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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"

19595 results found.

  1. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  2. GRB090926A: UVOT-enhanced XRT position
  3. GRB 090926B: Swift detection of a burst
  4. GRB 090926: Fermi LAT detection
  5. GRB090904B : IRSF NIR upper limit
  6. Swift returns to normal operations
  7. GRB 090715B: Skynet/PROMPT Detections
  8. GRB 090916: Swift-XRT upper limit
  9. GRB 090807: Skynet/DSO Observations
  10. Swift-BAT temporarily off-line for a few days
  11. Short-Duration GRB 090916: Skynet/PROMPT Observations
  12. GRB 090912: optical observation
  13. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  14. GRB 090916, Swift-BAT refined analysis
  15. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  16. GRB 090916: Swift detection of a short burst
  17. GRB 090915 Swift-BAT detection of a burst in ground analysis
  18. GRB 090827: Confirmation of the X-ray afterglow
  19. GRB 090912: Swift-XRT refined analysis
  20. GRB 090912, Swift-BAT refined analysis
  21. GRB 090912: Swift/UVOT Upper Limits
  22. GRB 090912: Enhanced Swift-XRT position
  23. GRB 090912: Swift detection of a burst
  24. GRB 090814A: Skynet/DSO & GORT Observations
  25. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  26. GRB 090904B: GROND detection of the optical afterglow
  27. GRB 090904A: Swift/UVOT Refined Analysis
  28. GRB 090904B: Swift/UVOT Refined Analysis
  29. GRB 090904B: Fermi GBM detection
  30. GRB 090904A: Swift-XRT refined analysis
  31. GRB 090904B: Swift XRT Refined Analysis
  32. GRB 090904B: MOA-II Optical observation
  33. GRB 090904A: Enhanced Swift XRT position
  34. GRB 090904B: Swift-BAT refined analysis
  35. GRB 090904A: Swift-BAT refined analysis
  36. GRB 090904B: Enhanced Swift-XRT position
  37. GRB090904A: Correction to enhanced XRT position
  38. GRB 090904A: Enhanced Swift-XRT position
  39. GRB090904B: REM observations
  40. GRB 090904B: Swift detection of a burst
  41. GRB 090904A: ROTSE-III Optical Limits
  42. GRB 090904: Swift detection of a burst
  43. GRB 090902B: Swift/UVOT refined analysis
  44. GRB090902B: Swift XRT refined analysis
  45. GRB 090902B: Faulkes Telescope North observations
  46. GRB 090902B: GROND NIR Afterglow Observations
  47. GRB 090902B: Gemini-N absorption redshift
  48. GRB 090902B: Enhanced Swift-XRT position
  49. GRB 090902B: Optical afterglow candidate
  50. GRB090902B: Swift/UVOT observations
  51. GRB 090902B: Swift/XRT Afterglow Candidate
  52. GRB 090902B: Fermi LAT detection
  53. GRB 090831C BAT refined analysis
  54. GRB 090831C: GROND upper limits
  55. Swift Trigger 361477, called GRB090831B, is probably not real.
  56. GRB090831C: Swift/UVOT upper limits
  57. GRB 090831C: Swift XRT Refined Analysis
  58. GRB 090831C: Enhanced Swift-XRT position
  59. GRB 090831C: Swift detection of a burst
  60. GRB 090831B, RIMOTS optical upper limits
  61. GRB 090831B: Swift detection of a possible burst
  62. GRB 090827: Swift XRT and UVOT observations
  63. GRB 090827 Burst discovered in BAT ground analysis
  64. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  65. GRB 090823: Confirmation of Swift-BAT position by BAT Slew Survey
  66. GRB 090823 Correction to BAT position
  67. GRB 090817: No host galaxy, no supernova
  68. Konus-Wind observations of GRB 090823
  69. GRB 090823 Long burst with IPN triangulation and BAT position
  70. GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
  71. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  72. GRB 090817: Liverpool Telescope Observations
  73. GRB 090817: Confirmation of the X-ray afterglow
  74. GRB 090815C: Swift refined analysis
  75. GRB 090817: Swift/UVOT Upper Limits
  76. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  77. GRB 090817: Swift-XRT observations
  78. GRB 090813: Suzaku WAM observation of the prompt emission
  79. GRB 090812: Suzaku WAM observation of the prompt emission
  80. GRB 090813: CrAO optical obsevations
  81. GRB 090814B: Confirmation of the X-ray afterglow
  82. GRB 090814B: I-band observations from 1.23m CAHA telescope
  83. GRB 090814B: Swift/UVOT Upper Limits
  84. GRB 090814B: Liverpool Telescope Observations
  85. GRB 090814B: Swift-XRT detection of a possible afterglow.
  86. GRB 090814A: Swift/UVOT Observations
  87. GRB 090814A: Swift-XRT Team Refined Analysis
  88. GRB 090814A, RIMOTS optical upper limits
  89. GRB 090814A: Swift-BAT refined analysis
  90. GRB 090814: Enhanced Swift-XRT position
  91. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  92. GRB 090814: Swift detection of a burst
  93. GRB 090813: Fermi GBM observation
  94. GRB 090813: Swift-XRT refined analysis
  95. GRB 090813, Swift-BAT refined analysis
  96. Konus-Wind observations of GRB090813
  97. GRB090813: Swift/UVOT upper limits
  98. GRB 090813: Enhanced Swift-XRT position
  99. GRB 090813: Liverpool Telescope afterglow confirmation
  100. GRB 090813: Swift detection of a burst

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