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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"

25841 results found.

  1. GRB 090927: Swift XRT refined analysis
  2. GRB 090927: Enhanced Swift-XRT position
  3. GRB090926B: Swift/UVOT Upper Limits
  4. GRB090926A: Swift/UVOT observations
  5. GRB 090926B: optical object in error circle
  6. GRB 090926B: MAXI GSC detection
  7. GRB 090926B: NOT optical observation
  8. GRB 090926B: Swift XRT refined analysis
  9. GRB 090926A: Swift/UVOT detection of an optical afterglow
  10. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  11. GRB090926A: UVOT-enhanced XRT position
  12. GRB 090926B: Swift detection of a burst
  13. GRB 090926: Fermi LAT detection
  14. GRB 090926: Fermi GBM detection
  15. GRB 090925: Fermi GBM detection
  16. GRB090922A: correction to Fermi location
  17. GRB 090922A: Fermi GBM detection
  18. GRB 090916: Swift-XRT upper limit
  19. GRB 090915: GROND upper limits
  20. Short-Duration GRB 090916: Skynet/PROMPT Observations
  21. GRB 090915: SARA detection of afterglow candidate
  22. GRB 090912: optical observation
  23. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  24. GRB 090702: Skynet/GORT Observations
  25. GRB 090902B: Skynet/PROMPT Observations
  26. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  27. GRB 090915 Swift-BAT detection of a burst in ground analysis
  28. GRB 090827: Confirmation of the X-ray afterglow
  29. GRB 090912: Swift-XRT refined analysis
  30. GRB 090912: Swift/UVOT Upper Limits
  31. GRB 090912 optical upper limit
  32. GRB 090912: Enhanced Swift-XRT position
  33. GRB 090912: Swift detection of a burst
  34. GRB 090910: Fermi GBM detection
  35. GRB 090814A: Skynet/DSO & GORT Observations
  36. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  37. GRB 090904B: GROND detection of the optical afterglow
  38. GRB 090831A: Suzaku WAM observation of the prompt emission
  39. GRB 090904B: Swift/UVOT Refined Analysis
  40. GRB 090902B: Suzaku WAM observation of the prompt emission
  41. GRB 090829A: Suzaku WAM observation of the prompt emission
  42. GRB 090904B: Fermi GBM detection
  43. GRB 090904A: Swift-XRT refined analysis
  44. GRB 090904B: Swift XRT Refined Analysis
  45. GRB 090902B: VLA radio detection
  46. GRB 090904B: Enhanced Swift-XRT position
  47. GRB 090904A: Enhanced Swift-XRT position
  48. GRB 090904A: NOT observations
  49. GRB090904B: REM observations
  50. GRB 090904B: Swift detection of a burst
  51. GRB 090904: Swift detection of a burst
  52. GRB 090902B: ROTSE-III Detection of Optical Afterglow
  53. GRB 090902B: Swift/UVOT refined analysis
  54. GRB090902B: Swift XRT refined analysis
  55. GRB 090902B: GROND NIR Afterglow Observations
  56. GRB 090902B: Enhanced Swift-XRT position
  57. GRB090902B: Swift/UVOT observations
  58. GRB 090902B: Swift/XRT Afterglow Candidate
  59. GRB 090902B: Fermi LAT detection
  60. GRB 090902B: Fermi GBM detection of a bright burst
  61. GRB 090902: Fermi GBM detection
  62. GRB 090831C: GROND upper limits
  63. Konus-Wind observations of GRB 090831A
  64. Swift Trigger 361477, called GRB090831B, is probably not real.
  65. GRB090831C: Swift/UVOT upper limits
  66. GRB 090831B: MITSuME optical upper limits
  67. GRB 090831C: Swift XRT Refined Analysis
  68. GRB 090829B: Fermi GBM Detection
  69. GRB 090831C: Enhanced Swift-XRT position
  70. GRB 090831C: Swift detection of a burst
  71. GRB 090831B, RIMOTS optical upper limits
  72. GRB 090831: MAXI GSC detection
  73. GRB 090831B: Swift detection of a possible burst
  74. GRB 090831: Fermi GBM detection
  75. GRB090829: Fermi GBM Detection
  76. Konus-Wind observations of GRB 090827
  77. GRB 090827: Swift XRT and UVOT observations
  78. GRB 090827 Burst discovered in BAT ground analysis
  79. GRB 090826: Fermi GBM detection
  80. GRB 090828: Fermi GBM detection
  81. GRB 090817 - TLS Observations
  82. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  83. Konus-Wind observations of GRB 090823
  84. GRB 090820: detection of a strong burst by RT-2 on board CORONAS PHOTON
  85. GRB 090820B: Fermi GBM detection
  86. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  87. GRB 090820: MASTER-Net optical polarization observations
  88. GRB 090820: Fermi GBM Detection of a bright burst.
  89. GRB 090817: Liverpool Telescope Observations
  90. GRB 090817: optical upper limit
  91. GRB 090817: Confirmation of the X-ray afterglow
  92. GRB 090815C: Swift refined analysis
  93. GRB 090817: Fermi GBM observation
  94. GRB 090817: Swift/UVOT Upper Limits
  95. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  96. GRB 090817: Swift-XRT observations
  97. GRB 090814A: optical observations
  98. GRB 090813: Suzaku WAM observation of the prompt emission
  99. GRB 090812: Suzaku WAM observation of the prompt emission
  100. VLA radio non-detection of GRB 090812

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