PROMPT Observations
  94. GRB 130615A: Swift-XRT refined Analysis
  95. GRB 130614A: Fermi GBM detection
  96. GRB 130612A: Fermi GBM observation
  97. GRB 130612A: iTelescope T21 optical observations
  98. GRB 130610A: iTelescope T21 optical observations
  99. GRB 130612A: Swift-XRT refined Analysis
  100. GRB 130612A: PAIRITEL NIR Afterglow Observations

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