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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"

32501 results found.

  1. Konus-Wind observation of GRB 090929B
  2. GRB 090927: Fermi GBM observation
  3. GRB 090929B: Swift-XRT refined analysis
  4. GRB 090926A: Fermi LAT and GBM refined analysis
  5. GRB 090929B: Gemini-N upper limits
  6. GRB 090929B: Skynet/DSO Observations
  7. GRB 090929B: Swift/UVOT Observations
  8. Konus-RF observation of GRB 090929A
  9. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  10. GRB 090929A BAT location of the Fermi GBM burst
  11. Correction: GRB 090929B: Enhanced Swift-XRT position
  12. GRB090926A: Swift-XRT refined analysis
  13. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  14. Konus-Wind and Konus-RF observations of GRB 090926A
  15. GRB 090927: VLT redshift
  16. GRB 090926B: Fermi GBM detection
  17. GRB 090927: Zadko Telescope observations
  18. GRB 090927, Swift-BAT refined analysis of the possibly short burst
  19. Swift/UVOT observations of GRB 090927
  20. GRB 090926A: Skynet/PROMPT Continued Observations
  21. GRB 090927: Swift XRT refined analysis
  22. GRB 090926A: Suzaku WAM observation of the prompt emission
  23. GRB090926B: Swift/UVOT Upper Limits
  24. GRB090926A: Swift/UVOT observations
  25. GRB 090926B: VLT spectroscopy
  26. GRB 090926B: optical object in error circle
  27. GRB 090926B: MAXI GSC detection
  28. GRB 090926A: VLT/X-shooter redshift
  29. GRB 090926B: NOT optical observation
  30. GRB 090926B: Swift XRT refined analysis
  31. GRB 090926B: Swift-BAT refined analysis
  32. GRB 090926A: Swift/UVOT detection of an optical afterglow
  33. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  34. GRB090922A: correction to Fermi location
  35. GRB 090715B: Skynet/PROMPT Detections
  36. GRB 090726: Skynet/GORT Observations
  37. GRB 090916: Swift-XRT upper limit
  38. GRB 090807: Skynet/DSO Observations
  39. GRB 090915: GROND upper limits
  40. Short-Duration GRB 090916: Skynet/PROMPT Observations
  41. GRB 090915: SARA detection of afterglow candidate
  42. GRB 090912: optical observation
  43. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  44. GRB 090702: Skynet/GORT Observations
  45. GRB 090902B: Skynet/PROMPT Observations
  46. GRB 090916, Swift-BAT refined analysis
  47. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  48. GRB 090827: Confirmation of the X-ray afterglow
  49. GRB 090912: Swift-XRT refined analysis
  50. GRB 090912, Swift-BAT refined analysis
  51. GRB 090912: Swift/UVOT Upper Limits
  52. GRB 090912 optical upper limit
  53. GRB 090910: Fermi GBM detection
  54. GRB 090814A: Skynet/DSO & GORT Observations
  55. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  56. GRB 090904B: GROND detection of the optical afterglow
  57. GRB 090831A: Suzaku WAM observation of the prompt emission
  58. GRB 090904A: Swift/UVOT Refined Analysis
  59. GRB 090904B: Swift/UVOT Refined Analysis
  60. GRB 090902B: Suzaku WAM observation of the prompt emission
  61. GRB 090904B: Fermi GBM detection
  62. GRB 090904A: Swift-XRT refined analysis
  63. GRB 090904B: Swift XRT Refined Analysis
  64. GRB 090904B: MOA-II Optical observation
  65. GRB 090904A: Enhanced Swift XRT position
  66. GRB 090904B: Swift-BAT refined analysis
  67. GRB 090902B: VLA radio detection
  68. GRB 090904A: Swift-BAT refined analysis
  69. GRB090904A: Correction to enhanced XRT position
  70. GRB 090904A: NOT observations
  71. GRB 090902B: WSRT Radio Observation
  72. GRB 090904B: Swift detection of a burst
  73. GRB 090904A: ROTSE-III Optical Limits
  74. GRB 090902B: Swift/UVOT refined analysis
  75. GRB090902B: Swift XRT refined analysis
  76. GRB 090902B: Faulkes Telescope North observations
  77. GRB 090902B: GROND NIR Afterglow Observations
  78. GRB 090902B: Gemini-N absorption redshift
  79. GRB 090902B: Fermi LAT and GBM refined analysis.
  80. GRB 090902B: Optical afterglow candidate
  81. GRB090902B: Swift/UVOT observations
  82. GRB 090902B: Swift/XRT Afterglow Candidate
  83. GRB 090831A: IPN Triangulation
  84. GRB 090831C BAT refined analysis
  85. GRB 090831C: GROND upper limits
  86. Konus-Wind observations of GRB 090831A
  87. Swift Trigger 361477, called GRB090831B, is probably not real.
  88. GRB090831C: Swift/UVOT upper limits
  89. GRB 090831B: MITSuME optical upper limits
  90. GRB 090831C: Swift XRT Refined Analysis
  91. GRB 090831B, RIMOTS optical upper limits
  92. GRB 090831: MAXI GSC detection
  93. Konus-Wind observations of GRB 090827
  94. GRB 090827: Swift XRT and UVOT observations
  95. GRB 090817 - TLS Observations
  96. GRB090817: Keck/LRIS Spectroscopy
  97. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  98. GRB 090823: Confirmation of Swift-BAT position by BAT Slew Survey
  99. GRB 090823 Correction to BAT position
  100. GRB 090817: No host galaxy, no supernova

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