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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"
  1. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  2. GRB 090916: Swift detection of a short burst
  3. GRB 090915 Swift-BAT detection of a burst in ground analysis
  4. GRB 090827: Confirmation of the X-ray afterglow
  5. GRB 090912: Swift-XRT refined analysis
  6. GRB 090912, Swift-BAT refined analysis
  7. GRB 090912: Swift/UVOT Upper Limits
  8. GRB 090912 optical upper limit
  9. GRB 090912: Enhanced Swift-XRT position
  10. GRB 090912: Swift detection of a burst
  11. GRB 090910: Fermi GBM detection
  12. GRB 090814A: Skynet/DSO & GORT Observations
  13. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  14. GRB 090904B: GROND detection of the optical afterglow
  15. GRB 090831A: Suzaku WAM observation of the prompt emission
  16. GRB 090904A: Swift/UVOT Refined Analysis
  17. GRB 090904B: Swift/UVOT Refined Analysis
  18. GRB 090902B: Suzaku WAM observation of the prompt emission
  19. GRB 090829A: Suzaku WAM observation of the prompt emission
  20. GRB 090904B: Fermi GBM detection
  21. GRB 090904A: Swift-XRT refined analysis
  22. GRB 090904B: Swift XRT Refined Analysis
  23. GRB 090904B: MOA-II Optical observation
  24. GRB 090904A: Enhanced Swift XRT position
  25. GRB 090904B: Swift-BAT refined analysis
  26. GRB 090902B: VLA radio detection
  27. GRB 090904A: Swift-BAT refined analysis
  28. GRB 090904B: Enhanced Swift-XRT position
  29. GRB090904A: Correction to enhanced XRT position
  30. GRB 090904A: Enhanced Swift-XRT position
  31. GRB 090904A: NOT observations
  32. GRB 090902B: WSRT Radio Observation
  33. GRB090904B: REM observations
  34. GRB 090904B: Swift detection of a burst
  35. GRB 090904A: ROTSE-III Optical Limits
  36. GRB 090904: Swift detection of a burst
  37. GRB 090902B: ROTSE-III Detection of Optical Afterglow
  38. GRB 090902B: Swift/UVOT refined analysis
  39. GRB090902B: Swift XRT refined analysis
  40. GRB 090902B: Faulkes Telescope North observations
  41. GRB 090902B: GROND NIR Afterglow Observations
  42. GRB 090902B: Gemini-N absorption redshift
  43. GRB 090902B: Fermi LAT and GBM refined analysis.
  44. GRB 090902B: Enhanced Swift-XRT position
  45. GRB 090902B: Optical afterglow candidate
  46. GRB090902B: Swift/UVOT observations
  47. GRB 090902B: Swift/XRT Afterglow Candidate
  48. GRB 090902B: Fermi LAT detection
  49. GRB 090902B: Fermi GBM detection of a bright burst
  50. GRB 090902: Fermi GBM detection
  51. GRB 090831A: IPN Triangulation
  52. GRB 090831C BAT refined analysis
  53. GRB 090831C: GROND upper limits
  54. Konus-Wind observations of GRB 090831A
  55. Swift Trigger 361477, called GRB090831B, is probably not real.
  56. GRB090831C: Swift/UVOT upper limits
  57. GRB 090831B: MITSuME optical upper limits
  58. GRB 090831C: Swift XRT Refined Analysis
  59. GRB 090829B: Fermi GBM Detection
  60. GRB 090831C: Enhanced Swift-XRT position
  61. GRB 090831C: Swift detection of a burst
  62. GRB 090831B, RIMOTS optical upper limits
  63. GRB 090831: MAXI GSC detection
  64. GRB 090831B: Swift detection of a possible burst
  65. GRB 090831: Fermi GBM detection
  66. GRB090829: Fermi GBM Detection
  67. Konus-Wind observations of GRB 090827
  68. GRB 090827: Swift XRT and UVOT observations
  69. GRB 090827 Burst discovered in BAT ground analysis
  70. GRB 090826: Fermi GBM detection
  71. GRB 090828: Fermi GBM detection
  72. Fermi Gamma-ray Burst Monitor trigger 273123112 is not a GRB
  73. GRB 090817 - TLS Observations
  74. GRB090817: Keck/LRIS Spectroscopy
  75. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  76. GRB 090823: Confirmation of Swift-BAT position by BAT Slew Survey
  77. GRB 090823 Correction to BAT position
  78. GRB 090817: No host galaxy, no supernova
  79. Konus-Wind observations of GRB 090823
  80. GRB 090823 Long burst with IPN triangulation and BAT position
  81. GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
  82. GRB 090820: detection of a strong burst by RT-2 on board CORONAS PHOTON
  83. GRB 090820B: Fermi GBM detection
  84. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  85. GRB 090820: MASTER-Net optical polarization observations
  86. GRB 090820: Fermi GBM Detection of a bright burst.
  87. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  88. GRB 090817: Liverpool Telescope Observations
  89. GRB 090817: optical upper limit
  90. GRB 090817: Confirmation of the X-ray afterglow
  91. GRB 090815C: Swift refined analysis
  92. GRB 090817: Fermi GBM observation
  93. GRB 090817: Swift/UVOT Upper Limits
  94. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis
  95. GRB 090813: I-band observations from 1.5m OSN telescope
  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. GRB 090817: a long GRB localized by INTEGRAL

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